Astrometric Measurements of Ten Double Stars: Report of May 2012 2 Joseph M

Home , 111 Herculis, Chi Tauri, Iota Cassiopeiae

University of South Alabama Vol. 9 No. 1 January 1, 2013 Journal of Double Star Observations Page Journal of Double Star Observations

VOLUME 9 NUMBER 1 January 1, 2013

Inside this issue:

Astrometric Measurements of Ten Double Stars: Report of May 2012 2 Joseph M. Carro Divinus Lux Observatory Bulletin: Report # 27 10 Dave Arnold

Using VizieR to Measure Neglected Double Stars 19 Richard Harshaw

Student Measurements of the Double Star STFA 28AB Compared with 18th - st 21 Century Observations 37 Mark Brewer, Jolyon Johnson, Russell Genet, Anthony Rogers, Deanna Zapata, William Buehlman, Gary Ridge, Hannah Jarrett, Stephen McGaughey, Joseph Carro

CD Double Star Measures, Jack Jones Memorial Observatory: Report #5 43 James L. Jones

Observation and Measurement of 10 Double Stars: April 2012 – July 2012 48 Gaetano Lauritano Comparing Two Calibration Methods of a Micro Guide Eyepiece using STF 1744AB 52 Eric Weise, Jolyon Johnson, Russ Genet, Ryan Gelston, Brian Reinhardt, Tess Downs, Tori Gibson, and Austin Ross Visual Measurements of the Double Star STFA 38 AD Jolyon Johnson, Eric Weise, Russell Genet, Michael Anderson, Samantha Choy, Melinda Hart, Bailey 55 Kelley, Zachery Noble, Samantha Spurlin, Bret Tabrizi, and Sheena Wu Two Cuesta College Teams Observe Albireo Jolyon Johnson, Joseph Carro, Eric Weise, Russell Genet, Brian Cahn, Brittany Chezum, C. McKenney 58 Degnan, Nicole Ford, Anna Greene, Nicholas Jaeger, Rachel Johnson, Kristen Nicholson, Devanee Richards, Joseph Richardson, and Samantha Thompson Six Proper Motion Pairs Measured with the 2-meter Faulkes Telescope North Rafael Caballero , Russell Genet, J.D. Armstrong, Steve McGaughey, Cindy Krach, Audreanna 61 Leatualli, Aaron Rohzinski, Coleen Rohzinski, Eric Rohzinski, Noah Rohzinski, McKayla Wandell, John Martinez, and Thomas Smith

Comparison of Visual Data Collection Techniques on Mizar: The Barlow Lens 69 Holly Bensel, Nolan Peard, Dashton Peccia, David Scimeca

Vol. 9 No. 1 January 1, 2013 Journal of Double Star Observations Page 2

Astrometric Measurements of Ten Double Stars: Report of May 2012

Joseph M. Carro

Cuesta College San Luis Obispo, California

Abstract: From my home in Paso Robles, California, measurements of the separation and position angle of ten double stars were made. The ten double stars were χ Tauri, γ Leporis, STF 630 in Orion, STF 696 in Orion, SAO 44187 in Canes Venatici, SAO 64970 in Corona Borealis, SAO 65262 in Corona Borealis, SAO 83374 in Bootes, SAO 100160 in Coma Beren- ices, and SAO 150336 in Lepus. The two goals of this project were to 1) measure the position angle and separation of the aforementioned double stars, and 2) learn the necessary techniques to conduct this research.

2008) Z = [15.0411 x T average x the cosine of the dec- Methodology lination angle] divided by the number of reticle divi- Observations were made from my home in Paso sions. The formula can be expressed as: Robles, California (located at approximately 35O 37’ 36” N and 120O 41’ 24” W) using a Celestron model 15.0411T cos(δ ) CPC 1100 telescope. The telescope is computerized, Z = ave motorized, and was fitted with a Celestron Mi- D croGuide 12.5mm astrometric eyepiece. The telescope is of Schmidt-Cassegrain design, with aperture of 11 inches on an alt-azimuth mount. The focal length reported by the manufacturer is 2,800 mm. The Micro Guide eyepiece was oriented with the celestial coordinate system using the primary star of the double star under study. The primary star was positioned on the mark 30, the drive was disabled, and the star was permitted to drift to the outer cir- cle. The scale was rotated until the star lay on the 270 degree mark. The accuracy of this setting was verified by positioning the primary star on the 90 degree mark of the outer circular scale, and allowing the star to drift to the 270 degree mark. Following the orientation, drift times were measured by placing the primary star on the 0 mark of the linear scale, and measuring the drift time from the 0 to the 60 mark using a stop watch precise to ±0.01 seconds. The average drift time was used to calculate the scale constant, using the formula (Frey Figure 1. The author with his Celestron telescope

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Astrometric Measurements of Ten Double Stars: Report of May 2012

Separation measurements were made by placing GC 5292, HD 27638, HIP 20430, HR 1369, SAO the pair of stars on the linear scale at the zero mark, 76573, STF 528, and WDS J04226+2538. Its precise and then counting the number of scale divisions be- coordinates are 0422340.94+253745.5 tween the stars. Because the scale has 60 divisions, it Observations was only possible to estimate to the nearest ¼ divi- The measurements were made on 19 November sion. After each measurement, the double star was 2011, from 6:35 pm to 8:00 pm Pacific Standard Time. repositioned to the next major division, measure- The night was clear and calm, with seeing 3 - 4, a ments were made, and an average and standard de- temperature of 40 - 50 OF, and there was no moon. viation were calculated. After completing the orientation, 12 drift time The position angle measurements were made by measurements were made, with an average value of aligning both stars on the linear scale with the pri- 31.32 seconds, a standard deviation of 0.25 seconds, a mary star at the 30 division, disabling the tracking standard error of the mean of 0.07 seconds, which feature, and then allowing the stars to drift to the resulted in a scale constant of 7.08 arc seconds per circular scales. The crossing of the primary star at the division. outer scale was approximated to the nearest degree Fifteen separation measurements were taken O as the scale has divisions of 5 . Following each meas- with an average of 3.0 divisions, a standard deviation urement, the tracking feature was enabled and the of 0.14 divisions, and a standard error of the mean of process was repeated. 0.04 divisions. The calculated separation was 21.0 In this article, the author defines "seeing" as the arc seconds. number of stars in the Little Dipper seen without an Twelve position angle measurements were taken instrument. with an average value of 20.2O, a standard deviation Chi Tauri of 0.7O, and a standard error of the mean of 0.13O. Historic measurements plus the author’s measure- Introduction ments are given in Table 1. Chi Tauri is a spectroscopic binary star located in the constellation Taurus. The primary component is STF 696 in Orion blue-white with a magnitude of 5.38, and the secon- Introduction dary component is yellow with a magnitude of 7.6. Known since ancient times, the constellation h m s The right ascension is 4 25 35 and the declination Orion is easily recognized and contains a collection of o is +25 37' 45". Other catalog identifiers include 59 large and impressive single and double stars. The Tauri, ADS 3161, BD+25 707, CCDM 04226+2538, white primary star has a magnitude of 5, and the blue secondary star has a magnitude of 6.8. Table 1: Separation (in arc seconds) and Position angle (in The right ascension of the double star is 05h 22m degrees) for χ Tauri. 50s, and its declination is +03O 32’ 40”. Other catalog

Sep PA designations include ADS 3962A, AG +03 632, ALS Reference name (as) (deg) 14774, BD+03 871, GC 6607, HD 35149, HIP 25142, Herschel Double Star List (McEvoy 19.9 27 HR 1770, PPM 148857, SAO 112697, SKY 8533, STF 2011) 1822 data 696, TYC 105-2800-1, UBV 5109, and WDS OAG (as given in the WDS - Tobal+ 19.0 25.0 2003) 1973 data J05228+0333A. Its precise coordinates are OAG (as given in the WDS - Tobal+ 052250.00+033240.0. 19.0 24.0 2003) 1980 data OAG (as given in the WDS - Tobal+ Observations 19.0 25.0 2003) 1985 data These measurements were made on 5 March 2012 OAG (as given in the WDS - Tobal+ 19.2 24.0 from 9:50pm to10:40pm PST. The night was hazy 2003)1996 data and calm. The temperature was 60-55oF with humid- Washington Double Star (Worley+ 1996) 20.2 20 ity of 40%, and the moon was full. Sky Master 2000 Catalog (Meyers, 1997) 19.5 25 After completing the orientation, 9 drift time measurements were made, with an average value of Astrogeek (Burton 2004) 19.1 25 28.72 seconds, a standard deviation of 0.30 seconds, Journal of Double Star Observations and a standard error of the mean of 0.10. The result 19.75 23.5 (Arnold 2009) was a scale constant of 7.19 arc seconds per division. Measurements by the author 2011 21 20 The primary star was placed on the linear scale,

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Astrometric Measurements of Ten Double Stars: Report of May 2012

Table 2: Separation (in arc seconds) and Position angle (in Table 3: Separation (in arc seconds) and Position angle (in degrees) for STF 696 degrees) for STF 630

Sep PA Sep PA Reference name Reference name (as) (deg) (as) (deg) Washington Double Star Catalog (Mason Herschel Double Star (McEvoy 2011) 32.8 31 14.3” 49o 2012) 1782 data 1782 data Washington Double Star Catalog (Mason O A G (Tobal 2003) 1974 data 32.0 34.0 13.7” 53o 2012) 1783 data O A G (Tobal 2003) 1980 data 32.0 33.0 O A G (Tobal 2003) 1971 data 14.0” 50.0o

O A G (Tobal 2003) 1992 data 31.3 30.1 O A G (Tobal 2003) 1980 data 14.0” 50.0o

O A G (Tobal 2003) 1993 data 31.8 32.5 O A G (Tobal 2003) 1992 data 14.7" 53.1o

Eagle Creek (Muenzler 2003) 32 28 O A G (Tobal 2003) 1995 data 14.9" 54.7o

Journal of Double Star Observations o 32.6 29.1 O A G (Tobal 2003)1998 data 15.0" 51.9 (Arnold 2006) Washington Double Star Catalog (Mason Washington Double Star Catalog (Mason, ” o 31.5 30 14.4 49 2009) 2012) Measurements by the author 2012 31.9 30 Tycho 2 (from the WDS site) 14.4” 49.6o

” o and 9 separation measurements were taken. The av- Measurements by the author 2012 14.1 48 erage value was 4.5 divisions with a standard deviation of 0.0 divisions and a standard error of the mean sulted in a scale constant of 7.12 arc seconds per divi- of 0.0 which resulted in a separation of 31.9 arc sec- sion. onds. Twelve separation measurements were taken Ten position angle measurements were taken with an average value was 2 marks with a standard with an average value of 30O, a standard deviation of deviation of 0.1 marks and a standard error of the 0.7O, and a standard error of the mean of 0.1O. His- mean of 0.03. The calculated separation was 14.1 arc toric measurements of STF 696 plus the author’s seconds. measurements are given in Table 2. Twelve position angle measurements were taken with an average value of 48O, a standard deviation of STF 630 in Orion 0.87O, and a standard error of the mean of 0.15O. His- Introduction toric measurements of STF 630 plus the author’s This double star consists of a pair of blue stars, measurements are given in Table 3. with magnitudes of 6.5 and 7.7. The right ascension Gamma Leporis of the double star is 05h 02m 00s, and its declination is +01O 36’ 32”. Introduction Other catalog designations include A 2630 BC, Lepus is a constellation lying just south of the ADS 3623BC, AG +01 518, BD +01 886B, HIP 23421, celestial equator. One of the 48 constellations listed PPM 148338, SAO 112341 SKY#7881, STF 630 TYC by the 2nd century astronomer Ptolemy, it remains as 98-2440-1, and WDS J05020+0137BC. Its precise co- one of the 88 modern constellations. The double ordinates are 050200.03+013631.9. gamma Leporis is a multiple star system and a member of the Sirius moving group of stars. The primary STF 630 - Observations star is a white-yellow dwarf with a magnitude of 6.3, The night of 5 March 2012 was hazy with no wind and the red secondary star has a magnitude of 6.5. and the temperature was 65 - 50 OF. Moon rise oc- Other catalog identifiers include ADS 4334A, BD -22 curred at 7:54 pm so there was little impact even 1211, FK5 217, GC 7197, GCRV 3567, GJ 216A, HD though the moon was 2/3 full. The session began at 38393, HIP 27072, HR 1983, PPM 249307, ROT 920, 6:40 pm and ended at 9:50 pm Pacific Standard Time. SAO 170759, SKY# 9411, SRS 30217, UBV 5897, and After completing the orientation, 9 drift time WDS J05193-1831. Its precise coordinates are measurements were made, with an average value of 054427.79-222654.2 28.72 seconds, a standard deviation of 0.30 seconds and a standard error of the mean of 0.10 which re-

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Astrometric Measurements of Ten Double Stars: Report of May 2012

Table 4: Separation (in arc seconds) and Position angle (in Table 5: Separation (in arc seconds) and Position angle (in degrees) for γ Leporis degrees) for SAO 150336 in Lepus

Sep PA Sep PA Reference name Reference name (as) (deg) (as) (deg) Washington Double Star Catalog (Mason+ 95.8 348 O A G (Tobal+ 2003) 1971 data 40.0 19 2012) 1800 data Washington Double Star Catalog (Mason+ 94 350 O A G (Tobal+ 2003) 1980 data 40.0 18 2012) 1825 data Eagle Creek Observatory (Muenzler O A G (Tobal+ 2003) 1973 data 97 350 39.2 18 2003) Journal of Double Star Observations O A G (Tobal+ 2003) 1980 data 96 351 39.5 18.1 (Anton 2008) Bright Star Catalog (Hoffleit+ 1991) 96.5 '- TYCHO 2 (as listed in the WDS) 39.3 18.5 1991 data Washington Double Star Catalog (Mason+ O A G (Tobal+ 2003) 1994 data first 99 350 39 19 2012) O A G (Tobal+ 2003) 1994 data second 98.6 350 Measurements by the author 2012 38.2 20

O A G (Tobal+ 2003) 1995 data first 97 350 SAO 150336 in Lepus O A G (Tobal+ 2003) 1995 data second 97.8 349.5 Introduction Eagle Creek Observatory (Muenzler 94.9 351 This double star consists of blue primary and sec- 2003) Washington Double Star Catalog (Mason+ ondary stars with magnitudes of 6.3 and 6.5 The right 95.6 348 2012) ascension of the double star is 05h 19m 17s, and its O Tycho 2 (as reported by the WDS) 97 349 declination is -18 31’ 12”. Catalog designations include V* TX Lep, **S 476B, ADS 3910B, ALS 17336, AUTHOR'S data 2012 95 350 BD-18 1056, CCDM J05193-1831B, GC 6525, GCRV 56060, GEN# +1.00034797, HD 34797, HIP 24827, Observations HR 1754, IDS 05149-1837B, 2MASS J05191831- These measurements were made on 9 March 1830344, PPM 215591 ROT 767, SAO 150336, SKY# 2012, from 8:50 pm to 10:00 pm Pacific Standard 8416, TYC 5906-1519-1, UBV M 10844, UVBY98 Time. The night was hazy; the temperature was 60 - 100034797 V, and WDS J05193-1831B. Its precise 50 OF with humidity of 20% and a full moon. coordinates are 042234.94+253745.5. Once the MicroGuide eyepiece orientation was Observations completed, 12 drift time measurements were made, These measurements were made on 9 March 2012 with an average value of 29.51 seconds, a standard from 8:50 pm to 10:00 pm Pacific Standard Time. The deviation of 0.36 seconds and a standard error of the night was hazy and calm with temperatures from 65 mean of 0.10 which resulted in a scale constant of – 55 OF. The moon was full, and there was a gentle 6.85 arc seconds per division. breeze. The stars were placed on the linear scale, and 10 Once the MicroGuide eyepiece orientation was separation measurements were taken. The average completed, 12 drift time measurements were made, value was 13.9 divisions with a standard deviation of with an average value of 29.51 seconds, a standard 0.2 divisions and a standard error of the mean of 0.07. deviation of 0.36 seconds and a standard error of the The average value was used to calculate the separa- mean of 0.10 seconds. The result was a scale con- tion, which was 95 arc seconds. stant of 7.01 arc seconds per division. Twelve position angle measurements were taken The primary star was placed on the linear scale, with an average value of 350O, a standard deviation and 10 separation measurements were taken. The of 0.9O, and a standard error of the mean of 0.2O. His- average value was 5.5 divisions with a standard de- toric measurements of γ Leporis plus the author’s viation of 0.2 divisions and a standard error of the measurements are given in Table 4. mean of 0.05 divisions. The average value was used to calculate the separation, which was 38.2 arc seconds. Eleven position angle measurements were taken with an average value of 20O, a standard devia-

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Astrometric Measurements of Ten Double Stars: Report of May 2012

tion of 0.9O, and a standard error of the mean of 0.2O. of 1.3O, and a standard error of the mean of 0.2O. His- Historic measurements of SΑΟ 150336 plus the au- toric measurements of SΑΟ 44187 plus the author’s thor’s measurements are given in Table 5. measurements are given in Table 6. SAO 44187 in Canes Venatici SAO 100160 in Coma Berenices Introduction Introduction This double star consists of two orange stars with This double star consists of a yellow primary and magnitudes of 7.5 and 8.1. The right ascension is 12h blue secondary star with magnitudes of 5.1 and 6.3. 28m 04s, and its declination is +44o 47’ 39”. Catalog The right ascension is 12h 35m 07s, and its declina- designations include ADS 8561A, ASCC 409178, tion is +18o 22’ 37”. Catalog designations include 24 BD+45 2038, CCDM J12281+4448A, CSI+45 20381 1, COM, ADS 8600A, AG+18 1196, BD+19 2584, CSV GC 16998, GCRV 7495, GSC 03020-02112, HD 101298, GC 17147, GCRV 7572, HD 109511, HIP 108574, HIP 60831, NLTT 30820, PPM 400176, SAO 61418, HR 4792, IRC +20244, N30 2908, NSV 5748, 44187, SKY# 23325, STF 1645, TYC 3020-2112-1, PLX 2902, PMC 90-93 337, PPM 129167, RAFGL UBV 11206, and WDS J12281+4448a. Its precise co- 48535, SAO 100160, SKY# 23522 , STF 1657, TYC ordinates are 122804.45+444739.5. 1446-2469-1, UBV 11303, and WDS J12351+1823A. Observations Its precise coordinates are 123507.76+182237.4. These measurements were made on 20 April Observations 2012 from 8:50 pm to 9:50 pm Pacific Daylight Time. These measurements were made on 21 April 2012 The night was hazy and calm with temperatures from from 8:50pm to 10:00pm Pacific Daylight Time. The 65 – 55 OF and humidity of 55%. There was no moon. night was hazy and calm with temperatures from 70- Once the MicroGuide eyepiece orientation was 65oF and humidity of 65%. There was no moon. completed, 10 drift time measurements were made, Once the MicroGuide eyepiece orientation was with an average value of 39.81 seconds, a standard completed, 10 drift time measurements were made, deviation of 0.62 seconds and a standard error of the with an average value of 30.03 seconds, a standard mean of 0.19 seconds. The result was a scale con- deviation of 0.22 seconds and a standard error of the stant of 7.08 arc seconds per division. mean of 0.07 seconds. The result was a scale con- Twelve separation measurements were taken stant of 7.14 arc seconds per division. which resulted in an average value of 1.4 divisions Twelve separation measurements were taken with a standard deviation of 0.04 divisions and a which resulted in an average value of 3 divisions with standard error of the mean of 0.01 divisions. The av- a standard deviation of 0.08 divisions and a standard erage value was used to calculate the separation, error of the mean of 0.02 divisions. The average value which was 10 arc seconds. was used to calculate the separation, which was 20 Twelve position angle measurements were taken arc seconds. with an average value of 156.9O, a standard deviation Twelve position angle measurements were taken with an average value of 273o, a standard deviation of 1.4o, and a standard error of the mean of 0.3o. His- Table 6. Separation (in arc seconds) and Position Angle (in toric measurements of SΑΟ 100160 plus the author’s degrees) for SAO 44187 in Canes Venatici measurements are given in Table 7. Reference name Sep PA SAO 83374 in Bootes O A G (Comellas+ 2003) 1973 data 10.0” 158o Introduction O A G (Comellas+ 2003) 1980 data 10.0” 157o This double star consists of two blue stars Eagle Creek Observatory (Muenzler 10.2” 158o with magnitudes of 7.11 and 7.56. The right ascen- 2003) sion is 14h 51m 27s, and its declination is +44o 55’ 42”. Journal of Double Star Observations 9.78” 157.3o (Bertoglio 2007) Catalog designations include ADS 9277A, AG+28 1407, BD+28 2332, GCRV 8451, HD 127067, HIC TYCHO 2 (as listed in the WDS) 9.83” 157.6o 70786, HR 5415, N30 3281, PPM 103349, ROT 2080, Washington Double Star Catalog 9.7" 157o SAO 83374, STF 1850, UBV 12680, and WDS (Mason+ 2012) J14286+2817A. Its precise coordinates are Measurements by the author 2012 10" 157o 142833.29+281725.9.

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Astrometric Measurements of Ten Double Stars: Report of May 2012

Table 7. Separation (in arc seconds) and Position Angle (in Table 8. Separation (in arc seconds) and Position Angle (in degrees) for SAO 100160 in Coma Berenices degrees) for SAO 83374 in Bootes

Reference name Sep PA Reference name Sep PA Washington Double Star Cat.(Mason+ o 25.8" 262o O A G (Comellas+ 2003) 1973 data 20” 271 2012) 1823 data Eagle Creek Observatory (Muenzler o 20.3” 271o O A G (Comellas+ 2003) 1973 data 26” 263 2003) Journal of Double Star Observations o 20.14” 270.4o O A G (Comellas+ 2003) 1980 data 26" 262 (Daley 2004) Journal of Double Star Observations o 20.24” 270.5o O A G (Tobal+ 2003) 1991 data 20.3” 271 (Arnold 2007) Journal of Double Star Observations o 19.98" 270.7o O A G (Tobal+ 2003) 1973 data 25.6" 263.4 (Schlimmer 2008) Journal of Double Star Observations O A G (Tobal+ 2003) 1992 data 25.7" 264.6o 20.17" 270.5o (Bertoglio 2010) Journal of Double Star Observations O A G (Tobal+ 2003) 1993 data 25.7" 264o 19.85 270.9o (Schlimmer 2010) O A G (Tobal+ 2003) 1994 data 25.7" 264.2o Astrogeek (Burton 2012) 20.2” 271o Washington Double Star Catalog O A G (Tobal+ 2003) 1995 data 25.6" 263.1o 22.1" 273o (Mason+ 2012) Washington Double Star Catalog 25.6" 262o Measurements by the author 2012 20" 273o (Worley+ 1996) Washington Double Star Catalog 25.2" 261o Observations (Mason+ 2012) These measurements were made on 20 May 2012 Measurements by the author 2012 26" 261o from 9:40pm to 10:40pm Pacific Daylight Time. The night was clear and calm with temperatures from 70- BD+34 2709, CSI +34 2709 2, GC 21385, GCRV 9165, 60oF and humidity of 45%. There was no moon, and HD 142742, HIC 77933, PPM 78912, SAO 64970, STT "seeing" was 3-4. 302, TD1 18686, TYC 2575-1509-1, UBV 13522, and Once the MicroGuide eyepiece orientation was WDS J15549+3422A. Its precise coordinates are completed, 12 drift time measurements were made, 155456.85+3412145.0. with an average value of 32.43 seconds, a standard Observations deviation of 0.19 seconds and a standard error of the These measurements were made on 27 May 2012 mean of 0.05 seconds. The result was a scale con- from 9:30pm to 10:40pm Pacific Daylight Time. The stant of 7.16 arc seconds per division. night was clear and calm with temperatures from 60- Ten separation measurements were taken which 50oF and humidity of 55%. There was in ¼ phase, resulted in an average value of 3.6 divisions with a and "seeing" was 3-4. standard deviation of 0.16 divisions and a standard Once the MicroGuide eyepiece orientation was error of the mean of 0.05 divisions. The average value completed, 10 drift time measurements were made, was used to calculate the separation, which was 26 with an average value of 34.31 seconds, a standard arc seconds. deviation of 0.34 seconds and a standard error of the Twelve position angle measurements were taken mean of 0.11 seconds. The result was a scale con- o with an average value of 261 , a standard deviation of stant of 7.10 arc seconds per division. o o 0.9 , and a standard error of the mean of 0.2 . His- Eleven separation measurements were taken toric measurements of SΑΟ 83374 plus the author’s which resulted in an average value of 4.1 divisions measurements are given in Table 8. with a standard deviation of 0.13 divisions and a SAO 64970 in Corona Borealis standard error of the mean of 0.04 divisions. The average value was used to calculate the separation, Introduction which was 29 arc seconds. This double star consists of a blue-white primary Twelve position angle measurements were taken of magnitude 7.16, and a blue secondary star of mag- with an average value of 50o, a standard deviation of nitude 10.4. The right ascension is 16h 00m 55s, and 0.7o, and a standard error of the mean of 0.1o. Historic its declination is +39o 10' 39”. Catalog designations measurements of SΑΟ 64970 plus the author’s meas- include ADS 9838A, AG+34 1437, AGKR 14207, urements are given in Table 9.

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Astrometric Measurements of Ten Double Stars: Report of May 2012

Table 9. Separation (in arc seconds) and Position angle (in Figure 10. Separation (in arc seconds) and Position angle (in degrees) for SAO 64970 in Corona Borealis degrees) for SAO 64970 in Corona Borealis

Reference name Sep PA Reference name Sep PA Washington Double Star Cat.(Mason+ o Washington Double Star Cat.(Mason+ 28.6" 54 36.4" 21o 2012) 1843 data 2012) 1783 data o O A G (Comellas+ 2003) 1980 data 29" 56 O A G (Comellas+ 2003) 1995 data 32.2" 15o

Journal of Double Star Observations o Eagle Creek Observatory (Muenzler 29.63” 50.8 34.7" 19o (Arnold 2008) 2003) Washington Double Star Catalog o Journal of Double Star Observations 29.6" 51 31.58” 16.5o (Mason+ 2008) (Arnold 2006) o Journal of Double Star Observations Measurements by the author 2012 29" 50 31.26" 15.3o (Bertoglio 2010) Washington Double Star Cat. (Mason+ 31.10" 17o SAO 65262 in Corona Borealis 2012) 2009 data o Introduction Measurements by the author 2012 31" 17 This double star consists of a blue-white primary of magnitude 7.16, and a blue secondary star of mag- adjunct professor of Astronomy at Cuesta College, for h m s nitude 10.4. The right ascension is 15 39 22 , and his instruction about the methodology and instru- o its declination is +36 38' 09”. Catalog designations ment usage. include ADS 9838A, AG+34 1437, AGKR 14207, BD+34 2709, CSI +34 2709 2, GC 21385, GCRV 9165, References HD 142742, HIC 77933, PPM 78912, SAO 64970, STT Anton, R., 2008, "Measurements of Double and Multi- 302, TD1 18686, TYC 2575-1509-1, UBV 13522, and ple Stars", Journal of Double Star Observations, WDS J15549+3422A. Its precise coordinates are vol 2 no 3 155456.85+3412145.0. SAO 65262 in Corona Borealis - Observations Arnold, D. 2006, “Divinus Lux Observatory Bulletin These measurements were made on 28 May 2012 Report #3”, Journal of Double Star Observations, from 9:20pm to 10:40pm Pacific Daylight Time. The vol 2 no 2 night was a little hazy and calm with temperatures Arnold, D. 2006, “Divinus Lux Observatory Bulletin from 60-50oF and humidity of 55%. There was ½ full, Report #4”, Journal of Double Star Observations, and "seeing" was 3. vol 2 no 2 Once the MicroGuide eyepiece orientation was completed, 10 drift time measurements were made, Arnold, D., 2008, Divinus Lux Observatory Bulletin with an average value of 33.7 seconds, a standard report #8; Journal of Double Star Observations deviation of 0.07 seconds and a standard error of the vol 3, no 1 mean of 0.02 seconds. The result was a scale con- Arnold, D., 2008, Divinus Lux Observatory Bulletin stant of 6.78 arc seconds per division. report #12; Journal of Double Star Observations Ten separation measurements were taken which vol 4, no 1 resulted in an average value of 4.6 divisions with a standard deviation of 0.11 divisions and a standard Arnold, D., 2008, Divinus Lux Observatory Bulletin error of the mean of 0.03 divisions. The average value report #14; Journal of Double Star Observations was used to calculate the separation, which was 31 vol 5, no 2 arc seconds. Arnold, D., 2008, Divinus Lux Observatory Bulletin Ten position angle measurements were taken report #17; Journal of Double Star Observations with an average value of 16.7o, a standard deviation vol 5, no 2 of 0.8o, and a standard error of the mean of 0.2o. His- toric measurements of SΑΟ 65262 plus the author’s Bertoglio, A., 2007, "Double Star Measurements Re- measurements are given in Table 10. port 1", Journal of Double Star Observations, vol 6 no 2 Acknowledgements Grateful appreciation is given to Russell Genet,

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Astrometric Measurements of Ten Double Stars: Report of May 2012

Bertoglio, A, 2010, "Capella Observatory CCD Double Schlimmer, J., 2010, “Double Star Measurements Us- Star Measurements – Report 1", Journal of Dou- ing a Webcam Report of 2009”, Journal of Double ble Star Observations, vol. 6 no. 2 Star Observations, vol 6 no 3 Burton, J., 2012, Astrogeek from his website http:// Tycho - 2 catalog, as reported by the WDS x.astrogeek.org/index.php Worley+, 1996, Washington Double Star Catalog Daley, J., 2005, "Double Star Measurements for the Worley+, 2006, Washington Double Star Catalog year 2004", Journal of Double Star Observations, vol 2 no 3 Daley J, 2006, “Double Star Measures for the year 2005”, Journal of Double Star Observations, vol 2 no 2 Frey, Thomas, 2008, “Visual Double Star Measure- ment with an Alt-Azimuth Telescope”, Journal of Double Star Observations, vol 4 no 2 Hipparcos and Tycho Catalogue, 2011 from their website www.rssd.esa.int. Hoffleit+, 1991, The Bright Star Catalogue, 5th Re- vised Edition, Yale University. Martín, E., 2009, "CCD Double-Star Measurements at Observatorio Astronómico Camino de Palomares (OACP): First Series", Journal of Double Star Ob- servations, vol. 5 no. 1 Mason, B.+, 2012, Washington Double Star Catalog McEvoy B., 2011, Herschel 500 Double Star List Muenzler, K., 2003, Eagle Creek Observatory website http://www.eaglecreekobservatory.org Myers, J.+, 1997, SKY 2000 Master Star Catalog, Goddard Space Flight Center. Myers, J.+. 2002, Sky 2000 Master Star Catalog, God- dard Space Flight Center. OAG catalog 2003, as reported by the WDS Perez, J., 2012, from his website http:// www.perezmedia.net SAO Staff, 1996, Smithsonian Astrophysical Observa- tory Star Catalog Schlimmer, J., 2007, “Double Star Measurements Us- ing a Webcam”, Journal of Double Star Observa- tions, vol 3 no 3 Schlimmer, J., 2008, “Double Star Measurements Us- ing a Webcam Report of 2007”, Journal of Double Star Observations, vol 4 no 2

Vol. 9 No. 1 January 1, 2013 Journal of Double Star Observations Page 10

Divinus Lux Observatory Bulletin: Report # 27

Dave Arnold

Program Manager for Double Star Research 2728 North Fox Run Drive Flagstaff, AZ 86004

Email: [email protected]

Abstract: This report contains theta/rho measurements from 120 different double star systems. The time period spans from 2012.189 to 2012.443. Measurements were obtained using a 20-cm Schmidt-Cassegrain telescope and an illuminated reticle micrometer. This report represents a portion of the work that is currently being conducted in double star astronomy at Divinus Lux Observatory in Flagstaff, Arizona.

This article contains a listing of double star the theta value. Perhaps AC warrants further scru- measurements that are part of a series, which have tiny by others in order to determine, more accu- been continuously reported at Divinus Lux Observa- rately, what these parameters actually are. tory, since the spring of 2001. The selected double Some other apparent discrepancies in the star systems, which appear in the table below, have catalog involve the STF 2319 (18277+1918) star sys- been taken exclusively from the 2006.5 version of the tem. To begin with, the measurements for the AC Washington Double Star Catalog, with published components appear to more nearly match the pa- measurements that are no more recent than ten rameters for BC, while the BC measurements appear years ago. There are also some noteworthy items to match the AC parameters. In addition, the theta that are discussed, which pertain to a few of the measurements for AD appear to reflect a quadrant measured systems. flip and the listed measurement more nearly First of all, a significant theta/rho shift, be- matches parameters for BD, rather than AD. The cause of proper motion by one of the components in a table below reflects proposed corrected values for the double star system, is being noted. In particular, STF 2319 components. proper motion by the “A” component, for HJ 162 Aa- B, has caused a rho value increase of 3.7% during the past decade. Also being noted is a listing in the WDS catalog that doesn’t appear to reflect theta/rho values that are obtained at the telescope. Specifically, the proper motion vectors and the measurements for ARN 15 AC (17037+1336) imply that the theta/rho values should be decreasing. However, the catalog values suggest a rho value increase and no change in

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Divinus Lux Observatory Bulletin: Report # 27

NAME RA DEC MAGS PA SEP DATE N

FOR 1AB 12021+4303 5.2 6.6 61.5 275.51 2012.189 1 ARN 5AC 12021+4303 5.2 8.3 24.8 375.25 2012.189 1 FOR 1AD 12021+4303 5.2 8.8 267.6 364.39 2012.189 1 STF1597 12049+0910 9.4 10.5 147.3 30.61 2012.189 2 A 2982A-BC 12072-0605 7.7 10.5 192.6 142.20 2012.189 3 STF1603 12081+5528 7.8 8.2 82.7 22.22 2012.189 4 STF3078 12093+1118 8.5 10.7 303.3 9.38 2012.189 5 STF1616AC 12145+0847 7.5 10.1 296.3 167.88 2012.189 6 STF1619AB 12151-0715 8.0 8.2 266.4 6.91 2012.189 7 BLL 29AB 12154+5702 3.3 10.1 73.2 180.71 2012.189 8 SHJ 143AC 12225+2551 4.8 8.9 166.8 65.18 2012.189 9 ARN 6AD 12225+2551 4.8 10.1 132.2 213.30 2012.189 9 HJ 209 12239-0303 10.6 10.6 146.6 23.70 2012.189 10 FOX 175 12273+0714 8.2 10.0 320.2 62.21 2012.189 11 STF 21AB 12289+2555 5.2 6.6 250.4 145.16 2012.189 12 BUP 143AC 12300+5132 6.2 8.4 333.3 211.33 2012.191 13 SHJ 146AB 12312+0120 7.6 8.6 289.9 49.87 2012.191 14 STF1652 12325+2106 10.1 10.3 178.0 5.93 2012.191 15 HJ 212 12335+1012 10.0 10.1 264.3 21.73 2012.191 16 STF1658AC 12351+0727 8.0 8.9 265.9 128.38 2012.191 17 S 639AB 12387-0422 6.6 9.9 109.3 56.78 2012.191 18 GIR 3AC 12387-0422 6.6 10.1 359.2 164.91 2012.191 18 ENG 47AB 12392-0800 4.6 8.8 136.0 176.76 2012.191 19 ENG 47AD 12392-0800 4.6 8.9 331.3 320.94 2012.191 19 HJ 217AB 12459+1009 10.1 10.4 24.0 33.08 2012.191 20 STT 577 12464+0932 5.6 8.7 209.9 143.19 2012.191 21 BUP 145 12472+1157 6.1 9.9 0.7 139.24 2012.191 22 ENG 49AB 12489+1206 7.1 10.7 348.3 175.78 2012.191 23 STF1658AB 12519+1910 7.3 7.7 201.6 15.80 2012.191 24 SHJ 123AC 12519+1910 7.3 8.1 327.5 241.94 2012.191 24 S 643 12540-1802 7.0 8.1 294.6 23.70 2012.191 25 STF1701 12593+0630 7.5 9.8 305.0 21.23 2012.191 26 BU 112A-BC 13006+1822 6.2 10.1 359.5 139.24 2012.227 27 STF1715 13042+1924 9.9 10.5 232.1 7.41 2012.227 28 STF1719 13073+0035 7.5 8.1 359.1 6.91 2012.227 29 STF1721 13085+0107 10.1 10.2 357.5 6.42 2012.227 30

Table continues on next page.

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Divinus Lux Observatory Bulletin: Report # 27

NAME RA DEC MAGS PA SEP DATE N

HJ 162Aa-B 13149-1122 7.0 8.0 44.6 111.59 2012.227 31 S 649CA 13288+5956 5.5 8.1 110.3 181.70 2012.227 32 STU 25CD 13288+5956 5.5 8.7 60.8 413.76 2012.227 32 ARN 9CE 13288+5956 5.5 10.2 106.8 380.19 2012.227 32 HLM 5 13310+3626 10.0 10.7 160.9 5.93 2012.227 33 SHJ 165 13324-1240 7.6 8.5 78.1 47.89 2012.227 34 STT 269AB-C 13329+3454 6.8 9.1 331.8 123.44 2012.227 35 ARN 8AB-D 13329+3454 6.8 8.3 258.8 351.55 2012.227 35 ODE 11 13337+4801 9.5 9.8 134.9 124.43 2012.227 36 HJ 228 13356+1012 6.5 8.9 15.4 70.11 2012.230 37 STF1769AC 13381+3910 7.8 9.1 258.9 56.29 2012.230 38 STF1773AB 13416+0736 9.9 9.9 209.9 30.12 2012.230 39 STF1773AC 13416+0736 9.9 10.6 101.7 56.29 2012.230 39 HJ 230 13422+1807 10.2 10.6 319.9 63.69 2012.230 40 HJ 2676 13430+5002 7.7 10.0 126.5 27.16 2012.230 41 STF1775AB 13435-0416 7.1 10.0 336.4 27.65 2012.230 42 STF1782 13451+1822 7.9 9.8 185.4 30.12 2012.230 43 STF1793 13591+2549 7.4 8.4 243.1 4.94 2012.230 44 BUP 155AC 13594+2515 10.6 9.7# 91.3 312.05 2012.230 45 ARN 10AD 14016+0133 4.2 9.6 85.2 342.66 2012.265 46 STF1812AB-C 14124+2843 7.8 9.4 107.8 14.32 2012.265 47 STF1850 14286+2817 7.1 7.6 261.3 25.18 2012.265 48 STT 582AB 14347+2945 4.5 10.6 84.9 215.28 2012.265 49 BU 941AB-C 14358+0015 8.6 7.7# 115.7 191.58 2012.265 50 SHJ 186AB 14509-1603 2.7 5.1 313.9 231.08 2012.265 51 H 51AB 14576-0010 5.5 10.2 224.2 86.41 2012.265 52 ARN 13AC 14576-0010 5.5 10.2 173.5 267.61 2012.265 52 SHJ 191 14596+5352 6.8 7.5 341.7 40.49 2012.265 53 STF1904 15041+0530 7.1 7.3 347.5 9.88 2012.325 54 STF1916 15099+3859 8.3 10.5 331.0 9.88 2012.325 55 STF1921 15120+3840 8.5 8.7 282.4 30.61 2012.325 56 STT 292 15141+3147 6.0 9.2 157.6 118.50 2012.325 57 SHJ 195 15145-1826 6.7 8.3 139.9 46.91 2012.325 58 STT 138AB 15201+6023 7.6 7.7 195.2 152.08 2012.325 59 STT 138AC 15201+6023 7.6 9.2 162.2 90.36 2012.325 59 STF 28Aa-BC 15245+3723 4.3 7.0 170.9 108.13 2012.325 60

Table continues on next page.

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Divinus Lux Observatory Bulletin: Report # 27

NAME RA DEC MAGS PA SEP DATE N

BUP 162 15249+5858 3.3 8.7 49.5 253.79 2012.325 61 KU 108 15277+4253 7.5 9.6 318.9 40.49 2012.325 62 HJ 254AB 15303+1543 9.9 10.4 277.5 17.28 2012.328 63 STT 298AB-C 15360+3948 6.8 7.6 327.6 121.46 2012.328 64 ARY 10 15377+2329 8.5 9.3 315.4 79.49 2012.328 65 ARY 11 15383+2431 6.9 8.7 326.2 149.11 2012.328 66 ENG 54 15419-1941 4.7 10.3 282.6 169.85 2012.328 67 A 2230AC 15440+0231 5.9 9.0 207.7 193.55 2012.328 68 A 2230CE 15440+0231 9.0 7.2 235.3 172.81 2012.328 68 STF1973 15464+3627 7.6 8.7 321.2 30.61 2012.328 69 ENG 56AB 16160+1126 7.3 10.6 252.1 62.21 2012.383 70 HJ 225 16201-2003 7.4 8.1 332.8 46.91 2012.383 71 SHJ 226AB-C 16205-2007 7.6 8.3 20.1 12.84 2012.383 72 STF2051 16294+1036 7.6 9.3 18.9 13.83 2012.383 73 STF2079 16396+2300 7.5 8.1 90.5 16.79 2012.383 74 H 127 16436+0637 7.7 9.0 293.6 53.33 2012.383 75 GLP 12AC 16439-0032 10.1 10.1 300.3 105.66 2012.383 76 STF 2090AC 16449+0957 7.9 10.7 24.6 69.13 2012.383 77 STF 2090AD 16449+0957 7.9 10.1 27.9 90.36 2012.383 77 STF 2090CD 16449+0957 10.7 10.1# 38.4 21.73 2012.383 77 STT 585AB 16450+0605 6.6 10.3 190.7 162.94 2012.383 78 STT 585AC 16450+0605 6.6 10.7 252.5 129.36 2012.383 78 KPR 3AC 16458+3538 7.4 10.2 87.6 235.03 2012.383 79 SHJ 239AB 16458+0835 5.1 9.2 228.4 84.93 2012.383 80 ENG 58AB 16469+0215 6.7 8.8 217.3 149.11 2012.383 81 WAL 74AC 16487+3556 7.4 10.4 215.8 96.78 2012.383 82 STF 33AB 17037+1336 5.9 6.1 116.7 306.13 2012.402 83 STF 33Ab 17037+1336 5.9 10.3 137.8 177.75 2012.402 83 ARN 15AC 17037+1336 5.9 8.5 11.0 231.08 2012.402 83 HJ 264AE 17075+3557 10.5 5.4# 100.1 234.91 2012.402 84 STF2141 17166+0325 8.3 10.6 122.7 39.50 2012.402 85 SHJ 247 17208-1251 4.3 9.2 25.2 45.43 2012.402 86 S 687AB 17209+2430 5.1 9.3 56.1 223.18 2012.402 87 GUI 41AD 17209+2430 5.1 10.5 221.8 222.19 2012.402 87 STF2166 17279+1123 7.1 8.5 282.2 27.16 2012.402 88 ARY 13 17284+2950 8.6 8.9 89.0 102.70 2012.402 89

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Divinus Lux Observatory Bulletin: Report # 27

NAME RA DEC MAGS PA SEP DATE N

GUI 18AC 17287+1029 9.3 7.1# 18.5 189.60 2012.402 90 HJ 4964 17348-1115 5.5 9.8 224.7 54.81 2012.402 91 SHJ 251AB 17391+0202 6.2 7.7 327.7 111.59 2012.402 92 SHJ 251AC 17391+0202 6.2 10.7 14.8 133.31 2012.402 92 STF2191AB 17398-0458 7.8 8.4 266.8 26.17 2012.402 93 ENG 62 17425+2434 5.5 9.6 260.8 145.16 2012.402 94 STF2259 17590+3003 7.2 8.4 277.3 19.75 2012.402 95 STT 341AE 18058+2127 7.1 10.2 37.6 66.66 2012.437 96 STT 341AG 18058+2127 7.1 7.6 238.4 133.31 2012.437 96 ENG 63AB 18068+0853 7.0 10.5 246.4 129.36 2012.437 97 STF2291 18102+3402 10.4 10.7 339.6 29.63 2012.437 98 ROE 121AC 18132+1053 10.2 10.7 19.8 39.01 2012.437 99 SHJ 263AB 18179-1848 6.7 9.2 11.3 53.82 2012.437 100 BUP 181AC 18181+2318 6.5 10.0 125.3 154.05 2012.437 101 STF2317AD 18253+2605 7.7 10.2 189.6 44.44 2012.437 102 SCJ 17 18266+0632 8.3 10.6 351.7 51.35 2012.437 103 BU 1326AC 18267+2627 6.5 9.6 60.2 61.72 2012.437 104 GUI 21Aa 18267+2627 6.5 7.1 285.1 162.94 2012.437 104 STF2319AB 18277+1918 8.2 8.4 189.8 5.43 2012.437 105 STF2319AC 18277+1918 8.2 10.6 269.0 42.96 2012.437 105 STF2319AD 18277+1918 8.2 9.1 70.6 157.01 2012.437 105 BU 966AB 18319-1908 6.7 9.0 251.7 66.16 2012.440 106 BU 966AE 18319-1908 6.7 8.8 280.9 143.19 2012.440 106 BU 966AG 18319-1908 6.7 8.0 253.7 429.56 2012.440 106 BU 966AH 18319-1908 6.7 10.3 294.8 72.09 2012.440 106 BU 966AI 18319-1908 6.7 8.9 193.9 164.91 2012.440 106 BU 966BC 18319-1908 9.0 9.2 205.0 164.91 2012.440 106 BU 966BQ 18319-1908 9.0 10.5 199.1 109.61 2012.440 106 BU 966CD 18319-1908 9.2 10.5 170.8 11.36 2012.440 106 BU 966EF 18319-1908 8.8 9.6 290.2 25.18 2012.440 106 BU 966EK 18319-1908 8.8 9.7 26.3 30.61 2012.440 106 BU 966HJ 18319-1908 10.3 10.0# 310.0 44.44 2012.440 106 BU 966JM 18319-1908 10.0 10.3 344.8 70.61 2012.440 106 BU 966SE 18319-1908 8.1 8.8 141.7 131.34 2012.440 106 STT 171AB 18329+3850 6.9 8.0 327.6 150.10 2012.440 107 STF2348AB-C 18339+5221 5.4 8.6 271.2 25.68 2012.443 108

Table concludes on next page.

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Divinus Lux Observatory Bulletin: Report # 27

NAME RA DEC MAGS PA SEP DATE N

ARY 14AB 18340+4121 8.3 10.7 292.7 38.51 2012.443 109 ARY 14AC 18340+4121 8.3 9.3 345.7 118.50 2012.443 109 BU 50AC 18381+3935 9.5 10.4 327.8 72.58 2012.443 110 AG 225AB 18397+4035 10.2 10.3 354.6 6.42 2012.443 111 STF2355AC 18399+0722 6.3 10.5 38.3 109.61 2012.443 112 ARY 16 18407+0240 7.9 10.0 39.6 83.94 2012.443 113 STF2367AB-C 18413+3018 7.0 8.7 191.9 14.32 2012.443 114 H 36AC 18423-0903 4.7 10.6 130.4 51.84 2012.443 115 STF2380 18429+4456 7.2 8.6 8.1 25.68 2012.443 116 ENG 64AC 18470+1811 4.3 10.4 251.7 132.33 2012.443 117 STT 174 18479+1110 7.5 8.3 158.5 104.68 2012.443 118 H 3 18537+3658 5.6 9.8 19.5 175.78 2012.443 119 HJ 5504 18570+0228 7.6 10.7 305.6 68.63 2012.443 120

# Companion star is the brighter component. * Not listed in the WDS CATALOG.

Notes 1. 67 Ursa Majoris. AB=sep. dec. p.a. inc. AC=sep. & p.a. inc. Spect. A7, K0, K0,F5. 2. In Virgo. Position angle increasing. Spect. G0. 3. In Virgo. Sep. increasing; p.a. decreasing. Spect. K2. 4. In Ursa Major. Common proper motion; p.a. increasing. Spect. F8V, F9V. 5. In Virgo. Common proper motion. Sep. & p.a. decreasing. Spect. F5, F5. 6. In Virgo. Sep. & p.a. increasing. Spect. G0, G5. 7. In Virgo. Common proper motion. Sep. & p.a. decreasing. Spect. G5, G5. 8. Delta or 69 Ursa Majoris. Separation decreasing. Spect. A3V. 9. 12 Comae Berenicis. AC & AD = p.a. decreasing. Spect. F5, G, F8. 10. In Virgo. Common proper motion; sep. decreasing. Spect. K, K. 11. In Virgo. Sep. increasing; p.a. decreasing. Spect. K0, G5. 12. Alpha or 17 Comae Berenicis. Relfixed. Common proper motion. Spect. A0, A3. 13. In Canes Venatici. Sep. decreasing; p.a. increasing. Spect. F6V, A3. 14. In Virgo. Relatively fixed. Common proper motion. Spect. A5, F5. 15. In Coma Berenices. Common proper motion; p.a. decreasing. Spect. G0, F8. 16. In Virgo. Relatively fixed. Common proper motion. Spect. G5, K. 17. In Virgo. Sep. & p.a. increasing. Spect. F8, K2. 18. In Virgo. AB=sep. inc. AC=p.a. slightly inc. Spect. M0III, K0. 19. Chi or 26 Virginis. AB=sep. inc. AD=p.a. inc. Spect. K0, F0, K2. 20. In Virgo. Position angle decreasing. Spect. G2V. K. 21. 33 Virginis. Sep. decreasing; p.a. increasing. Spect. K1III, F5. 22. In Virgo. Sep. increasing; p.a. decreasing. Spect. A3V. 23. In Virgo. Sep. increasing; p.a. decreasing. Spect. G5V.

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Divinus Lux Observatory Bulletin: Report # 27

24. In Coma Berenices. AB=relfix; cpm. AC=sep. dec. Spect. A8IV, F2, G5. 25. In Corvus. Relatively fixed. Common proper motion. Spect. A0, F0. 26. In Virgo. Common proper motion. Sep. & p.a. dec. Spect. G8IV, G. 27. In Coma Berenices. Sep. decreasing; p.a. increasing. Spect. F5V. 28. In Coma Berenices. Common proper motion. Sep. & p.a. increasing. Spect. F8, F8. 29. In Virgo. Common proper motion. Sep. & p.a. decreasing. Spect. F5V, F9V. 30. In Virgo. Relatively fixed. Common proper motion. Spect. F8, F8. 31. In Virgo. Sep. increasing; p.a. decreasing. Spect. G3, K0. 32. In Ursa Major. CA=relfix, cpm. CE=sep. inc., cpm. Spect. A1V, F8, F2, F8. 33. In Canes Venatici. Common proper motion. Sep. & p.a. decreasing. 34. In Virgo. Relatively fixed. Common proper motion. Spect. F3II, F0. 35. In Canes Venatici. AB-C=sep. inc.; p.a. dec. AB-D=sep. dec. Spect. A6III, F5, G0. 36. In Canes Venatici. Relatively fixed. Common proper motion. Spect. G0, G0. 37. In Virgo. Relatively fixed. Common proper motion. Spect. K0, F8. 38. In Canes Venatici. Relatively fixed. Common proper motion. Spect. G5, K2. 39. In Bootes. AB=sep. inc. AC=relfix. Spect. F8, K2, G5. 40. In Bootes. Sep. & p.a. increasing. Spect. K0, K2. 41. In Ursa Major. Separation decreasing. Spect. K0. 42. In Virgo. Position angle increasing. Spect. K2III. 43. In Bootes. Relatively fixed. Common proper motion. Spect. F5. 44. In Bootes. Common proper motion; p.a. slightly increasing. Spect. A5V, A5. 45. In Bootes. Sep. increasing; p.a. decreasing. Spect. K4, K0. 46. Tau or 93 Virginis. Separation decreasing. Spect. A3V, K0. 47. In Bootes. Relatively fixed. Common proper motion. Spect. F2V, F8. 48. In Bootes. Relatively fixed. Common proper motion. Spect. A1V, A1V. 49. Sigma or 28 Bootis. Sep. decreasing; p.a. increasing. Spect. F2V. 50. In Virgo. Separation decreasing. Spect. F8, G5. 51. Alpha (9, 8) Librae. Relatively fixed. Common proper motion. Spect. A3IV, F4IV. 52. In Virgo. AB & AC = position angle increasing. Spect. K1III. 53. In Bootes. Relatively fixed. Common proper motion. Spect. F1V, F1V. 54. In Virgo. Common proper motion; sep. slightly decreasing. Spect. F0V, F0. 55. In Bootes. Common proper motion. Sep. dec.; p.a. inc. Spect. F7V, F8. 56. In Bootes. Relatively fixed. Common proper motion. Spect. A2, A2. 57. In Bootes. Sep. decreasing; p.a. increasing. Spect. K5, K5. 58. In Libra. Relatively fixed. Common proper motion. Spect. F3IV, F5. 59. In Draco. AB & AC = sep. increasing; p.a. decreasing. Spect. F0, F2, K2. 60. Mu or 51 Bootis. Relatively fixed. Common proper motion. Spect. F2IV, GoV. 61. Iota or 12 Draconis. Relatively fixed. Spect. K2III, K7. 62. In Bootes. Relatively fixed. Common proper motion. Spect. G5, K. 63. In Serpens. Relatively fixed. Common proper motion. Spect. G5. 64. In Bootes. Relatively fixed. Common proper motion. Spect. K3V, K0. 65. In Serpens. Common proper motion. Sep. slightly decreasing. Spect. K2, K0. 66. In Serpens. Separation decreasing. Spect. M4, G5.

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Divinus Lux Observatory Bulletin: Report # 27

67. Kappa or 43 Librae. Position angle increasing. Spect. M0III. 68. Psi or 23 Serpentis. AC = sep. dec. CE = p.a. inc. Spect. G3V, K2, K0. 69. In Corona Borealis. Common proper motion; p.a. decreasing. Spect. F5, G0. 70. In Hercules. Sep & p.a. decreasing. Spect. K0. 71. In Scorpius. Relatively fixed. Common proper motion. Spect. B9, B9. 72. In Scorpius. Relatively fixed. Common proper motion. Spect.A0, A. 73. In Hercules. Sep. & p.a decreasing. Spect. G5III, G5. 74. In Hercules. Common proper motion. Sep. slightly decreasing. Spect. F0, A5. 75. In Hercules. Position angle increasing. K0, F0. 76. In Ophiuchus. Separation increasing. Spect. G0. 77. In Hercules. AC = sep. inc. AD = p.a. dec. CD = sep. & p.a. dec. Spect. K7III. 78. In Hercules. AB = relfix, cpm. AC = sep. dec., p.a. inc. Spect. K0V, K3V, G0. 79. In Hercules. Position angle slightly increasing. Spect. F6V. 80. 43 Herculis. Separation increasing. Spect. K5III, K0. 81. In Ophiuchus. Position angle slightly decreasing. Spect. F0, B8. 82. In Hercules. Sep. & p.a. decreasing. Spect. F2. 83. In Hercules. AB=p.a. & sep. inc. Ab/AC=p.a. & sep. dec. Spect. A1V, K1III, G0. 84. In Hercules. Separation slightly decreasing. Spect. F8, A5. 85. In Ophiuchus. Sep. increasing; p.a. decreasing. Spect. F8. 86. Nu or 53 Serpentis. Sep. & p.a. decreasing. Spect. A2V. 87. 70 Herculis. AB = sep. inc. AD = sep. dec. Spect. A2V, F0. 88. In Ophiuchus. Relatively fixed. Common proper motion. Spect. A5V, A. 89. In Hercules. Sep. increasing; p.a. decreasing. Spect. A0, F8. 90. In Ophiuchus. Sep. increasing; p.a. decreasing. Spect. G5, A2. 91. In Serpens. Relatively fixed. Spect. B8V, F2. 92. In Ophiuchus. AB = relfix; cpm. AC = p.a. decreasing. Spect. K0, F0. 93. In Ophiuchus. Relatively fixed. Spect. F2V, F2. 94. 83 Herculis. Separation decreasing. Spect. K4III. 95. In Hercules. Sep. & p.a. increasing. Spect. G5II, A1V. 96. In Hercules. AE = sep. increasing. AG = sep. decreasing. Spect. G2V, F0. 97. In Ophiuchus. Position angle increasing. Spect. F5. 98. In Hercules. Separation increasing. Spect. A5, F8. 99. In Ophiuchus. Relatively fixed. Spect. A0, A2. 100. In Sagittarius. Position angle slightly decreasing. Spect. B8IV, B9V. 101. In Hercules. Separation decreasing. Spect. K5, F0. 102. In Hercules. Relatively fixed. Common proper motion. Spect. G7III. 103. In Aquila & NGC 6633 open cluster. Separation increasing. Spect. F5, A0. 104. In Hercules. AC & Aa = relatively fixed. Spect. B3V, A0, B3. 105. In Hercules. AB=sep. & p.a. dec., cpm. AC=p.a. dec. AD=p.a. inc. Spect. F5, F5. 106. In Sagittarius (M25 OC). AB=p.a. dec. AE=relfix. AG=sep. inc. Spect. A=G1.5I. 107. In Lyra. Sep. & p.a. increasing. Spect. F8, G5. 108. In Draco. Position angle slightly decreasing. Spect. G9III, F0. 109. In Lyra. AB = sep. dec. AC = sep. inc. Spect. AC = G5, F2.

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Divinus Lux Observatory Bulletin: Report # 27

110. In Lyra. Separation increasing. Spect. F. 111. In Lyra. Relatively fixed. Common proper motion. 112. In Ophiuchus. Sep. increasing; p.a. decreasing. Spect. G8III. 113. In Serpens. Sep. & p.a. increasing. Spect. F2, R0. 114. In Lyra. Common proper motion; p.a. slightly decreasing. Spect. G3IV, G5. 115. Delta Scuti. Sep. & p.a. decreasing. Spect. F2III. 116. In Lyra. Relatively fixed. Common proper motion. Spect. G8III, F2V. 117. 111 Herculis. Sep. increasing; p.a. decreasing. Spect. A5III. 118. In Aquila. Position angle decreasing. Spect. B9, B9. 119. Delta or 1 Lyrae. Separation slightly increasing. Spect. B2.5V, K. 120. In Serpens. Separation increasing. Spect. F8, A2.

Vol. 9 No. 1 January 1, 2013 Journal of Double Star Observations Page 19

Using VizieR to Measure Neglected Double Stars

Richard Harshaw

Cave Creek, Arizona [email protected]

Abstract: The VizierR service of the Centres de Donnes Astronomiques de Strasbourg (France) offers amateur astronomers a treasure trove of resources, including access to the most current version of the Washington Double Star Catalog (WDS) and links to tens of thousands of digitized sky survey plates. These plates allow the amateur to make accurate measurements of position angle and separation for many neglected pairs that fall within reasonable tolerances for the use of Aladin, the digitized sky survey add-in called by VizieR. This paper presents 221 measurements of 102 neglected pairs from the WDS.

As I sit at my keyboard in Cave Creek, Arizona VizieR service. To access the VizieR site, use this this July afternoon, it is the start of monsoon season URL: http://cdsarc.u-strasbg.fr/viz-bin/VizieR. in Arizona—a time of frequent clouds, wind, and VizieR’s home screen is shown in Figure 1. Note short but severe thunderstorms. When you combine the “Catalog Call Window” highlighted in Figure 1. the atmospheric conditions with the oppressive sum- This is where you can call up any of 10,178 catalogs, mer heat of the desert, you see why amateur astron- ranging from deep sky objects to double stars to or- omy in Arizona more or less goes on vacation during bital catalogs to spectroscopy, and much, much more. the summer! This is a good time of year, then, for me To call up the WDS (which is updated nightly), enter to do my astronomy with my computer. this in the call window: A tool I have found and grown quite fond of for double star research is the VizieR service of the Cen- b/wds/wds tres de Donnes Astronomiques de Strassbourg (France). This portal can take the amateur to over Then click “Find”. This will call the WDS query form. 8,000 on-line catalogs (some obsolete and of histori- It is shown in Figure 2. Before you start asking for cal value only), and others as fresh as last week. Of WDS data, you may want to scroll down the screen particular interest to me are the daily-updated until you see the four lines for proper motion. (They Washington Double Star Catalog (WDS) and its links are labeled “pmRA1”, “pmDE1”, “pmRA2” and to the Aladin applet within VizieR, an applet that “pmDE2”.) I always check these so I can also see the calls any of dozens of different digitized sky survey proper motion on a pair (when that data is available plates of the coordinates in question in a variety of - most of the time it is not). The proper motion data formats and wavelengths. As you will see in this pa- can help you find a pair that is moving rapidly across per, VizieR gives the amateur double star observer the field from plate epoch to plate epoch. the power of a professional grade telescope and the tools to actually do serious and useful science. The Value of Photography in Double Star Research Navigating Your Way Around VizieR William Hartkopf and Brian Mason, chief cura- Let’s begin with a brief tutorial on how to use the (Continued on page 21)

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Using VizieR to Measure Neglected Double Stars

Figure 1: VizieR Home Page with Catalog call window highlighted

Figure 2: The WDS input form showing the WDS identifier input window

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Using VizieR to Measure Neglected Double Stars

(Continued from page 19) objective than visual measurement, this finding tors of the WDS and eminent double star astronomers seems reasonable.” The graphs he publishes on the in their own right, have published a superb mono- web page clearly show the superiority of photographic graph on the web site for the 6th Orbital Catalog measurements. (called at this URL: http://ad.usno.navy.mil/wds/ The down side is that photographic measure- orb6.html). Hartkopf did extensive research on the ments are difficult if not impossible for extremely quality of measurement methods as it is imperative close pairs or pairs with wide ranges in magnitude. that when one derives an orbit that the input data for the solution is carefully weighed for its reliability, Calling A Double Star and the method of making the measurements is al- Let me illustrate how to pull data for a double most as important as the skill of the astronomer mak- star by showing you the steps I would use to check on ing those measurements. WDS 05316+6310 (STI 567 in common parlance). I In the section on grading orbits, Hartkopf writes call this data by typing 05316+6310 into the WDS (http://ad.usno.navy.mil/wds/orb6/ identifier window and clicking “Submit”. This action orb6text.html#grading) that visual observers (those calls the first data screen, see Figure 3. Depending using such devices as micrometers or reticules like on your screen resolution, this image may be a bit the Celestron MicroGuide or Meade Astrometric eye- difficult to read, so Figure 4 is a blown up version of piece) “received a wide range in relative weight” the vital data. whereas “Photographic observers were of fairly uni- I did not show the proper motion data as we only form quality.” Hartkopf went on to say, “Since photo- have data for the primary, and it is modest (12 mil- graphic techniques are presumably somewhat more liarcseconds [mas] a year east in RA and 19 mas a year south in declination).

Figure 3: The WDS data screen showing the link to the Digitized Sky Survey plate applet

Figure 4: Enlargement of the WDS data

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Using VizieR to Measure Neglected Double Stars

We note that the last measure on file with the the plate name (“DSS2.F.POSSII” on the right side of WDS was made in 1908 and it recorded a value of the image pane). Once that tag is highlighted by blue- 156° for θ and 10.60” for ρ. The stars, with magni- gray shading, I can get the plate data by clicking on tudes in the mid-12’s, should show up as nice discs on the “prop” icon, shown in Figure 6. When I do, this the digitized sky survey plate. information window appears, Figure 7. We want to measure this pair for the most recent Just below the “Get original header” button, I see data available, and for that we will need to pull up the plate epoch (1989.976). To learn more about this the digitized sky survey (DSS) plate for this position. plate and the telescope that made it, I click the “Get We do that by clicking the hyperlink “Optical Image original header” button and see a long dialog box ap- of this region with Aladin-Java.” The result of click- pear (you’ll need to scroll it to see all of it). Here is the ing on the hyperlink is shown in Figure 5. section where the telescope data can be found, Figure There is a tremendous amount of work you can do 8. with this amazing little applet. First, we want to know the epoch of the plate. To do that, I will click on

Figure 7: The Properties dialog box

Figure 5: The DSS image of the region showing the DSS plate used

Figure 6: Click the "prop" icon after selecting the plate Figure 8: The properties dialog showing the telescope used for the plate

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Using VizieR to Measure Neglected Double Stars

I make a note of the epoch and telescope and close On the right side of the image is a column of tool the dialog boxes, returning to the raw plate pane. icons that you will find very helpful. One of them is As you can see from the plate, the images of the the ZOOM icon, Figure 9. stars are pretty close together, so making an accurate When I click the mouse, the shaded area expands measurement will be difficult— unless I let Aladin do to fill the plate pane as shown in Figure 10. all the heavy lifting! This is better, but still not good enough. I want to

Figure 9: After clicking the ZOOM tool, the zoom target selection window appears; center it on the star to measure and click the mouse

Figure 10: The target after one zoom operation

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Using VizieR to Measure Neglected Double Stars

keep repeating the ZOOM steps until I get an image are, cover several pixels on the plate. of the pair to measure that nearly fills the pane. Af- Here is where the next handy tool comes into ter four zooms, I get the image shown in Figure 11. play. I use it by first clicking on the “DSS2.F.POSSII” This is much better! label at the lower right of the window, then click the But now I need to pinpoint the centers of the im- “pixel” tool. Figure 12 is a close-up. ages, and as you can tell, the stars, as faint as they This action calls the Pixel dialog, and it is shown

Figure 11: The target after 4 zoom operations.

Figure 12: Selecting the PIXEL tool

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Using VizieR to Measure Neglected Double Stars

in Figure 13. This option takes most of the background noise You can use the mouse and drag a point along the out and leaves me with two images for which it will diagonal line to change the pixilation of the image, be easier to find the centers. but I prefer to use the Pow2 option (the last one of the Finding the center of a photographic image is not radio buttons). Selecting Pow2 gives the result shown easy, but the enlargement and Pow2 tools make it in Figure 14. easier. For dim stars, like these, you will have to select the center axes for both vertical and horizontal, and where they intersect should be the center (or at least within a pixel of it). For brighter pairs, the diffraction pattern induced by the Schmidt plate holder will result in four spikes radiating outward from the star image centers. It is easier in such a case to merely use the diffraction spikes as guides to the center. What I want to do is mark the centers so I can measure them repeatedly and improve accuracy. Here is where the next handy tool in Aladin comes into play: the “draw” tool. By clicking “draw”, you can use the mouse to find a point on the image then click it to anchor the line. Click the next point you want to include in the drawing, and Aladin will automatically draw a line from the starting point to your new point. Then move the mouse to the other axis and repeat the procedure. To keep the image cleaner, I usually break the draw command after marking one star (by clicking the Figure 13: The Pixel adjustment dialog box and tool “select” tool at the top of the pane) and then clicking “draw” again and drawing the other star’s axis mark- ers. Figure 15 is what my drawing produced. (I have

Figure 14: The image after Pow2 is applied Figure 15: The star centers have been marked with the "draw" tool

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Using VizieR to Measure Neglected Double Stars

also used the “properties” tool for drawings, called by pressing ALT + ENTER at the same time, to make the drawing lines red instead of their default blue. The blue lines get hard to read on the dark back- grounds.) I next use the “dist” tool (fourth from the top) and measure the distance and separation between the marked star centers, but first, I want to ZOOM the image one more time (if the frame will contain it) to get the star centers as far apart as the frame will allow to maximize measurement accuracy. Figure 16 is the result, ready for measurement. It is a much easier image to work with than the original DSS plate image. I will then click the “dist” tool and place the mouse over the primary’s center and click it, then drag the mouse to the secondary’s center and click it again. When I do, Aladin measures the distance (in seconds) and the position angle for me automatically Figure 16: Final zoom and ready for measurement and displays the results in a small window at the bot- tom of the pane as shown in Figure 17.

Figure 17: A measurement of high accuracy

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Using VizieR to Measure Neglected Double Stars

Note that Aladin displays 11.62” for ρ and 154.9° for θ. Not bad, and I did not even have to stay up late to get this result! I then record the values for ρ and θ, then use the mouse to drag the measurement arrow aside. I then click “dist” again and repeat the measurement, this time starting at the secondary and moving to the primary, and adding 180° to the measurement for θ. I again note the values for ρ and θ, then drag the arrow aside, and repeat this process six times, alternating the starting point from the primary to the secondary for each measurement. When finished, I will have six measurements and arrows that should be virtually parallel and of the same length as in Figure 18. This has already been a powerful tool and easy to use. With practice and skill, you can probably call a WDS pair and do a set of six measurements in fewer than 8 minutes. But wait - there’s more! We have only measured one of about 15 DSS Figure 18: Six measurements in the bag! plates available to us for this region. To see what else we could call and measure, we need to ask Aladin to show us what it has up its sleeve. Figure 19 illustrates how that is done. By clicking the file folder icon at the upper left of the Aladin window, a dialog for plate selection appears, which is shown in Figure 20. The default is to use the Aladin images (the highlighted tab on the left). By clicking “Submit”, Aladin looks at its records and reports back to you what plates you can pull up to review as shown in Figure 21.

Figure 19: Call other DSS plates with this icon

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Using VizieR to Measure Neglected Double Stars

would do—the fourth one in the list (POSS I O plate). By clicking on that line, I can then load that plate too and repeat the epoch discovery and make the measurements I did for the POSS II plate. And so on, and so on. But it gets even better! The Aladin pane has a command menu at the top, with a very important command option. It is the Image command and it has the menu shown in Figure 22. The blink comparator is a valuable tool in double star research, especially when you are trying to find a pair that has not been measured in over 100 years and an examination of the first plate called does not show anything obvious. Often, by calling earlier (and later) plates, and then setting up a blink sequence, the pair you seek becomes obvious as the companion Figure 20: Opening dialog to call other plates moves relative to the primary and extrapolation of the motion back to the last measurement epoch shows that you have the right pair.

I have widened the results window so you can see Limitations of Aladin the Date column for each plate. The trick is to select a While Aladin is an awesome tool for the double plate from a different epoch (at least 10 years if possi- star astronomer, it does have its limitations. ble) and of the same general scale. The POSS II plate First, a really bright primary (and here, anything we started with was about 11 minutes square, so use brighter than 5th magnitude is blinding) will produce the Size column to find a plate of about the same di- a huge image on the plates— really bright stars like mensions. In this example, I find a POSS I plate that Sirius burn out almost the entire 11 minute plate! Anything close by (like the Pup) will be totally invisi-

Figure 21: A list of other DSS plates to view

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Using VizieR to Measure Neglected Double Stars

The results of this query were exported to a new spreadsheet which was used for the research for this paper. A total of 4,642 pairs were thus chosen. Methodology I then began (on cloudy or super-hot nights) to use VizieR and check each pair on the list. In most cases, the Aladin image was not of good enough quality for a measurement, so the pair was removed from the list. In other cases, the pair could not be identified on any plate (this is often the case with the faint pairs found in the 1880’s-1920’s by such astronomers as Scheiner, Stein, Baillaud, and others). Where the Aladin plate showed a usable image, the pair was measured six times as described above and the results entered into the spreadsheet. The spreadsheet then computed the average val- Figure 22: How to call up the blink comparator ues for r and q and compared them to the last measures on record. Yearly changes in separation (in mas ble in the glare of the primary. So if you have a bright per year) and position angle were then computed (but primary, you need a very wide separation to have any not shown in the table below). In general, if the yearly chance of pulling the companion out of the back- changes among the measures are on the same order of ground overburn of the image. magnitude, the results are probably reliable. If they Second, pairs closer than 10 seconds will be diffi- vary widely, there may be issues at play. For in- cult to measure accurately, even with high zoom fac- stance, operator error is one possibility; also, if a pair tors and pixel adjustments. has passed periastron or apastron between two meas- Third, some plates (especially the older ones) used urements, we would expect to see sign reversals in older emulsions which required longer exposure times the change computations. Even if the stars have not which resulted in larger star images and “fuzzier” yet reached periastron but are merely approaching it, pixilation. Try to use the cleanest plate(s) you can rapid changes in the rate of change of the separation retrieve. or position angle could be the result of the compan- Fourth, to take maximum advantage of VizieR for ion’s acceleration as it approaches periastron. Where photographic analysis of doubles, you need as large a changes in the rate of change appear, I will call atten- screen as you can afford for your computer (mine has tion to that fact in the Notes column. a 68 cm diagonal) and a mouse with as high a resolu- Finally, to assist orbit computers of the future in tion as you can afford. Small screens or low-resolution grading the quality of each measurement, I added a 5- screens and mice will result in rather poor results. step subjective scale for the plate quality, ranging from Excellent (crisp images, little back ground noise) Criteria for Selecting the Pairs in This to Very Poor (fuzzy images, bloated stars, merging of Paper star images, background noise, etc.). I began by going to the WDS home page (http:// The Results ad.usno.navy.mil/proj/WDS/wds.html) and download- ing the latest TXT version of the WDS; importing it The results of 102 pairs studied in the first six into Excel, and after appropriate formatting, ran a hour angles of right ascension are given in the table query using the multiple filter option in Excel. The on the following pages. Codes are as follows: filter let pass only those stars that met the following Telescope: 1 = 48-inch; 2 = 1.3 meter criteria: Plate Series: 1 = POSS I; 2 = POSS II; 3 = 2 MASS; 4 • No measurements made after 1990 = SERC; 5 = MAMA; 6 = SERC/MAMA • No pairs closer than 10” as of the last meas- Plate Quality: 1 = Excellent; 2 = Good; 3 = Medium; 4 urement = Poor; 5 = Very Poor

• No more than 12 measurements on record (Continued on page 36)

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Using VizieR to Measure Neglected Double Stars

Plate Plate WDS CODE ID Yr 2 Sep 2 PA 2 Epoch Tel ρ θ Notes Avg Avg Series Qual 00057+4549 STT 547 BP 1989 18.8 54 1998.841 2 15.61 20.6 3 00529-1858 SLE 125 1982 30.8 144 1999.669 Unk 30.66 143.9 4 01032+2716 HO 494 1907 13.1 95 1953.779 1 13.33 90.0 1 1990.808 1 13.52 88.2 2 01034+2705 HO 495 1924 12.2 247 1953.779 1 10.96 246.4 1 1990.808 1 9.38 244.5 2 01047+3854 A 1514 AC 1930 22.1 263 1986.904 1 21.19 262.5 2 01058+0455 STF 90 AD 1910 31.8 313 1953.831 1 36.42 319.1 1 1995.726 1 39.42 321.7 2 01061-4643 HJ 3417 AB-C 1927 57.9 52 1989.748 1 63.23 54.8 5 1999.712 2 65.18 54.7 3 01074+3400 HO 308 1904 19.1 256 1951.835 1 19.07 255.8 1 1991.753 1 18.96 254.7 2 01077+1651 J 926 AC 1952 26.5 280 1954.759 1 28.81 288.0 1 1990.961 1 29.25 288.7 2

01083+5455 BUP 14 AE 1907 87.7 145 1954.006 1 93.93 112.3 1 1 1989.641 1 38.79 303.1 5 01083+5455 STT 551 AF 1854 53.2 328 1954.006 1 44.21 307.9 1 2 1989.641 1 178.30 298.5 2 01084+0539 BUP 15 AB 1907 86.1 286 1954.677 1 75.85 296.4 1 1995.726 1 70.36 305.5 2 01235+6102 STI 209 1901 11.1 75 1954.751 1 21.47 71.1 1 1989.676 1 28.15 69.2 2 01256+3133 STT 30 AD 1922 24.7 167 1949.970 1 22.21 175.6 1 1991.759 1 20.56 192.8 2 01274+0658 PLQ 48 AB-C 1924 62.5 41 1954.677 1 59.88 36.9 1 1987.647 1 58.55 31.9 2 01277+4524 BU 82 AD 1907 125.5 111 1953.708 1 111.68 112.5 1 1989.752 1 99.26 113.2 2 01348+6035 STI 235 1909 11.1 306 1989.676 1 9.61 311.6 5 01385+6042 STI 248 1902 12.5 19 1954.751 1 11.78 18.6 1 1989.676 1 11.76 18.6 2 01397+5711 STI1649 1917 13.5 114 1954.006 1 13.53 110.2 1 1989.916 1 13.37 109.6 2 01422-1753 BUP 24 1911 85.4 292 1978.689 Unk 120.10 284.8 4 1988.945 1 125.45 284.0 5 01426+6033 BU 1363 AB 1912 12.7 101 1954.751 1 13.73 99.7 1 4 1989.962 1 13.64 92.7 2 3

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Using VizieR to Measure Neglected Double Stars

Plate Plate WDS CODE ID Yr 2 Sep 2 PA 2 Epoch Tel ρ θ Notes Avg Avg Series Qual 01447+5603 STI1673 1917 11.8 60 1954.754 1 13.48 64.5 1 3 1989.916 1 13.33 65.6 2 2 1999.032 2 13.11 66.5 3 3 01468-6447 HJ 3468 1916 20 20 1975.596 Unk 24.83 17.2 4 2 1989.769 1 24.84 15.1 2 2 1999.865 2 24.75 15.6 3 1 01473+5801 STI1684 1911 14.3 309 1954.751 1 14.87 308.6 1 4 1989.962 1 14.67 304.8 2 3 1999.909 2 15.58 305.7 3 2 01522-4343 HJ 3471 1916 70.2 47 1977.619 Unk 104.14 48.3 4 1 1988.934 1 110.86 48.2 5 1 1999.750 2 116.89 48.5 3 1 01523+5703 STI1702 1911 11.4 151 1954.754 1 9.13 158.6 1 3 1989.916 1 8.57 161.9 2 2 1999.909 2 8.50 159.4 3 4 01533+4044 HJ 1094 1913 59.6 5 1953.708 1 59.47 356.4 1 3 1989.768 1 59.29 359.1 2 2 01536+3623 ALI 29 1932 12.1 117 1954.735 1 12.05 111.1 1 3 1989.918 1 12.57 112.5 2 2 1997.858 2 12.61 109.9 3 1 01572+5716 STI1728 1911 14.4 96 1954.754 1 14.59 98.7 1 2 1990.861 1 14.19 95.7 2 1 1999.909 2 14.07 96.3 3 1 01576+3134 BAR 21 BC 1915 20.2 259 1951.841 1 21.49 236.4 1 2 1991.707 1 20.57 241.0 2 2 01591+3313 BUP 28 AC 1934 91.2 26 1951.841 1 94.90 21.3 1 4 1989.918 1 103.82 14.6 2 1 1999.844 2 106.41 13.2 3 1 01598+5715 STI1748 1911 11.6 46 1954.754 1 11.91 47.5 1 3 1990.861 1 11.76 47.5 2 3 02019+2415 POU 157 1898 16.9 182 1953.867 1 15.92 179.0 1 4 1991.770 1 15.71 178.1 2 3 02020+7054 BU 513 AD 1959 51.1 85 1954.738 1 50.42 84.8 1 3 1991.682 1 52.42 81.8 2 3 1999.748 2 53.02 86.4 3 2 02022+1120 J 1080 AC 1915 10 300 1950.614 1 15.08 306.1 1 2 3 1991.685 1 15.27 311.8 2 1 1997.740 2 14.92 312.0 3 1

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Using VizieR to Measure Neglected Double Stars

Plate Plate WDS CODE ID Yr 2 Sep 2 PA 2 Epoch Tel ρ θ Notes Avg Avg Series Qual 02043-3616 HJ 3480 1960 26.2 93 1978.886 Unk 27.90 89.5 4 1 1990.654 1 29.20 88.7 5 1 1999.597 2 30.38 88.0 3 1 02055+7607 BU 785 AC 1959 28.5 128 1993.640 48 in 27.45 125.8 2 3 02128-0224 STF 231 AC 1908 172.7 61 1954.893 1 157.84 57.6 1 2 1993.845 1 147.33 53.8 2 2 02135+5926 STI 351 1910 12 165 1952.706 1 10.23 166.4 1 3 1989.962 1 9.45 169.3 2 1 1999.712 2 9.07 169.8 3 2 02171+3413 DOR 66 AB 1907 65.4 337 1951.835 1 103.26 313.5 1 2 1986.904 1 140.26 304.3 2 2 02181+5637 STI1835 1914 10.8 156 1954.754 1 12.28 154.7 1 2 4 1990.861 1 12.71 155.3 2 2 1999.781 2 12.00 156.1 3 3 02193-0259 BU 1371 AB 1911 73.1 85 1954.902 1 72.55 78.1 1 3 1994.665 1 72.44 73.6 2 3 02228+4124 BUP 30 AB 1917 56.3 2 1953.998 1 59.89 4.5 1 3 1987.797 1 63.04 6.6 2 1 1998.773 2 64.44 6.9 3 1 02233+1525 AG 38 AC 1925 129.3 181 1954.967 1 136.01 183.3 1 1 1990.781 48 in 143.11 185.4 2 1 1997.708 2 145.14 185.7 3 1 02257+6206 WYN 1 AC 1972 46 240 1952.706 1 43.62 245.8 1 1 1989.965 48 in 44.05 246.5 2 1 1999.011 2 43.86 246.5 3 3 02257+6206 WYN 1 AD 1972 88 273 1952.706 1 93.26 258.1 1 1 5 1989.965 48 in 93.81 258.4 2 1 1999.011 2 92.98 258.6 3 3 02257+6206 WYN 1 AE 1972 31 220 1952.706 1 35.20 220.6 1 1 1989.965 1 34.43 221.4 2 1 1999.011 2 34.36 220.8 3 3 02257+6206 WYN 1 AF 1972 33 208 1952.706 1 31.22 188.1 1 1 1989.965 1 31.12 188.5 2 1 1999.011 2 31.06 188.5 3 3 02257+6206 WYN 1 AG 1972 42 213 1952.706 1 44.04 208.3 1 4 1989.965 1 43.45 208.6 2 4 1999.011 2 44.09 209.0 3 3

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Using VizieR to Measure Neglected Double Stars

Plate Plate WDS CODE ID Yr 2 Sep 2 PA 2 Epoch Tel ρ θ Notes Avg Avg Series Qual 02308+5533 STF 270 AD 1927 42.4 272 1957.965 1 45.87 274.9 1 2 1990.861 1 47.99 278.9 2 2 1999.947 2 49.60 279.6 3 3 02308+5557 STI1903 1918 13.9 271 1957.965 1 14.60 272.1 1 2 6 1990.861 1 13.75 272.6 2 2 02325+5809 STI1907 1911 14.7 155 1952.706 1 13.32 159.1 1 2 1990.861 1 12.31 160.5 2 2 1999.947 2 11.68 158.6 3 2 02383+5846 STI1920 1914 13 151 1952.706 1 12.97 125.8 1 2 1989.965 1 12.94 128.9 2 2 1997.771 2 13.15 127.4 3 2 02414+0426 A 2337 AD 1926 25.4 205 1954.970 1 23.31 208.0 1 3 1990.729 1 21.29 210.4 2 1 1997.667 2 21.03 210.4 3 1 02431+5526 STI1928 1911 10.6 231 1957.965 1 11.64 232.4 1 2 7 1993.940 1 11.53 234.5 2 2 02559+6131 BUP 36 AB 1925 52.6 256 1954.072 1 51.41 256.7 1 2 8 1993.943 1 62.03 256.6 2 1 02564+3716 ES 2146 AC 1980 12 71 1954.970 1 9.79 76.6 1 3 1988.712 1 8.89 91.0 2 4 1998.893 2 8.93 95.2 3 2 02566+4710 STF 324 1934 24.9 205 1953.769 1 25.18 204.0 1 2 9 1989.749 1 24.24 204.5 2 3 1998.899 2 25.27 203.1 3 3 02595+3753 HO 219 AD 1929 52.9 184 1954.970 1 51.52 186.1 1 2 1989.746 1 50.47 187.0 2 2 1998.790 2 49.90 187.1 3 2 03014+5955 STI 419 1910 14.2 152 1954.072 1 12.42 156.2 1 3 1993.943 1 10.57 159.3 2 2 03088+2339 POU 247 1897 16.6 155 1954.891 1 14.66 147.9 1 2 1989.976 1 13.96 143.5 2 2 1998.751 2 13.75 142.8 3 1 03124+4744 BLL 11 AB 1963 11.6 348 1953.769 1 12.73 347.8 1 4 1989.763 1 14.45 338.8 2 4 1998.850 2 14.68 339.7 3 5 03124+4744 BUP 40 AC 1963 23.6 187 1953.769 1 24.02 185.7 1 4 1989.763 1 21.22 190.7 2 4 1998.850 2 19.94 193.2 3 4

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Using VizieR to Measure Neglected Double Stars

Plate Plate WDS CODE ID Yr 2 Sep 2 PA 2 Epoch Tel ρ θ Notes Avg Avg Series Qual 03173+5809 STI1971 1978 15.5 288 1993.943 1 15.36 289.0 2 2 03183+5157 HJ 2180 1909 19.1 271 1954.738 1 26.15 287.4 1 2 1989.766 1 30.89 292.3 2 2 03245+3332 BU 1377 AC 1963 26.6 180 1992.974 1 25.68 183.3 2 2 03449+2407 HL 7 AD 1886 231.2 191 1951.909 1 217.50 193.5 1 5 1989.957 1 216.60 192.8 2 2 03562+5939 BUP 48 AF 1925 37.6 75 1954.012 1 42.69 85.2 1 2 1992.832 1 53.18 91.7 2 2 04204+3434 BU 1382 1913 110 313 1955.808 1 92.95 337.8 1 2 10 1989.826 1 92.83 338.2 2 2 04215-0006 HO 329 AB 1909 35.8 64 1955.953 1 39.27 56.3 1 2 1991.031 1 42.82 52.8 2 2 04286+1911 BUP 61 AB 1909 181.7 268 1955.939 1 184.76 268.9 1 2 1991.775 1 188.31 268.8 2 1 04368-6205 HJ 3679 AB 1963 38.4 13 1983.051 1 38.99 14.6 6 2 04368-6205 HJ 3679 AC 1963 34.5 124 1983.051 1 35.10 120.1 6 2 04373+5550 STI2058 1912 11.2 332 1953.769 1 9.93 334.1 1 3 1990.817 1 8.55 329.4 2 3 04429+5532 STI2066 1914 11.3 9 1953.769 1 12.16 4.2 1 2 1990.817 1 13.56 0.2 2 2 04447+6239 STI 536 1908 11 282 1953.113 1 12.46 291.9 1 3 1993.938 1 12.75 292.1 2 2 04488+7556 BU 1388 1913 96.9 60 1955.036 1 94.59 49.8 1 3 11 1996.933 1 97.17 47.0 2 2 04517+4550 BUP 71 1925 95.9 82 1953.771 1 89.45 71.3 1 3 1989.763 1 85.76 56.1 2 2 04543+0722 STF 612 AC 1927 46.7 236 1954.080 1 49.26 247.6 1 4 1990.809 1 55.88 257.8 2 3 04549+1009 BUP 72 AC 1962 39.7 359 1990.058 1 42.45 358.1 2 2 04558+5637 STI2077 1912 12.5 67 1953.769 1 12.93 64.9 1 2 1989.900 1 12.92 63.9 2 2 04564+4739 ES 57 AC 1907 16.5 61 1953.771 1 17.80 59.3 1 2 1996.725 1 17.56 59.6 2 2 05021+6910 BU 313 AD 1898 43 179 1953.785 1 39.93 188.1 1 4 1994.831 1 37.38 193.4 2 2 05061+6232 STI 549 1908 10.2 310 1954.165 1 13.23 311.1 1 3 1989.971 1 13.49 312.5 2 2 05067+5136 BU 1046 AE 1922 131.6 348 1954.970 1 135.65 349.4 1 4 1996.725 1 143.04 351.3 2 2

Table concludes on next page.

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Plate Plate WDS CODE ID Yr 2 Sep 2 PA 2 Epoch Tel ρ θ Notes Avg Avg Series Qual 05090+2505 POU 562 AB 1951 11.4 116 1951.983 1 8.39 126.1 1 4 1988.949 1 6.82 103.6 2 4 05092+2428 POU 564 1951 13.3 131 1951.983 1 10.15 134.2 1 4 1988.949 1 9.26 133.1 2 3 05114+5440 STI2087 1922 13.1 107 1954.970 1 11.27 111.3 1 3 1989.900 1 9.76 111.0 2 2 05143+3617 SEI 113 AB 1982 23.1 110 1954.992 1 29.12 121.0 1 2 1988.917 1 28.91 121.5 2 2 05225+4621 ES 1231 AC 1913 14.1 9 1950.935 1 15.59 13.7 1 3 1989.386 1 17.59 15.0 2 2 05237+3652 SEI 231 1895 13.3 173 1954.992 1 14.36 173.7 1 2 1988.917 1 14.20 174.1 2 2 05247+3723 BU 888 AC 1914 27.4 331 1954.992 1 27.62 332.0 1 3 1988.917 1 28.07 333.5 2 4 05316+6310 STI 567 1908 10.6 156 1954.754 1 11.67 155.6 1 3 1989.976 1 12.13 154.4 2 2 05347+2346 POU 733 1951 15.2 84 1990.787 1 14.34 84.3 2 2 05382+2429 POU 764 1951 19.2 55 1990.787 1 19.07 54.6 2 2 05410+3913 ALI1057 1929 14 314 1953.026 1 13.92 314.4 1 3 1989.766 1 13.59 312.7 2 2 05446+6320 STI 579 1908 11.1 127 1954.754 1 9.74 129.5 1 3 1996.791 1 8.52 127.1 2 4 05456-1503 BUP 83 AD 1908 27 228 1955.115 1 29.35 243.9 1 4 1997.005 Unk 32.38 253.6 4 2 05463+2423 POU 771 1951 13.3 11 1951.849 1 11.18 14.6 1 3 1992.062 1 10.40 10.2 2 2 05492+3911 BU 192 AB 1928 39.3 356 1989.766 1 41.06 357.8 2 3 05524+5450 STI2113 1914 14.4 39 1953.114 1 13.39 41.0 1 3 1990.061 1 12.25 42.5 2 2 05536+2423 POU 807 1951 16 350 1951.849 1 15.44 349.3 1 3 1992.062 1 15.29 347.6 2 2

Notes: 1. BUP 14 AE: annual rate of change from 1907 to 1954 was +132.5 mas r and -0.7° q; from 1954 to 1989 it was -1547.3 mas r and +5.4° q. Could this pair have had periastron between 1954 and 1989? 2. STT 551 AF: annual rate of change from 1854 to 1954 was -89.9 mas r and -0.2° q; from 1954 to 1989, it was +3762.8 mas r and -0.3° q. Did this pair pass through periastron during the 1954-89 window? 3. J 1080 AC: the annual rate of change between 1950 and 1991 was +4.5 mas and 0.1°, but between 1991 and 1998 it flipped to -56.5 mas and 0.0°. The 1998 data was from a 2 MASS plate; several anomalous pairs in this project showed that pattern with 2 MASS data. I believe there may be a systematic error with how Ala- din orients 2 MASS plates with regards to celestial north and have sent a note to Centres de Donnes Astro- nomiques de Strassbourg, but have yet to receive a reply. 4. STI 1835: annual rate of change from 1954 to 1990 was +11.8 mas / 0.0°; from 1990 to 1999 (a 2 MASS plate again), it flipped to -79.8 mas / 0.1°. 1999 was from a 2 MASS plate.

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Using VizieR to Measure Neglected Double Stars

5. WYN 1 AD: The 1952-1989 rate of change was +14.8 mas / 0.0°, but from 1989 to 1999 it flipped to -91.8 mas / 0.0°. 1999 was from a 2 MASS plate. 6. STI 1903: A flip in the rate of change occurred between the 1918-1957 era (+17.4 mas / 0.0°) and the 1958- 1990 era (-25.7 mas / 0.0°). 7. STI 1928: The rate of change from 1911 to 1957 was +22.2 mas / 0.0° per year; between 1957 and 1993 it switched to -3.1 mas / 0.1°. 8. BUP 36 AB: Between 1925 and 1954, rate of change was -40.8 mas / 0.0° per year; from 1954 to 1993, it jumped to +266.3 mas / 0.0°. 9. STF 324: The rate of change from 1953 to 1989 was -26.1 mas / 0.0°; between 1989 and 1998, it was +112.4 mas / -0.2°. Another 2 MASS case for the 1998 plate. 10. BU 1382: From 1913 to 1955, the rate of change was -398.3 mas / +0.6°; from 1955 to 1989, it dropped to - 3.5 mas / 0.0°. 11. BU 1388: The 1913-1955 rate of change averaged -55.0 mas / -0.2° per year; from 1955 to 1996, it was +61.6 mas / -0.1° per year.

(Continued from page 29) Acknowledgements The author wishes to recognize the following as Recommendations for Further Re- sources for material for this paper: search Hartkopf, William I. and Mason, Brian D., The Sixth Catalog of Orbits of Visual Binary Stars; http:// Any amateur with a high resolution monitor and ad.usno.navy.mil/wds/orb6.html; July 2012. mouse and fairly fast internet download speeds The Washington Double Star Catalog (WDS), should be able to use VizieR and Aladin to make hosted at http://ad.usno.navy.mil/proj/WDS/wds.html; measurements on neglected pairs all over the sky— this exhaustive database is the authoritative source the researcher is not limited to studying just those for all modern double star research and is maintained stars that can be seen from his or her location on the at the U.S. Naval Observatory. earth! This research has also made use of the VizieR I urge amateurs with the proper computer equip- catalogue access tool, CDS, Strasbourg, France. The ment to try a few cases to see how easy this really is original description of the VizieR service was pub- and to contribute hard scientific data to a growing lished in A&AS 143, 23. database, the WDS.

Richard Harshaw has been viewing the heavens for 50 years, the last 5 from his new home in Cave Creek, Arizona. He served on the board of the Astronomical Society of Kan- sas City while a resident of that city, and has served two terms as President of Phoenix’s Saguaro Astronomy Club and is currently its Secretary and newsletter editor. Richard has logged over 26,000 double star observations, including over 1,400 measurements registered with the WDS. He is the author of several papers for astronomical journals and also one book, The Complete CD Atlas of the Universe (published by Springer Verlag).

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Student Measurements of the Double Star STFA 28AB Compared with 18th - 21st Century Observations

Mark Brewer1,2,3,4, Jolyon Johnson5, Russell Genet3,4,6, Anthony Rogers2,4, Deanna Zapata1, William Buehlman1, Gary Ridge1,2, Hannah Jarrett1, Stephen McGaughey4,7, and Joseph Carro3,4

1. Victor Valley Community College, 2. High Desert Astronomical Society, 3. Central Coast Astronomical Society, 4. California Double Star Association, 5. California State University, Chico, 6. California Polytechnic State University, 7. Haleakala Amateur Astronomers

Abstract: Five students participated in a summer double star workshop at the Lewis Center for Educational Research in Apple Valley, California. An 8-inch Schmidt-Cassegrain telescope with a 12.5mm Celestron Micro Guide eyepiece was used to measure the position angle and separation of the double star STFA 28AB which was found, respectively, to be 170° and 108 arc seconds. The results were compared to late 18th and early 19th century observations as well as the most recent ten observations listed in the Washington Double Star Catalog. The measured separation changed by 20 arc seconds between 1781 and 1800 and then did not change significantly for the subsequent 212 years. The authors suggest either a procedural error by Herschel or, if binary, the orbital inclination of the system may explain the change.

Introduction A two-day Summer Double Star Workshop was held by the High Desert Astronomical Society (HiDAS) and the Central Coast Astronomical Society (CCAS) to measure and report on the double star system µ Boötis (STFA 28AB). The observations were made at the Lewis Center for Educational Research in Apple Valley, California by a team of students from Victor Valley College. The star system STFA 28AB is identified in the Washington Double Star Catalog (WDS) as WDS 15245+3723, located at right ascension 15hr 24' 05'' Figure 1: The observers from left to right: Gary Ridge, Mark Brewer, and declination +37° 23'. The magnitudes of the pri- William Buehlman, Deanna Zapata, and Hannah Jarrett. mary and secondary stars are listed as 4.3 and 7.1, respectively. We compared our observations to late (SIMBAD) were used to find different identifiers, 18th and early 19th century observations, as well as including 51 Boo A, ADS 9626, BDS 7258, CHR the most recent ten observations listed in the WDS. 181A, H 6_17, IDS 15207+3742, mu 1 Boo, STFA The WDS and the Set of Identifications, Meas- 28Aa-BC, STFA 28AB, SAO 64686, STTA 139, and urements, and Bibliography for Astronomical Data TYCO-2 2570-01521-1.

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Student Measurements of the Double Star STFA 28AB Compared with 18th - 21st Century ...

Figure 2: An illustration of the star system STFA 28Aa- Figure 3: William Herschel 1738 – 1822 BC. The figure shows stars A, B, and C. The primary is a double star that cannot be visually separated.

Background STFA 28AB was discovered by William Herschel over two hundred years ago and has been observed by many astronomers, each with a unique identifier. STFA is the identifier for Friedrich Georg Wilhelm von Struve. The letters “AB” refer to the brightest components of the system. STFA 28AB also has “a” and “C” components which means the system is composed of at least four stars. Figure 2 shows the three brightest stars in the system STFA 28Aa-BC. William Herschel (1738 – 1822), Figure 3, a Ger- man-born astronomer, is listed in the WDS under the reference code “H.” From October 1779 to 1792, he discovered and measured double stars from his home in Bath, England. Herschel presented his observations to the Royal Society of London in 1782 of 269 double or multiple systems (Herschel 1782) and in 1784 of 434 systems (Herschel 1784). Figure 4: This is the telescope William Herschel used to discover Herschel designed and built a 6.2-inch aperture, 7 the double star STFA 28AB. The photograph of astronomer Brian Manning was taken by Richard Berry at the Herschel Museum in -foot focal length Newtonian telescope with two small Bath, England. keys in the stand that allowed the observer to follow the sky in altitude and azimuth. Herschel made over 200 telescopes with apertures between 6 and 9 inches

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Student Measurements of the Double Star STFA 28AB Compared with 18th - 21st Century ...

Figure 5: Pre-1900 astronomers who observed STFA 28AB. Left to right: Giuseppe Piazzi 1746 – 1826, Sir James South 1785 – 1867, Friedrich Georg Wilhelm von Struve 1793 – 1864, and William Henry Smyth 1788 – 1865.

on alt-azimuth stands similar to the one shown in Figure 4. Several other pre-1900 observers measured STFA 28AB (Figure 5). Giuseppe Piazzi (1746 – 1826), listed in the WDS under the reference code “Pz,” is most famously known as the discoverer of the dwarf planet Ceres. He supervised the compilation of the Palermo Catalogue of stars published in 1802 and revised in 1814 (Darling 2012), containing 7,646 star entries, including his measurements of STFA 28AB in 1800. Sir James South (1785 – 1867), listed in the WDS under the reference code “SHJ,” was a member of the Royal Astronomical Society. He observed and cata- loged 380 double stars prior to 1824, including STFA 28AB in 1821. Friedrich Georg Wilhelm von Struve (1793-1864), listed in the WDS under the reference code “StF,” is most famous for his Catalogus novus stellarum du- plicium, published in 1827 (Batten 1977). He observed STFA 28AB in 1837. Admiral William Henry Smyth (1788 – 1865), listed in the WDS under the reference code “Smy,” reported his observation of STFA 28AB in 1832. Smyth built his own observatory in Bedford, England, where he published his now fa- Figure 6: Anthony Roger’s 8-inch Meade Schmidt- Cassegrain Telescope mous Cycle of Celestial Objects and The Bedford Cata- log containing 1,604 double stars and nebulae.

Methods The observers used the the drift method to deter-

An 8-inch Meade Schmidt-Cassegrain go-to equa- mine the scale constant. A star was positioned on the torial telescope (Figure 6) equipped with a 12.5mm linear scale of the Micro Guide eyepiece and the eye- Celestron Micro Guide eyepiece was used for our ob- piece was rotated such that the star would drift pre- servations. A stopwatch which reads to the nearest cisely along the linear scale when the the clock-drive 0.01 seconds was used for timing. was turned off. The time it took, in seconds, for the

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Student Measurements of the Double Star STFA 28AB Compared with 18th - 21st Century ...

primary star to move across the linear scale’s 60 division marks was estimated with the stopwatch. The average of 10 drift times was used to determine the scale constant using the equation

15.0411td cos( ) Z = D

where Z is the scale constant in arc seconds per division, 15.0411 is the Earth’s rotational rate in arc seconds per second, t is the average drift time in seconds, d is the declination of the calibration star in degrees, D is the number of division marks on the linear scale (60). The separation was determined by aligning both the primary and secondary stars along the linear scale, and the number of divisions between the stars was estimated to the nearest 0.1 divisions. The stars were repositioned at different points along the linear scale after each observation to avoid measurement bias. After 10 trials, the average, standard deviation and standard error of the mean were calculated and multiplied by the scale constant to determine the Figure 7: William Buehlman taking a measurement. separation in arc seconds. The position angle was determined by again aligning both stars on the linear scale, with the pri- erage sky conditions and a temperature of 80°F. Table mary star on the 30th division, which marks the pre- 1 lists the averages (mean), standard deviations, and cise center of the eyepiece. The observers then disen- standard errors of the mean for the drift time, separa- gaged the clock-drive, allowing both stars to drift to tion, and position angle measurements. Toward the the inner protractor ring of the Micro Guide eyepiece. end of the workshop, the star system approached the When the primary star reached the protractor, the zenith and observations ended. The average drift time clock-drive was reengaged and the primary star’s po- yielded a scale constant of 9.73 arc seconds per divi- sition was estimated to the nearest degree. The eye- sion. piece was rotated 180° between each observation to reduce bias (Frey, 2009). A 90° correction was applied Comparisons and Conclusion to all position angle estimates as required with the Table 2 lists the measurements from the late 18th Micro Guide eyepiece, and a 180° correction was ap- and early 19th century observations. Table 2 also com- plied to half of the observations to account for the ro- pares the separation and position angle differences tation after each observation. The average, standard and percentage differences to our measurements in deviation, and standard error of the mean were calcu- Table 1. Table 3 lists the last ten years of separation lated for 7 trials. and position angle measurements as well as their average, standard deviation, and standard error of the Observations mean. Figure 8 shows the students doing a statistical Observations were made on June 15, 2012 analysis of their data. (B2012.45) in the parking lot of the Lewis Center for We found the 20.0 arc second difference from the Educational Research in Apple Valley, California. 1781 Herschel measurement significant by 9.5 stan- Figure 7 shows a student making a measurement. dard deviations. The 4.0 arc second difference from Observations took place during a new moon, with av- the 1800 measurement by Piazzi was a statistically

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Student Measurements of the Double Star STFA 28AB Compared with 18th - 21st Century ...

Table 1: Student Measurements

Units # Obs. Std. Dev. Mean Std. Mean Err. Drift Time Seconds 10 0.21 48.85 0.06

Separation arc seconds 10 2.1 108 0.7 Position angle degrees 7 1.2 171 0.4

Table 2: Student’s observations compared to late 18th early 19th century observations provided by Brian Mason.

Historical Observations Comparison to Present Study Position Position angle Separation dif- Position angle Separation Separation Epoch angle difference ference percentage percentage (arc seconds) (degrees) (degrees) (arc seconds) difference difference 1781 170.4 128.0 0.6 20.0 0.4 15.0 1800 171.5 112.0 0.3 4.0 0.3 3.5 1821 171.9 108.5 0.9 0.5 0.5 0.5

Table 3: The last 10 observations provided by Brian Mason.

Position angle Separation Date Observer Code Telescope Aperture (degrees) (arc second) 2006.402 170.0 109.0 UPR2008b 31-inch

2006.571 170.9 107.94 Vim2008b 5-inch

2008.276 169.9 107.4 Ant2010b 10-inch

2008.311 170.0 108.7 Ant2010b 10-inch

2009.15 172.0 108.6 Bin2010a 4-inch

2009.266 170.9 108.63 Arn2009d 8-inch

2009.299 170.8 107.4 Abt2010b 10-inch

2009.514 170.8 108.91 Bvd2010c 11-inch

2010.419 170.7 107.7 Ant2011b 10-inch

2010.52 171.0 108.61 StJ2011 6-inch

Average 171.0 108.0

St. Dev. 0.6 0.6

St. Err. Mean 0.2 0.2

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Student Measurements of the Double Star STFA 28AB Compared with 18th - 21st Century ...

Acknowledgments We thank Dave Arnold and Vera Wallen for their critical reviews and Richard Berry for the image from the Herschel Museum in Bath, England. We thank Brian Mason for sending a list of past observations of the double star. We thank the High Desert Astro- nomical Society and the Central Coast Astronomical Society for providing guest speakers and astronomers for the workshop, including Chris and Reed Estrada. We thank the Lewis Center for Educational Research for letting us use their facilities. We thank the Cali- fornia Double Star Association, Luz Observatory, Figure 8: The authors having fun while preparing a scientific paper. Pine Flats Observatory, and Sycamore Rocks Obser- vatory for supporting the workshop. This research has made use of the WDS Catalog and SIMBAD data- insignificant 1.9 standard deviations. The 0.5 arc sec- base. ond difference from the 1821 measurement by Sir James South was only 0.24 standard deviations away References from our measurement and for the past ten years the Batten, A. H. 1977. "The Struves of Pulkovo - A fam- separation and position angle has not changed by any ily of astronomers." Journal of the Royal Astro- statistical amount. Therefore, the separation of STFA nomical Society of Canada. 71, 345. 28AB has been essentially constant for 212 years since Piazzi's measurement. Darling, David. 2012. “Giuseppe, Piazzi.” The Ency- We offer three possible causes for the large re- clopedia of Science. www.daviddarling.info/ ported change in separation between the 1781 and encyclopedia/P/Piazzi.html. 1800 observations: 1) technology of the late 18th cen- Frey, Thomas G. 2009. “Visual double star measure- tury may not have allowed the same accuracy as more ments with an alt-azimuth telescope.” Journal of modern equipment (it has been suggested that this is Double Star Observations. 4 (2), 59. common in early observations); 2) there may have been a transcription error when the measurement Herschel, William. 1782. “Catalog of double stars.” was initially recorded; 3) if the double star is binary Philosophical Transactions of the Royal Society of and the orbit is nearly on-edge as seen from Earth, London. 72, 112-162. the secondary may have approached greatest elonga- Herschel, William. 1784. “Account of some observation in the late 18th century. With a separation over tions tending to investigate the construction of 100 arc seconds, the secondary could remain there for the heavens.” Philosophical Transactions of the centuries as seen from Earth. Causes 1 and 2 were Royal Society of London 74, 437-451. not tested by the present study due to a lack of access to period technology or original data sheets. Cause 3 Mason, Brian. 2012. Washington Double Star Catalog. is the most unlikely, though it is supported by the Astrometry Department, U.S. Naval Observatory. lack of change in position angle. If the orbit is nearly ad.usno.navy.mil/wds/wds.html. edge-on, we would not expect to see a change in position angle until inferior conjunction.

Mark Brewer led the workshop and observations, is a student at Victor Valley Community College, and is an intern at NASA's Jet Propulsion Laboratory. Jolyon Johnson majored in Geology at Califor- nia State University, Chico, and is an experienced double star observer. Russ Genet is a Research Scholar in Residence at California Polytechnic State University and an Adjunct Professor of Astronomy at Cuesta College. Deanna Zapata, William Buehlman, Gary Ridge, and Hannah Jarrett are students at Victor Valley Community College and participated in the workshop. Anthony Rodgers, Stephen McGaughey, and Joseph Carro are experienced astronomers.

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CD Double Star Measures, Jack Jones Memorial Observatory: Report #5

James L. Jones

22665 Bents Rd NE Aurora, OR 97002 [email protected]

Abstract: This report submits 100 CCD measurements of 90 multiple star systems for inclusion in the WDS. Observations were made during the calendar year 2011. Selected results are discussed.

This paper reports on double star observations cates the number of nights that contributed to the and measurements made at the Jack Jones Memorial measurement. NAME, RA DEC, and MAGS columns Observatory during Calendar year 2011. are taken from the WDS. The telescope used is indi- Some observations were made using a Celestron cated in the Notes column of Table 1. 11-inch (28 cm) f/10 SCT with a Meade f/6.3 focal ALI 1021 01550+4012 reducer/field flattener. This combination yields a (Rho = 8.9, Theta = 316, mags = 12.5, 12.8 ) pixel scale of approximately 0.95 arcsec/pixel. This double was discovered by A. Ali in 1928 and not Most observations were made using a Celestron observed since it’s discovery. 14-inch (35 cm) f/10 Classic SCT with an OpTec 0.5X The author measured this pair as Rho = 3.65, telecompressor. This combination yields a pixel scale Theta = 296.9 which is a large change from the 1928 of approximately 0.87 arcsec/pixel. measurement. All observation utilized an SBIG-ST8XME cam- The J2000 coordinates of this pair are era with a KAF-1603ME Kodak NAB sensor. 015458.499+401157.28 and 015458.145+401159.54 Multiple images of each target were solved using (UCAC2). Both of these stars have significant proper "Astrometrica". Position Angle and Separation and motion with the A component pmRA = 71.8 and their associated standard deviations were computed pmDEC = -94.5 and the B component pmRA = -106.6 from the RA and Dec of the primary and secondary and pmDEC = 17.8 . The UCAC2 coordinates, yield a using software written by the author. The precision J2000 position of Rho = 4.64, Theta = 299.13. YB6 of each observation was quantified and reported by catalog (derived from NOMAD) provide Vmags of calculating the standard deviation of the image set. 11.090 and 11.380. The UCAC2 catalog was used in most cases for It appears that the large and opposite proper mo- image solution. Where UCAC2 was unavailable or tion of these two stars accounts for the large change didn't provide adequate reference stars, USNO-B1.0 in Rho and Theta between 1928.88 and 200.914. or UCAC3 was used. POU 3483 18415+2349 Results and Discussion (Rho = 11.4, Theta = 182, mags = 12.9, 13.9) Position Angle (θ) and Separation (ρ) measure- This double was discovered in 1905 by M. A. ments are reported in columns θ and ρ respectively Pourteau ( Rho = 8.0, Theta = 186.0). in Table 1. The precision of θ and ρ is reported in Gellera measured this pair from prints of the columns σ(ρ) and σ(θ) and refers to the standard de- Polomar Observatory Sky Survey plates (1952.526, viation of θ and ρ for the image set. Column N indi- Rho = 12.51, Theta = 182 )(Gallera, 1984), (Gallera,

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CD Double Star Measures, Jack Jones Memorial Observatory: Report #5

verted from the 2MASS J-K magnitudes are 14.79 and 14.50. B-V values converted from the same source are 1.32 and 1.30 using the same methodology. Both stars are quite red which accounts for the difference between observed unfiltered magnitudes and WDS magnitudes. SEI 937 20097+3510 (Theta=67, Rho=25.3, mag 11.73, 12.4) SEI 937 was discovered by J. Scheiner in 1896 and observed twice since its discovery. The WDS Precise Coordi- nate is listed as 200942.37+351101.5. There is a star of approximately 11.7 unfiltered magnitude at that coordinate but no secondary. It appears that the coordinate of the pair reported as SEI 937 is 200942.846+350857.79 (UCAC2). It should be noted Figure 1. Cropped mage of Pou 3483 showing the three stars in that CCDM locates the primary of SEI 937 at question. 200942.9+350858 POP 185AD 20060+3821 1990). (Theta=62, Rho=128.8, pri mag 10.29) POP It was measured again from 2 MASS catalog 185AD is part of a six star system that was discov- (1997.44, Rho = 11.37, Theta = 182.4 ) ered by G.M Popovic in 1896 and observed 5 times This pair is part of a three star chain of stars since its discovery. oriented from north to south (Figure 1). Gallera The entry for POP 185AD in the WDS does not (Gallera, 1984) notes that “B is double, a noticeable include a magnitude for the D component. Using the mpg 16 attached to B in PA 220”. This can clearly be conversion formula of Dymock and Miles (2009) seen in Figure 1. The northern star is located at co- yielded a V magnitude of 12.19 +/- 0.06 from CMC14. ordinate 184127.041+234825.46. The center star at POP 185AG 20060+3821 184127.003+234817.96 and the southern star at (Theta=293, Rho=18.9, pri mag 10.29) The WDS 184127.007+234814.10. Coordinates are from entry for POP 185AG does not include a magnitude 2MASS. for the secondary. Conversion from CMC14 yielded a It appears clear that the 1997 2MASS measure- V magnitude of 13.54 +/- 0.05. ment is based on the northern star and the southern star. Calculations using the 2MASS northern star Acknowledgements and center star yield Rho = 7.52 and Theta = 184 This research has made use of the Washington which is in closer agreement with Pourteau’s original Double Star Catalog maintained at the U.S. Naval measurement. Observatory and the VizieR catalogue access tool, The author used the northern star and the center CDS, Strasbourg, France. star for his measurements and so reported in Table 1 References (Rho = 7.49, Theta = 183.4) LDS 2446 19528+6732 Warner, Brian D., 2007 Minor Planet Bulletin, 34, (Theta=265, Rho=29.0, mag 16.0, 16.2) LDS 2446 113-119 was discovered by P. M. Luyten in 1953 and not ob- Dymock, Rodger and Miles, Richard, 2009, Journal of served since. The author measured the unfiltered the British Astronomical Association, 119,3, 149- magnitudes of the two stars to be approximately 156 14.2. At first glance the stated magnitudes in WDS appear to be too dim. Gellera, Lodi, 1984, Webb Soc., Double Star Circ. 3, However the magnitudes given in the LDS cata- part 1, 3-28 log, and repeated in the WDS, are blue photographic Gellera, Lodi, 1990, Astronomische Nachrichten 311, magnitudes. Using the conversion methodology of 117-121 Warner (2007), the V magnitudes of the pair con-

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CD Double Star Measures, Jack Jones Memorial Observatory: Report #5

NAME RA DEC MAGS θ σ(θ) ρ σ(ρ) DATE N NOTES POP 178AC 01260+4326 11.4 11.0 247.7 0.04 20.61 0.02 2011.914 1 1 ES 2586 01340+4416 9.53 9.67 98.6 0.009 44.51 0.01 2011.914 1 1 ALI1187 01434+4031 11.50 12.11 40.6 0.03 13.05 0.01 2011.914 1 1 LDS3321 01529+3201 11.23 13.9 150.5 0.01 63.70 0.007 2009.922 1 1 ALI1021 01550+4012 12.5 12.8 296.9 0.7 3.65 0.09 2011.914 1 1, 3 LDS3324AB 01554+4047 12.9 13.8 299.9 0.009 117.82 0.01 2011.914 1 1 LDS3324AC 01554+4047 12.9 18.9 70.0 0.10 113.43 0.10 2011.914 1 1 STF 187AB 01576+3134 9.68 11.90 190.3 0.12 11.04 0.003 2011.922 1 1 BAR 21BC 01576+3134 11.90 15.9 243.6 na 19.76 na 2011.922 1 1, 5 ALI1023 02067+4015 11.58 11.76 244.2 0.10 11.95 0.009 2011.914 1 1 ALI1024 02085+3944 11.4 12.3 355.4 0.06 9.36 0.005 2011.914 1 1 ALI 750 02164+3839 13.3 13.4 224.6 0.11 13.97 0.03 2011.914 1 1 ES 164 02180+4052 9.33 13.6 331.5 0.08 9.61 0.02 2011.922 1 1 ES 1502AB 02241+4137 10.90 11.7 168.6 0.06 6.64 0.03 2011.922 1 1 ES 1502AC 02241+4137 10.90 11.19 24.7 0.09 15.17 0.009 2011.922 1 1 ES 49AB 02249+4704 8.75 11.63 150.5 0.04 37.33 0.01 2011.922 1 1 ES 1503 02276+4206 11.35 13.0 55.0 0.24 4.93 0.07 2011.922 1 1 FOX 126AB 02284+4248 9.11 12.26 214.4 0.02 15.83 0.008 2011.922 1 1 LMP 29AC 02284+4248 9.11 13.96 291.3 0.01 53.11 0.02 2011.622 1 1 ES 2408 02355+3322 10.8 12.3 16.5 0.09 9.35 0.02 2011.922 1 1 ES 2409 02384+3308 10.09 14.6 77.5 0.10 11.81 0.03 2011.922 1 1 SEI 25 02382+3251 11.20 12.22 268.3 0.02 24.04 0.01 2011.922 1 1 LDS 880 02448+2852 13.5 13.6 207.5 0.04 35.48 0.02 2011.922 1 1 HJ 329 02539+3142 8.2 13.7 108.1 0.02 35.38 0.03 2011.922 1 1 POU 690 05303+2327 13.6 14.4 314.5 0.17 15.81 0.08 2011.092 1 2 POU 689 05303+2347 13.3 13.9 63.2 0.04 16.69 0.08 2011.092 1 2 POU 695 05313+2323 13.2 13.3 119.3 0.12 18.65 0.06 2011.092 1 2 POU 696 05314+2313 13.6 14.4 90.7 0.08 18.32 0.09 2011.092 1 2 POU 697 05315+2320 13.4 13.5 127.9 0.08 11.36 0.01 2011.092 1 2 POU 698 05315+2318 11.9 14.6 122.2 0.07 10.88 0.03 2011.092 1 2 POU 705 05318+2321 13.2 14.1 28.6 0.10 17.01 0.03 2011.092 1 2 POU 710 05322+2321 13.6 14.5 12.4 0.07 10.69 0.02 2011.092 1 2 POU 716 05329+2434 13.8 14.4 153.1 0.14 13.80 0.04 2011.092 1 2 POU2851 07386+2309 12.8 12.9 48.8 0.04 13.58 0.04 2011.092 1 2 POU2861 07406+2332 12.9 13.2 226.0 0.11 13.27 0.02 2011.092 1 2 POU2894 07483+2328 11.01 14.0 97.4 0.05 12.34 0.04 2011.092 1 2 POU2904 07535+2410 11.3 11.8 69.6 0.03 13.53 0.01 2011.092 1 2 POU2908 07559+2449 11.43 12.59 269.4 0.10 11.86 0.02 2011.092 1 2

Table continues on next page.

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CD Double Star Measures, Jack Jones Memorial Observatory: Report #5

NAME RA DEC MAGS θ σ(θ) ρ σ(ρ) DATE N NOTES ALI 377 18299+3633 12.5 12.7 273.6 0.06 7.43 0.007 2011.933 1 1 SLE 188 18319+2253 12.58 13.9 99.3 0.06 17.70 0.08 2011.582 1 1 SLE 212 18354+2243 12.27 13.4 255.1 0.06 14.29 0.01 2011.577 1 1 POP 17 18390+3501 13.27 13.31 15.8 0.05 8.63 0.003 2011.633 1 1 POU3460 18400+2324 10.33 14.2 121.3 0.02 11.61 0.007 2011.608 2 1 POU3464 18402+2328 12.9 13.6 332.3 0.06 9.60 0.01 2011.608 2 1 POU3475 18410+2346 11.09 13.2 22.0 0.009 13.72 0.005 2011.608 2 1 POU3481 18414+2350 13.13 13.13 8.3 0.09 6.98 0.004 2011.608 2 1 POU3483 18415+2349 12.9 13.9 183.4 0.05 7.49 0.008 2011.608 2 1,3 POU3486 18416+2331 12.41 12.5 348.6 0.04 21.06 0.02 2011.608 2 1 POU3669 19030+2358 12.6 13.4 18.0 0.08 12.76 0.01 2011.933 1 1 POU3675 19035+2331 11.81 13.4 227.7 0.02 15.87 0.02 2011.933 1 1 MLB 290AB 19348+6748 8.8 11.8 78.3 0.13 19.23 0.07 2011.640 1 1 MLB1083 19361+6755 10.58 10.63 162.0 0.10 8.72 0.04 2011.640 1 1 LDS2446 19528+6732 16.0 16.2 264.8 0.04 29.17 0.13 2011.640 1 1,3 SEI 710 19528+3644 11.0 11.0 19.7 0.06 25.32 0.01 2011.538 1 1 SEI 712 19531+3633 11.25 11.91 60.7 0.01 14.64 0.005 2011.538 1 1 SEI 714 19534+3640 11.0 11.0 56.1 0.05 11.02 0.007 2001.538 1 1 SEI 769 19596+3321 12.04 12.5 228.2 0.007 23.66 0.008 2011.610 2 1 BEW 4 19596+3318 11.7 13.2 202.9 0.03 17.90 0.006 2011.610 2 1 SEI 784 20008+3337 12.50 12.74 158.8 0.03 23.45 0.008 2011.610 2 1 SEI 785 20010+3346 11.45 11.4 137.0 0.01 29.04 0.007 2011.615 1 1 SEI 789 20013+3346 10.69 12.7 347.4 0.02 16.88 0.008 2001.615 1 1 SEI 803 20024+3320 10.35 13.4 271.9 0.009 22.59 0.007 2011.609 2 1 SEI 841 20048+3359 12.27 12.66 307.1 0.02 26.68 0.005 2001.615 1 1 POU4208 20053+2349 14.02 13.07 169.2 0.06 19.22 0.02 2011.597 2 1 SEI 844 20053+3343 10.43 12.9 5.7 0.01 22.46 0.007 2011.612 1 1 POU5058 20549+2434 13.4 13.6 357.2 0.04 11.49 0.02 2011.626 1 1 POU4214 20059+2353 12.15 14.6 79.0 0.02 9.78 0.006 2001.612 1 1 POP 185AB 20060+3821 10.29 11.28 124.5 0.02 43.42 0.03 2011.604 1 1 POP 185AC 20060+3821 10.29 12.55 185.3 0.09 64.69 0.07 2011.604 1 1 POP 185AD 20060+3821 10.29 . 61.9 0.06 128.53 0.06 2011.604 1 1,3 POP 185AE 20060+3821 10.29 12.5 101.1 na 119.09 na 2011.604 1 1,4 POP 185AG 20060+3821 10.29 . 293.0 0.08 19.00 0.05 2011.604 1 1,3 SEI 929 20096+3459 10.87 11.60 31.2 0.13 20.81 0.07 2011.615 1 1 SEI 937 20097+3510 11.73 12.4 67.3 0.007 25.27 0.007 2011.618 1 1,3 BKO 99 20099+3509 11.5 12.5 65.7 0.04 8.95 0.005 2011.618 1 1 SEI 941 20103+3511 10.76 11.59 156.3 0.01 27.49 0.006 2011.618 1 1

Table concludes on next page.

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CD Double Star Measures, Jack Jones Memorial Observatory: Report #5

NAME RA DEC MAGS θ σ(θ) ρ σ(ρ) DATE N NOTES SEI 977 20117+3458 11.84 11.89 38.6 0.04 15.18 0.02 2011.618 1 1 SEI 987 20120+3454 11.40 12.4 336.2 0.03 23.20 0.005 2011.618 1 1 SEI1027 20139+3439 10.15 12.1 10.0 0.01 28.62 0.005 2011.618 1 1 POU4957 20455+2522 10.37 13.6 293.9 0.11 19.97 0.09 2011.618 1 1 POU4959 20455+2509 14.3 14.5 137.7 0.06 13.88 0.06 2011.622 2 1 POU4923 20436+2518 12.42 13.5 308.4 0.02 15.51 0.02 2011.618 1 1 POU4972 20462+2513 13.7 14.1 279.3 0.05 13.76 0.02 2011.622 2 1 POU4974 20462+2526 12.8 14.3 106.2 0.03 17.26 0.03 2011.618 1 1 POU4980AB 20465+2506 14.1 14.3 144.4 0.15 7.56 0.03 2011.618 1 1 POU4980AC 20465+2506 14.1 14.3 104.6 0.06 13.10 0.04 2011.618 1 1 POU5045 20513+2511 12.48 13.7 313.8 0.05 13.65 0.01 2011.626 1 1 POU5050 20518+2509 12.2 12.4 325.7 0.04 18.49 0.03 2011.626 1 1 POU5052 20525+2522 13.21 13.73 323.3 0.03 15.85 0.01 2011.626 1 1 POU5053 20529+2453 13.0 14.2 184.5 0.07 14.33 0.01 2011.626 1 1 POU5054 20532+2508 12.7 14.0 314.8 0.03 10.47 0.02 2011.626 1 1 POU5055 20543+2441 12.1 13.2 201.8 0.07 9.16 0.007 2011.262 1 1 POU5056AB 20543+2405 10.40 12.02 184.1 0.03 21.45 0.01 2011.262 1 1 POU5057AC 20543+2405 10.40 13.8 231.2 0.03 23.59 0.01 2011.262 1 1 STI2562 21165+5727 12.0 12.6 77.1 0.02 11.17 0.009 2011.640 1 1 STI2566 21202+5809 11.87 12.34 125.1 0.04 13.12 0.007 2011.640 1 1 POU5395 21314+2451 10.96 13.1 127.0 0.02 17.38 0.02 2011.933 1 1 STI2615 22057+5531 12.30 12.9 248.7 0.06 10.16 0.01 2011.640 1 1 STI2714 22210+5502 12.5 13.1 159.2 0.10 9.52 0.04 2011.640 1 1 HJ 1767 22264+5534 11.01 11.65 212.1 0.01 11.97 0.006 2011.639 2 1

Table Notes 1. 14” C14 Classic SCT 2. 11” C11 SCT 3. See discussion. 4. The presence of the F component just 2.1” west ot the E component makes the measurement of POP 185AE very difficult. While the observation in Table 1 is consistient with the observation made, I am very reluctant to quote an error. 5. Observation based on 2 images.

Vol. 9 No. 1 January 1, 2013 Journal of Double Star Observations Page 48

Observation and Measurement of 10 Double Stars: April 2012 – July 2012

Gaetano Lauritano

Giugliano in Campania, Naples,Italy [email protected]

Abstract: This report submits CCD measurements of ten pairs, observed in the period April 2012 – July 2012. All measurements were made at my urban location of Giugliano in Cam- pania (Naples) with aNewtonian 8" F5 on an equatorial mount.

Introduction Between April 2012 – July 2012 I performed pri- marily visual observations of several doubles. Some of these pairs I also performed measurements with Webcam Philips Vesta 675 with a IRCut filter at the prime focus of my Newtonian Skywatcher 8" F5. In some cases I also used a 2X apochromatic Barlow. For astrometric measurements I used the excellent software Reduc v4.6 by Florent Losse,. Method Usually I select the systems to be observed in the free software Sky Charts, comparing the parameters with the WDS. Additional information is collected at the website http://stelledoppie.goaction.it. When all members of my family are in bed for the night, I go to the east balcony of my house, Figure 1. A neighbor looks at me, intrigued by the instrumentation in my possession. The software for video capture is GiGiwebcap- ture. After capturing movies I return to the binary Figure 1: My primary telescope. Skywatcher Newtonian systems to make a visual observation. 8” F5 at work.

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Observation and Measurement of 10 Double Stars: April 2012 – July 2012

STF2264 STF2894: It is also known as 95 Herculis is veryr beautiful, A nice pair whose components are represented by bright pair in Hercules. The primary was sky blue a white star and a red companion. The system is lo- and it's companion was a rich, golden yellow, Figure cated on the border with Pegasus, Figure 4. 2.

Figure 4: STF2894 Figure 2: STF2264

STF3049 STF2841 It is also known as Sigma Cassiopeiae is a binary Easy split. At the eyepiece there was some color star in the Cassiopeia.The two stars seems to have contrast of a whitish yellow primary with a tint of the same color of blue, Figure 3. blue on the secondary, Figure 5.

Figure 3: STF3049 Figure 5: STF 2841

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Observation and Measurement of 10 Double Stars: April 2012 – July 2012

STFB11 Flamsteed 1 Peg, a nice couple in Pegasus. Char- acterized by a strong difference in magnitude, Figure 6.

Figure 7: AGC 15

Figure 6: STFB11

AGC15AB Beta Cassiopeia, also known as Caph, although not the main star is the brightest in the constellation of Cassiopeia, having an apparent magnitude of 2.2. Caph is a yellow-white giant star of F2 spectral type, with a surface temperature of 7000°, slightly higher than our sun and is just about 50 light years from us. It is a variable star, the brightest of the class of Delta Scuti, whose magnitude varies between +2.25 and 2.31 with a period of .5 hours. Caph is almost four times the radius of the Sun and is 28 times brighter. The companion has an orbital period of 27 days, Fig- ure 7. Figure 8: STF 99 STF99 Not difficult to find, Primary bright and yellow, companion elusive, Figure 8. About this pair I’ve found an interesting files on the net. http:// adsa.bs.harvard.edu/full/1992Obs...112..125B

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Observation and Measurement of 10 Double Stars: April 2012 – July 2012

STFA4 This pair is composed of two yellow giants and is located near the open cluster NGC 752, Figure 9. References Stelle Doppie - http://stelledoppie.goaction.it/ Florent Losse http://astrosurf.com/hfosaf/ Andrea Console http://andreaconsole.altervista.org Registax - http://www.astronomie.be/registax/ Skychart - http://www.ap-i.net/skychart/ The Washington Double Star Catalog (WDS), U.S. Naval Observatory.

Figure 9: STFA 4

Table 1: Measurements of the 10 double stars.

NAME RA+DEC MAGS PA SEP DATE NOTE

AGC 15AB 00h09m10.68s +59°08' 59.2" 2.3 13.70 268 66.1 2012.539 Caph, Beta Cassiopea

STF 5 00h 10m 02.18s +11° 08' 44.9" 5.54 9.44 150.8 7.7 2012.539 34PSc

STF 12 00h 14m 58.84s +08° 49' 15.5" 6.06 7.51 142.4 11.9 2012.539 35PSc

STF 99 01h 13m 44.94s +24° 35' 01.6" 4.65 9.11 221.4 7.8 2012.539 PHI PSc

STFA 4 01h 56m 09.23s +37° 15' 06.5" 5.79 6.07 148.7 314.0 2012.539 56 And

STF2264 18h 01m 30.41s +21° 35' 44.8" 4.85 5.2 97.2 6.2 2012.320 95 Herculis

STFB 11 21h 22m 05.13s +19° 48' 15.7" 4.2 7.56 326.3 48.4 2012.523 1 Pegasi

STF2841 21h 54m 17.44s +19° 43' 05.3" 6.45 7.99 124.2 29.7 2012.523 STF2841

STF2894 22h 18m 56.17s +37° 46' 09.0" 6.21 8.85 193.3 16.0 2012.514 STF2894

STF3049 23h 59m 00.53s +55° 45' 17.8" 4.99 7.24 339.3 3.9 2012.523 Sigma Cassiopea

Gaetano Lauritano began to scan the sky in 1989 with a small 60/700. Attracted by all objects beyond Earth's atmosphere is affecting recently astrometric measurement of double stars. He observes from an urban location in Giugliano in Campania, Napoli, Italy. He maintains the blog “The Nights of Wonder” (http://thenightsofwonder.wordpress.com/), devoted to his astronomical works.

Vol. 9 No. 1 January 1, 2013 Journal of Double Star Observations Page 52

Comparing Two Calibration Methods of a Micro Guide Eyepiece using STF 1744AB

Eric Weise1, Jolyon Johnson2, Russ Genet3,4, Ryan Gelston3, Brian Reinhardt3, Tess Downs3, Tori Gibson3, and Austin Ross3

1. University of California, San Diego, CA 2. California State University, Chico, CA 3. Cuesta College, San Luis Obispo, CA 4. California Polytechnic State University, San Luis Obispo, CA

Abstract: Students at Cuesta College measured the double star STF 1744 AB and used two methods to calibrate the linear scale of the eyepiece. The drift method yielded a separation of 14.9 ± 0.6 arc seconds, which was 0.2 arc seconds different from the average of ten recent observations. Calibrating the scale by measuring the scale with a caliper gave a separation of 14.6 ± 0.5 arc seconds which was 0.1 arc seconds different from the average of ten recent observations. We concluded that the physical measurement of the linear scale is an appropriate method for the calibration of an eyepiece.

Introduction This project began as an astrometric inquiry into a double star, but pursuing our scientific curiosity we decided to compare two methods of calibrating the linear scale in the Celestron Micro Guide eyepiece. We observed the double star STF 1744 AB (Mizar) at Orion Observatory on June 28, 2012 (B2012.489). Ultimately there were two goals that this research group completed: 1) to learn how to locate and measure the astrometric parameters of double stars and 2) to compare two methods of calibrating the linear scale in a Micro Guide eyepiece. Methods Figure 1: The STF 1744 AB team. From left to right: Eric Weise, Measurements of STF 1744 AB were made with Ryan Gelston, Bryan Reinhardt, Austin Ross, Tori Gibson, and Tess an eleven inch Celestron telescope on a German Downs. equatorial mount. A Celestron Micro Guide eyepiece was used for the measurements. Two calibration seconds per division in the eyepiece. methods were used to determine the number of arc In the first method, the eyepiece was aligned

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Comparing Two Calibration Methods of a Micro Guide Eyepiece using STF 1744AB

such that when the clock drive was turned off and the primary of STF 1744 AB star drifted down the entirety of the linear scale with minimal deviation. The time it took the star to drift along the scale was measured using a stopwatch that reads to the nearest 0.01 second. The scale constant in arc seconds per division was calculated using the following equation:

t 15.4011cos(δ ) Z1 = 60

where Z1 is the scale constant using the drift method, t is the drift time, δ is the declination of the primary star (54.91°), 15.4011 is the rate of rotation of the Earth in arc seconds/second, and 60 is the number of divisions on the linear scale. The average of twelve drift times was used in our calculation. Figure 2: Genet (left) and Johnson (right) measure the length of the The second calibration constant was found by linear scale. Inset: calipers and disassembled eyepiece. disassembling the eyepiece and measuring the length of the linear scale using a caliper. (See Figure 2.) The scale constant was then determined with the age, standard deviation, and standard error of the following equation: mean were calculated for all separation, position angle, and calibration constant measurements. 205625 s Z = 2 60 Fl Results and Analysis

Our results are compared to the average of the where Z2 is the scale constant using the calipers, 205,625 is the number of arc seconds per radian, s is ten most recent observations sent by Brian Mason in the length of the linear scale in millimeters, 60 is the Table 1. The first of the ten observations was made number of divisions on the linear scale, and Fl is the on B2007.474 and the last observation was made on focal length of the telescope (2800 mm) as specified B2011.359. The calibration constants that were used by the manufacturer. The average of five measure- to convert separation from divisions to arc seconds ments of s was used in our calculation. were found to be 7.38 ± 0.18 arc seconds/division us- To determine the separation we lined up the ing the average drift time and 7.26 ± 0.29 arc sec- stars on the linear scale in the eyepiece and twelve onds/division using the calipers. The uncertainties measurements were taken of the separation to the are found by propagation of the standard error of the nearest 0.1 division. After each measurement the mean of the number of divisions and the measure- stars were repositioned on the scale to reduce bias. ments of the drift time and length of the linear scale The average separation in divisions was multiplied (Taylor 1997). From the drift time calibration we found the by each of the scale constants, Z1 and Z2, to compare the accuracy of the two methods described above. separation of STF 1744 AB to be 14.9 ± 0.6 arc sec- We measured the position angle of STF 1744 AB onds, which is 0.2 arc seconds different from 14.7, by the drift method. We began by placing the pri- the average of the last ten observations (Mason mary star on the midpoint of the linear scale and 2012). This is a difference of 0.16 standard deviations rotating the eyepiece such that the secondary star of our separation value. From the caliper calibration was also on the linear scale. The clock drive was then we found the separation of STF 1744 AB to be 14.6 ± deactivated and the star began to drift with the 0.6 arc seconds. The difference from the average of Earth's rotation. The angle that the primary star the the past observations is 0.1 arc seconds and is passed through on the inner protractor was esti- 0.06 standard deviations of our separation away from mated. The telescope was reset and the process re- our average of past observations (Mason 2012). Fur- peated eleven more times. It was necessary to apply thermore, the precisions of the calibration constants a 90° correction to our data because of the nature of are calculated by the formula: the Micro Guide eyepiece (Teague 2004). The aver-

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Comparing Two Calibration Methods of a Micro Guide Eyepiece using STF 1744AB

Table 1: The average, standard deviation and standard error of the mean of our data as well as the last ten observations provided by Brian Mason. The standard deviation and the standard error of the mean for our separation were found by addition in quadrature (Taylor 1997)

Last 10 Observations Our Data (Mason 2012) Separation Separation Length of Lin- from Cali- Drift Time, from Drift Position Separation Position An- ear Scale, s per t Time Angle (arc sec- gle (mm) (arc sec- (sec) (arc seconds) (degrees) onds) (degrees) onds) No. Obs. 12 12 5 12 12 10 10

Average 50.09 14.9 5.93 14.6 156.0 14.7 152.7 Standard 0.46 1.2 0.42 1.6 1.3 0.7 0.4 Deviation Standard Error of the 0.13 0.4 0.19 0.6 0.4 0.2 0.13 Mean

x Acknowledgments p= σx We would like to thank Brian Mason with the United States Naval Observatory for providing us where p is the precision, x is the calibration con- with the past observations of STF 1744 AB. We are stant, and σx is the uncertainty of the calibration also grateful for the use of the facilities at Cuesta constant. The precision of the drift method scale con- College and Orion Observatory. We thank our exter- stant is 0.024 and the precision of the caliper scale nal reviewers, Tom Smith of the Dark Ridge Obser- constant is 0.040. The position angle was found to be vatory and Vera Wallen (“Dr. Eagle-Eye”). And fi- 156.0° ± 0.4° which is 3.3° and 2.5 standard devia- nally we would like to thank the Collins Educational tions different from the average of past observations. Foundation for the donation of the Celestron CGEM- Conclusion 11 telescope that we used. This was the first time the After comparing the differences of two methods telescope was used for scientific observations. of calibrating the linear scale in a Micro Guide eye- References piece we have determined that both methods are accurate because the uncertainties of the scale con- Frey, Tom. 2008. “Visual Double Star Measurements stants overlap. Our calculated precision for drift time with an Alt-Azimuth Telescope.” In the Journal method was ultimately greater than the caliper of Double Star Observations. Vol. 4 No.2. Spring method. Interestingly enough, our data shows that 2008. the method of physically measuring the linear scale Mason, Brian. 2012. Astronomy Department, U.S. and using the manufacturer-provided focal length Naval Observatory. Personal correspondence. appeared slightly more accurate than measuring the drift time. Therefore, even though the caliper method Taylor, John R. 1997. An Introduction to Error is less precise method, it is still useable. Although Analysis Second Edition. Pp 141-147. Sausalito: using a caliper and a magnifying glass can be a more University Science Books. tedious task, it is a less time consuming operation Teague, Tom. 2004. “Simple Techniques of Measure- and can be done in the daytime. Our measured posi- ment.” In Observing and Measuring Visual Dou- tion angle is greater than the accepted value by 2.5 ble Stars, ed. Bob Argyle. New York: Springer. standard deviations which is statistically significant. We attribute this large error to our failure to rotate the eyepiece by 180° after each observation, which may have introduced a systematic error to our measurements (Frey 2008). This extreme oversight will be corrected in future research.

Vol. 9 No. 1 January 1, 2013 Journal of Double Star Observations Page 55

Visual Measurements of the Double Star STFA 38 AD

Jolyon Johnson1, Eric Weise2, Russell Genet3,4, Michael Anderson3, Samantha Choy4, Melinda Hart3, Bailey Kelley3, Zachery Noble3, Samantha Spurlin3, Bret Tabrizi3, and Sheena Wu4

1. California State University, Chico, CA 2. University of California, San Diego, CA 3. Cuesta College, San Luis Obispo, CA 4. California Polytechnic State University, San Luis Obispo, CA

Abstract: Students from Cuesta College and California Polytechnic State University measured the separation and position angle of the double star STFA 38 AD (Zeta Lyrae). The students analyzed the data and calculated a separation of 44.3 arc seconds and a position angle of 150.4°. These observations are within one standard deviation of 10 recent observations. Similar proper motion vectors suggest that STFA 38 AD could be a true binary star.

Introduction This project was part of a summer 2012 introductory astronomy course at Cuesta College. On Wednesday, June 27, 2012 (B2012.486), eight students from Cuesta College and California Polytech- nic State University, San Luis Obispo, observed the double star STFA 38 AD at the Orion Observatory. The observatory is distant from bright city lights in a sparsely-populated outskirt of Santa Margarita, Cali- fornia. It was a clear night which allowed unob- structed observation with few clouds and no wind. The three goals of this project were to: (1) give students the opportunity to observe and make their first quantitative measurements; (2) properly record and process data with statistical calculations; and (3) compare the results with recent observations. Figure 1. Astronomy students at the Orion Observatory. Front row Equipment and Procedures (left to right): Bret Tabrizi, Bailey Kelley, Samantha Spurlin, Sheena Wu, and Melinda Hart; Back Row: Eric Weise, Jolyon Observations were made with an equatorially- Johnson, Zachery Noble, and Michael Anderson. mounted 8 inch Meade Schmidt-Cassegrain telescope with a clock drive. A Celestron Micro Guide eyepiece

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Visual Measurements of the Double Star STFA 38 AD

was used for separation and position angle measure- data, and rotated the eyepiece 180° to reduce system- ments, while a stopwatch which reads to one hun- atic error, the process was repeated 15 times. A 90° dreth of a second was used to measure the drift time correction was applied as required for Celestron Mi- for calibrating the eyepiece. cro Guide eyepieces (Teague 2004). The drift method was used to calibrate the linear The initial data was recorded in a notebook and scale on the eyepiece. Drift times were found by lin- transcribed onto a Microsoft Excel spreadsheet. The ing up Gamma Draconis on the east end of the linear spreadsheet was used to calculate the average, stan- scale and turning off the tracking motor. Researchers dard deviation, and the standard error of the mean individually timed the travel of the star from one end for each set of measurements. of the linear scale to the other. Each researcher made two observations for a total of sixteen. The calibra- Results and Analysis tion equation used was: STFA 38 AD is located at right ascension 18h 44.8m and declination +37° 36m with a primary 15.0411t cos(δ ) magnitude of 4.3 and a secondary magnitude of 5.6. Z = 60 Table 1 shows the average separations and position angles, as well as standard deviations and standard where Z is the scale constant in arc seconds per divi- errors of the mean of the researchers' measurements sion, 15.0411 is the number of arc seconds the earth and the last 10 observations provided by Brian Ma- rotates per second, t is the averaged measured drift son (Mason 2012). time (64.52 seconds), δ is the declination of Gamma The average separation measurement was 44.3”, Draconis (51.48°), and 60 is the number of divisions only 0.3” more than the average of the previous 10 on the linear scale of the eyepiece. The number of arc measurements, which was 44.0” (Mason 2012). The seconds per division was calculated to be 10.1. average position angle measured was 150.4°, which Separation was determined by aligning the pri- is 0.5° more than the average of the previous 10 mary and secondary stars along the linear scale and measurements, which was 149.8° (Mason 2012). The estimating the separation to a tenth of a division. To measurements are within one standard deviation of increase precision, the researchers repeated the proc- the average of the previous 10 observations. ess a total of 15 times, measuring the separation at According to the WDS catalog, the primary star multiple points along the linear scale. The average has proper motion vectors of +25 milliarcseconds was then multiplied by the scale constant. right ascension and +24 milliarcseconds declination The position angle was estimated by placing the per year. The secondary star has vectors of +20 mil- primary star on the center of the linear scale and liarcseconds right ascension and +21 milliarcseconds ensuring both stars were aligned on the linear scale. declination per year (Mason 2012). These numbers After centering, the telescope’s tracking motor was are similar and suggest that the two stars may form disabled. The researchers estimated to the nearest a true binary star system. degree where the primary star crossed the inner pro- Conclusion tractor due to Earth's rotation (Teague 2004). After each researcher made an observation, recorded their Overall, the researchers effectively utilized a

Table 1. Observed measurements of STFA 38 AD compared to recent observations in the Washington Double Star catalog.

Sep. Mason Sep. PA Mason PA

# Obs. 16 10 16 10

Average 44.3” 44.0” 150.4° 149.8°

St. Dev. 0.3” 0.5” 1.5° 0.7°

St. Err. Mean 0.1” 0.2” 0.4° 0.2°

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Visual Measurements of the Double Star STFA 38 AD

telescope to observe and measure the double star References STFA 38 AD. The researchers used their measurements to compare the current position of the star to Mason, Brian. July 2012. Astronomy Department, prior observations. Additionally, the researchers con- U.S. Naval Observatory. Personal correspon- sidered the proper motion vectors of the stars and dence. hypothesize that the double star may be a gravita- Teague, Tom. 2004. “Simple Techniques of Measure- tionally bound binary. ment.” In Observing and Measuring Visual Dou- Acknowledgments ble Stars, ed. Bob Argyle. New York: Springer.

We thank Brian Mason for providing extensive

past observations of STFA 38 AD. In addition, appreciation is given to Dave Arnold, Thomas Frey, Tho- mas Smith, and Vera Wallen for reviewing this paper. Finally, special thanks go to Cuesta College and Orion Observatory for letting us use their facilities.

Jolyon Johnson is a Geology graduate of California State University, Chico. Eric Weise is a Physics major at University of California, San Diego. Both were science advisors for this introductory astronomy class. Samantha Choy and Sheena Wu are students at Cali- fornia Polytechnic State University, San Luis Obispo. Michael Anderson, Melinda Hart, Bailey Kelley, Zachery Noble, Samantha Spurlin, and Bret Tabrizi are students at Cuesta College. Russell Genet taught the astronomy course and is an Adjunct Professor of Astronomy at Cuesta College as well as a Research Scholar in Residence at California Polytechnic State University, San Luis Obispo.

Vol. 9 No. 1 January 1, 2013 Journal of Double Star Observations Page 58

Two Cuesta College Teams Observe Albireo

Jolyon Johnson1, Joseph Carro2, Eric Weise3, Russell Genet4,5, Brian Cahn5, Brittany Chezum6, C. McKenney Degnan4, Nicole Ford5, Anna Greene4, Nicholas Jaeger4, Rachel Johnson5, Kristen Nicholson4, Devanee Richards4, Joseph Richardson4, and Samantha Thompson5

1. California State University, Chico, CA 2. Central Coast Astronomical Society, San Luis Obispo, CA 3. San Diego University, San Diego, CA 4. Cuesta College, San Luis Obispo, CA 5. California Polytechnic State University, San Luis Obispo, CA 6. BIOLA University, Los Angeles, CA

Abstract: Two student teams observed the visual double star Albireo. One team used an 8 inch telescope while the other team used an 11 inch telescope. The teams found the separation to be 35.4” and 36.0”, respectively. The 8 inch team measured the position angle to be 54.7°. Both separation measurements and the position angle measurement of the 8 inch telescope are close to the most recent observation in the Washington Double Star catalog. The 11 inch team's position angle had an unresolved problem.

Introduction The 2012 Cuesta College Introduction to Astron- omy summer course consisted of students from Cuesta College and California Polytechnic State Uni- versity. Two separate observing groups unwittingly measured the same double star, Albireo (STFA 43 AB). Not wishing to produce two papers observing the same star on the same night, the groups merged to compare and jointly report their measured separations and position angles. Observations were made on June 25th, 2012 (B2012.483) at the Orion Obser- vatory in Santa Margarita, California. This project had two objectives: 1) expose stu- Figure 1: Zachery Noble, Joseph Richardson, Anna Greene, Joseph dents to quantitative measurements through the ob- Carro, and Eric Weise observed Albireo at the Orion Observatory servation of double stars and 2) compare their meas- using Carro's 11 inch telescope. urements to the most recent observation reported in

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Two Cuesta College Teams Observe Albireo

the Washington Double Star catalog (WDS). Table 1: The averages, standard deviations, and standard Equipment and Procedures errors of the mean for the measured separations with both An equatorial 8 inch Meade Schmidt- telescopes and position angle with the 8 inch. Cassegrain telescope and an alt-az Celestron C11, each equipped with a Celestron Micro Guide eyepiece, Telescope 8 inch Sep. 11 inch Sep. 8 inch PA were used to independently measure Albireo's separa- # Obs. 12 10 12 tion and position angle. Stopwatches which read to Average 35.4” 36.0” 54.6° the 0.01 seconds was used for drift timings. To determine the scale constant of the 11 inch St. Dev. 2.4” 0.9” 2.2° telescope, the observers positioned the primary star of St. Err. Mean 1.0” 0.2” 0.6° Albireo on the east end of the linear scale and disen- gaged the tracking motors. The observers using the with the 11 inch used the outer protractor. To reduce 11 inch telescope calculated the average time for the systematic error, the observers using the 8 inch tele- star to reach the west end of the linear scale to be scope rotated the eyepiece 180° after each trial, al- 32.5 seconds. The team then calculated the scale con- though this was not done with the 11 inch telescope. stant to be 7.2 arc seconds per division using the fol- A 90° correction was applied as required for the Micro lowing equation: Guide eyepiece (Teague 2004). Twelve trials were completed and analyzed using Microsoft Excel to find 15.0411td cos( ) Z = the average, standard deviation, and standard error 60 of the mean.

where Z is the scale constant in arc seconds per divi- Results and Analysis sion, t is the average drift time, δ is the declination of Table 1 shows the average separations measured the primary star of Albireo (27.95°), and 60 is the with both telescopes and the average position angle number of divisions on the linear scale. Due to limited measured with the 8 inch, as well as their standard observing time with the 8 inch telescope, we used the deviations and standard errors of the mean. The sepa- scale constant of 10.1 arc seconds per division deter- ration measurements are within one standard devia- mined by another project using the same telescope tion of each other and within 1.5 standard deviations and eyepice (Johnson et al. 2013). of the most recently reported WDS value of 34.8”. We To measure the separation, the observers posi- found the position angle derived with the 8 inch to tioned the telescope so both the primary and secon- also be within one standard deviation of the most re- dary stars were along the linear scale. The observers cent observation in the WDS of 54°. However, the po- then estimated the number of divisions between the sition angle measurement made with the 11 inch was two stars to the nearest 0.1 divisions (8 inch) and 0.25 18° different from the WDS catalog value. There was divisions (11 inch), as instructed by the telescope op- not enough time left at end of the class to resolve this erators (Johnson on the 8 inch and Carro on the 11 issue. inch). To reduce bias, the stars were repositioned onto Conclusions different divisions of the scale for each trial. The measurements were analyzed using Microsoft Excel With the use of two telescopes, we measured Albi- to find the average, standard deviation, and standard reo’s separation and position angle. This was a valu- error of the mean. The averages were multiplied by able experience for young college students learning the scale constants to find the separations in arc sec- science by doing science. With the merger of two ob- onds. serving teams, the students were able to communi- To measure the position angle of Albireo, the ob- cate and compare results in a single paper, thus limit- servers positioned the primary star at the center of ing new literature on this popular double star. the linear scale of the Micro Guide eyepiece. The right Acknowledgments ascension motor was turned off momentarily to allow the star to drift with the Earth’s rotation, and the ob- Thanks to classmate Zachery Noble for contribut- server estimated and recorded to the nearest degree ing observations. Thanks also to Tom Smith and Vera where the star crossed the protractor. The team with Wallen for their helpful reviews. We thank Orion Ob- the 8 inch used the inner protractor while the team servatory and Cuesta College for the use of their facilities

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Two Cuesta College Teams Observe Albireo

References Johnson, Jolyon, et al. 2012. “Visual Measurements of the Double Star STFA 38 AD.” Journal of Double Star Observations. Submitted. Mason, Brian. 2012. The Washington Double Star- Catalog. Astronomy Department, U.S. Naval Ob- servatory. http://ad.usno.navy.mil/wds/. Teague, Tom. 2004. “Simple techniques of measurement.” In Observing and Measuring Visual Dou- ble Stars, ed. Bob Argyle. New York: Springer.

Jolyon Johnson is a recent graduate from California State University, Chico, and was an advisor for the astronomy course. Eric Weise is a physics student at University of California, San Diego, and was an advisor for the astronomy course. Brian Cahn, Nicole Ford, Rachel John- son, and Samantha Thompson are students at California Polytechnic State University. Brittany Chezum, C. McKenney Degnan, Anna Greene, Nicholas Jaeger, Kristen Nicholson, Devanee Rich- ards, and Joseph Richardson are students at Cuesta College. Russell Genet led the astronomy course and is an Adjunct Professor of Astronomy at Cuesta College as well as a Research Scholar in Residence at California Polytechnic State University.

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Six Proper Motion Pairs Measured with the 2-meter Faulkes Telescope North

Rafael Caballero 1, Russell Genet2,5, J.D. Armstrong3,4,5,8, Steve McGaughey4,5, Cindy Krach5, Audreanna Leatualli5,6, Aaron Rohzinski5,7, Coleen Rohzinski5, Eric Rohzinski5, Noah Rohzinski5,7, McKayla Wandell5,6, John Martinez8, and Thomas Smith9

1. Agrupacion Astronomical Hubble, Martos, Jaen, Spain 2. California Polytechnic State University, San Luis Obispo, California 3. University of Hawaii, Institute for Astronomy, Maui, Hawaii 4. Haleakala Amateur Astronomers, Maui, Hawaii 5. Maui Double Star Association, Maui, Hawaii 6. Baldwin High School, Wailuku, Maui, Hawaii 7. Seabury Hall Middle School, Makawao, Maui, Hawaii 8. Las Cumbres Observatory Global Telescope network, Santa Barbara, California 9. Dark Ridge Observatory, Weed, New Mexico

Abstract: Multiple observations were made of six faint common proper motion pairs with the 2-meter Faulkes Telescope North on Haleakala by Maui middle school and high school students and their supporters. Of the six pairs, two are reported as newly discovered proper motion binaries. Individual reductions versus a single ‘track and stack’ reduction were compared.

identical telescope to another as the Earth turns. All Introduction of the telescopes in the network will be fully robotic The 2-meter Faulkes Telescope North (FTN) is and well instrumented (including high speed, low located on the 10,000 foot summit of Haleakala, a noise EMCCD cameras that could be used for lucky dormant volcano on Maui (http://www.faulkes- imaging or speckle interferometry of double stars as telescope.com/). Haleakala is blessed with abundant well as spectrographs on the 1- and 2-meter tele- clear dark skies and excellent seeing. FTN is one of scopes). the telescopes in the Las Cumbres Observatory A portion of the observational time on FTN has Global Telescope (LCOGT) network. In addition to been allocated to the University of Hawaii’s Institute the FTN, a matching 2-meter telescope, Faulkes for Astronomy (IfA) for public outreach and student Telescope South (FTS), is located a Siding Springs education. J.D. Armstrong, one of this paper’s coau- Observatory, Australia. thors, works jointly for IfA and LCOGT to coordinate More than a dozen 1-meter telescopes and ap- the use of this observational time. Two of us, Russell proximately two dozen 0.4-meter telescopes are being Genet and Steve McGaughey, suggested that student designed, built, and installed by LCOGT at diverse observations of double stars that resulted in pub- longitude and latitude locations around the globe to lished papers would be good use of a small portion of conduct research in “time-domain” astrophysics. Ob- this time. J.D. Armstrong agreed, and we set about jects can be kept under constant surveillance around organizing the Maui Double Star Association, which the clock as they are automatically passed from one consists of Maui middle school and high school stu-

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Six Proper Motion Pairs Measured with the 2-meter Faulkes Telescope North

Figure 2: Looking up a “Rafa” double. Left to right, MacKayla Wan- dell, Audreanna Leatualli, Aaron Rohzinski, Steve McGaughey, and Eric Rohzinski

covered proper motion binaries. Selection Although we selected ten pairs of stars for the observational session, we only had time to observe the six pairs listed in Table 1. The six pairs included two new uncataloged, common proper motion pairs, and four pairs already in the Washington Double Star Catalog (WDS, Mason et al. 2003). The two new pairs were found by looking for stars with noticeable movement in the Aladin plates (Bonnarel et al., 2000). Figure 1: Left to right, co-authors Steve McGaughey, J.D. Armstrong, and Russ Genet stand in front of the 2-meter Faulkes Telescope North Observations on the summit of Haleakala. At far right is John Pye, Astronomy In- structor at University of Hawaii, Maui College. Observations were made on the evening of April 1, 2012 with the 2-meter Faulkes Telescope North using its Spectra series 600 CCD camera. This instrument uses a 4k x 4k chip with 15 micron pixels. Used dents and their supporters. in 2x2 bin mode on FTN, the plate scale is about 0.3 One of this paper’s coauthors, Rafael Caballero, arc seconds per pixel, with a total field-of-view of recently developed a method for generating common about 10 arc minutes. Middle school and high school proper motion (CPM) pairs based on data bases in- students manned the Real Time Interface (RTI) tele- cluding recent Sloan Digital Sky Survey (SDSS) re- scope controls at the University of Hawaii’s Institute leases (Caballero 2012). He applied a version of his for Astronomy, Maui, under the supervision of J. D. method to generate CPM pairs for observation for this Armstrong and Steve McGaughey. Russ Genet par- paper that were too faint to observe with his telescope ticipated remotely via telephone and the Internet. in Spain, but would be relatively easy objects for the 2 -meter FTN telescope. Astrometry In this paper we report on the selection, observa- The images obtained were squares of around tion, and analysis of six faint CPM pairs. Four pairs 10x10 arc minutes. This large size made these im- had been previously recognized as double stars and ages very suitable for the software Astrometrica were listed in the Washington Double Star (WDS) (please see http://www.astrometrica.at/). We used the Catalog (Mason et. al. 2003). Two pairs have not been Track & Stack option of this software to create a sin- previously reported and we suggest they be consid- gle image combining the 5-6 images of each pair. The ered for inclusion in the WDS Catalog as newly dis- reduction was performed with the following configuration:

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Six Proper Motion Pairs Measured with the 2-meter Faulkes Telescope North

reported for this catalog should not effect our relative astrometry) The Focal Length was obtained by trial and error, while the Pixel Width and Pixel Height were taken from the camera spreadsheet configuration. The catalog USNO-B1.0 was selected because it yielded a higher number of reference stars. About 30 reference stars were located by the software in all the cases. After the reduction, the coordinates of each component were simply obtained by clicking over the star. The software automatically calculates the centroid as shown in Figure 4. In order to obtain good estimates of the centroids, the Aperture Radius (option Settings+Program) was set to a large enough value (in our case 15 pixels) to Figure 3: Making observations with the FTN at the University of include essentially all the light from the star. From Hawaii’s Institute for Astronomy, Maui. Front row left to right: Au- the coordinates, the distances and the position angles dreanna Leatualli, MacKayla Wandell,, and J. D. Armstrong. Back of each pair were readily obtained using the Hav- row left to right: Coleen Rohzinski, Aaron Rohzinski, Noah Rohzins- ersine formula (Sinnott, 1984). The results are shown ki, and Eric Rohzinski in Table 1. Coordinates and proper motions were obtained from the SDSS-DR8 survey (Adelman- - Focal Length: approximately 2000 mm (2 meter McCarthy et al. 2011), unless explicitly stated. The f/10) position angles are in degrees, the separations are in - Pixel Width = Pixel Height = 15 microns (but 30 arc seconds, and the proper motions are in millisec- microns when binned 2x2 as was he case for our ob- onds of arc/year. servations) - Catalog: USNO-B1.0 (systematic errors recently

Figure 4: Screen snapshot of Astrometrica centroiding.

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Six Proper Motion Pairs Measured with the 2-meter Faulkes Telescope North

Table 1 : Astrometric Measurements

ID RA DEC (2000) Mags Angle Sep. DATE PM-A PM-B Notes NEW 05 42 00.85 +82 19 42.29 16.23 18.00 33.18 15.11 2012.260 +017 -152 +020 -146 CBL 235 07 28 20.78 +31 00 11.7 15.1 17.8 296.06 9.45 2012.260 +025 -143 +020 -141 1 CBL 303 10 10 18.68 +01 07 19.8 16.9 18.2 113.77 8.68 2012.260 -106 +035 -099 +036 1 GWP1473 10 51 03.60 +14 58 19.8 14.0 15.1 73.98 13.89 2012.260 +018 -154 +042 -150 1 CBL 338 11 21 45.09 +02 16 58.0 14.4 18.9 98.78 10.62 2012.260 +009 -131 +012-141 1 NEW 11 22 05.89 +01 28 03.63 15.74 16.48 34.34 9.57 2012.260 -090 +086 -086 +072 2,3

Table notes: 1. only Angle, Sep., and Date are new data, the rest of each row is repeated from the WDS; 2. proper motions are from The Naval Observatory Merged Astrometric Dataset (NOMAD, Zacharias et al. 2005) for both components; and 3. R magnitudes are from SDSS-DR8.

Measurement Precision • Columns 6 and 7 include the sample standard The data of Table 1 correspond to the average deviation of the angle and separation individ- of the measurements over the individual images ob- ual measurements, respectively. tained for each pair. In order to determine the reli- • Columns 8 and 9 correspond to the standard ability of the results, Table 2 includes the following error of the mean (abbreviated by Sem.) of columns: both the angle and the separation. • The first two columns are the identifier and The values ≈0 indicate that the value is less than the coordinates of the pair. 0.01. A vital goal of our observations of faint double • The third column includes the number of im- stars with FTN was to establish the precision of our ages taken for each pair (all of them consecu- observations and this table helps to determine this tively during the same night). precision. We observe that the values are quite ac- ceptable except for the new pair located at 05 42 00.85 • Columns 4 and 5 correspond to the average of +82 19 42.29. Checking the images in Astrometrica the the angle and separation obtained after the reason for this lack of precision can be observed as individual reductions in Astrometrica (these shown in Figure 5: the histogram in an image for the columns correspond respectively to columns secondary is too blurred to provide a precise measure- Angle and Sep. of Table 1). ment.

Table 2: Individual measurement statistics

Number Angle Sep. Angle Sep. Angle Sep. ID RA DEC (2000) of images Avg. Avg. St. Dev. St. Dev. Sem. Sem. NEW 05 42 00.85 +82 19 42.29 5 33.18 15.11 0.83 0.18 0.41 0.09 CBL 235 07 28 20.78 +31 00 11.7 4 296.06 9.45 0.31 0.02 0.16 0.01 CBL 303 10 10 18.68 +01 07 19.8 5 113.77 8.68 0 0 0 0 GWP1473 10 51 03.60 +14 58 19.8 6 73.98 13.89 0.17 0.07 0.07 0.03 CBL 338 11 21 45.09 +02 16 58.0 5 98.78 10.62 0.23 ≈0 0.11 ≈0 NEW 11 22 05.89 +01 28 03.63 5 34.34 9.57 ≈0 ≈0 ≈0 ≈0

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Six Proper Motion Pairs Measured with the 2-meter Faulkes Telescope North

individual images to avoid saturation of pixel values. Average: sets the pixel value to the mean of the individual images. The range of pixel values is therefore preserved, and pixels will not saturate when stacking images. For faint targets and/or images using only a small fraction of the dynamic range, pixel values in the stacked image might appear quantized. Median: This option is useful for detecting comets in images, one of the main applications of Astromet- rica. However, Median only removes stationary objects if the tracking option is used. Since we were not tracking a moving object, such as an asteroid, there was no angular velocity. In this case moving objects are removed. Obviously the ‘Track & Stack’ option can save time by transforming many individual reductions into a single reduction over the combined image. How- ever, the question is how the use of this option affects the precision. In order to clarify this point we com- Figure 5: Imprecise centroiding pared the reductions obtained using the four Astro- metrica possibilities (that is, average of individual reductions, ‘Track & Stack’ with add, ‘Track & Stack’ ‘Track & Stack’ Comparison with SDSS with average, and ‘Track & Stack’ with median) with and 2MASS Measurements the measurements obtained from external catalogs. In As explained above, the reduced data for each particular we chose the SDSS-DR8 survey (Adelman- pair have been obtained by McCarthy et al. 2011) and the Two Micron All Sky 1. Reducing each image of the pair separately. Survey (2MASS, Skrutskie et al. 2006). Since both are 2. Computing the average of the results. relatively recent surveys, and the doubles we are However the Astrometrica software offers the pos- considering are wide and therefore probably with very sibility of combining all the images automatically and long periods, it is plausible to assume that the then performing the reduction. This option, ‘Track & astrometry obtained from our images and from the Stack,’ can be found in the Astrometry menu. The user catalogs should be similar. can choose among three possibilities for combining We compared the measurements we obtained the images of the same pair into a single image: using Astrometrica with the values of separation and Add: sums up the pixel values from individual position angle calculated from the coordinates given images. Before that, a pedestal is subtracted from the for each star in the SSDS-DR8 catalog. Table 3 shows

Table 3: Comparison of our measurement with SDSS-DR8 and 2MASS astrometry

Diff. with SDSS-DR8 Diff. with 2MASS astrometry astrometry Average Individual reductions (Angle) 0.20 0.19 ‘Track & Stack’ with add (Angle) 0.36 0.29 ‘Track & Stack’ with average (Angle) 0.27 0.32 ‘Track & Stack’ with median (Angle) 0.22 0.32 Average Individual reductions (Sep.) 0.05 0.06 ‘Track & Stack’ with add (Sep.) 0.07 0.04 ‘Track & Stack’ with average (Sep.) 0.04 0.03 ‘Track & Stack’ with median (Sep.) 0.06 0.03

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Six Proper Motion Pairs Measured with the 2-meter Faulkes Telescope North

the average of the absolute value of the difference of dence considering the given errors e1 and e2. The sec- the measurements in each case (angles in degrees, ond condition fixes a value of 50 mas/yr as the mini- separations in arc seconds). mum required for proper motion pairs. The third con- The table shows that the error (with respect to dition relates the separation and the proper motion. these surveys) in angle never exceeds 0.36 degrees, We have found that the two new pairs satisfy all the and that the error in separation is in all cases less criteria. than or equal to 0.07 arc seconds. This indicates the quality of the results. This range of errors is similar Two New Common Proper Motion to that among the professional surveys. For instance, Binaries in this case the average absolute value of the difference between the astrometry of 2MASS and SDSS- 05 42 00.85 +82 19 42.29

DR8 yields 0.20 degrees in the position angle and 0.04 This pair has a proper motion of about 150 milliseconds in separation. seconds of arc/year, and fulfills the criteria for the Regarding the method of reduction the results are movement of binaries established in Halbwachs not conclusive: the average of reducing individual im- (1986), which indicates that the movement of both ages seems the most accurate for obtaining the posi- components must exceed the 50 milliarcseconds of tion angle (0.20 and 0.19 degrees with respect to the arc/year. Using the RGB utilities included in Aladin two surveys), but the ‘Track & Stack’ average option we can observe the movement of the two stars as fol- provides more accurate results for the separation. lows: However, since the difference of the error in the sepa- 1. Launch Aladin. Click on File+Open. The ration is very small we have chosen the average of the server selector window opens. The Aladin im- individual measurements as the source of the results ages left-tab is selected by default. in Table 1. These results are somehow surprising be- 2. Enter the coordinates: 05 42 00.85 +82 19 cause it is usually assumed that it is better to first 42.29 and click on the SUBMIT button. This combine the images. Here we have found a counter shows a list of surveys that contain images for example. A possible explanation is that the individu- these coordinates. ally reduced images provide a cleaner point spread 3. Select the POSSI image sized 13'x 13', dated function and Gaussian profile and therefore contrib- 1955, and any of the POSSII images of the ute less error in the centroid that is ultimately gener- same size, dated either 1997 or 1999. This ated when the images are combined. Another possible gives an excellent timeline of about 42-44 explanation is that the images were only shifted by years. Click on SUBMIT. The two images are integer pixel amounts or that the sub-pixel sifting is loaded into Aladin's stack in the main window less than ideal. Future experiences with more images of the application. could help to clarify this issue. 4. Click on the rgb button of the main window. Halbwachs’ Criteria In the RGB image generator window, select one of the images in the red and the other one Given that we have found a new common mo- for instance in the blue plane. Click on Cre- tion faint double star, the question then is whether or ate. The result is a composition where most of not it is likely to be a binary star rather than an opti- the stars appear in white, except the new cal double (albeit likely two stars in the same general pair, which appears both in red and blue (see area). We used the criteria proposed by Halbwachs Figure 5). (1986) based on statistics. Halbwachs’ criteria are:

2 2 Next we show the data at different photometric (1) (µ1 - µ2) 2 < -2 (e1 + e2 ) ln (0.05) bands for the primary star in Table 4. (2) |µ1|, |µ2| ≥ 0.05 The first row in Table 3 corresponds to the Re- (3) ρ/ |µ |, ρ/|µ | < 1000 yr 1 2 vised (NLTT) Catalog (Salim & Gould, 2003), the second row to Lépine & Shara (2005), and the third row where µ1, µ2 are the two proper motion vectors in arc to the Two Micron All Sky Survey. According to the seconds/year, ei is the mean error of the projections on Cambridge Handbook of Space Astronomy and Astro- the coordinate axes of μ1, and ρ is the angular sepa- physics (page 71), the M stars verify V-J > 2.82 and J- ration of the two stars. The first condition checks if K between 0.89 and 1.15. Thus we can conclude that the hypothesis µ1 = µ2 is admissible with a 95% confi-

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Six Proper Motion Pairs Measured with the 2-meter Faulkes Telescope North

Table 4: Color indices in two bands.

Catalog V-J J-K NLTT 4.17 LSPM 0.89 2MASS 0.89

Figure 5: Red and blue stars reveal common proper motion over time.

the primary is likely an M star. The data available for the fainter secondary are not conclusive. 11 22 05.89 +01 28 03.63 This is a pair sharing proper movement over 110 milliseconds of arc/year, and it also fulfills the criteria established for binarity by Halbwachs (1986). In this case the photometry values found for both components suggest a K spectral type. The image in Figure 6 provided by the SDSS-DR7 (Abazajian et al. 2009) Figure 6: K spectral type components appear red on SDSS image. shows accordingly two red stars. Conclusions We found that the 2-meter Faulkes Telescope North on the summit of Haleakala is capable of meas- Acknowledgements uring faint double stars with accuracy comparable We thank the Las Cumbres Global Telescope Net- with SDSS and 2MASS. Our comparison of sepa- work for use of their 2-meter telescope on Haleakala. rately reducing a number of individual images with We also thank the University of Hawaii’s Institute for first stacking the images and then making a single Astronomy, Maui, for their support. We appreciate reduction suggested that for position angle, our indi- reviews of this paper by Thomas Frey and Vera vidual reductions were closer to SDSS and 2MASS, Wallen. This research made use of the ALADIN In- while for separation some were closer and others were teractive Sky Atlas and of the VizieR database of as- not. tronomical catalogs maintained at the Centre de Don- A disadvantage of the track and stack option is nées Astronomiques, Strasbourg, France, and the that one does not have an error (measurement preci- data products from the Two Micron All Sky Survey, a sion) estimate. Also, it is not easy to discard errant joint project of the University of Massachusetts and single measurements. On the other hand, it may be the Infrared Processing and Analysis Center/ less time consuming to use track and stack if the indi- California Institute of Technology, funded by the Na- vidual measurement option is not automated. tional Aeronautics and Space Administration and the National Science Foundation.

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Six Proper Motion Pairs Measured with the 2-meter Faulkes Telescope North

References Mason, B. D.; Wycoff, G.; Hartkopf, W. I., 2003, “The Washington Double Star Catalog”, http:// Abazajian, K. N.; Adelman-McCarthy, J, K.; Agüeros, ad.usno.navy.mil/wds/ M, A.; Allam, S. S.; Allende Prieto, C.; An, D.; Anderson, K. S. J.; Anderson, S. F.; Annis, J.; Reid, I. N.; Brewer, C.; Brucato, R. J.; Bahcall, Neta A.; and 194 coauthors, 2009, “The McKinley, W. R.; Maury, A.; Mendenhall, D.; Seventh Data Release of the Sloan Digital Sky Mould, J. R.; Mueller, J.; Neugebauer, G.; Phin- Survey”, The Astrophysical Journal Supplement, ney, J.; and 3 coauthors, 1991, “The second Palo- 182- 2, id. 543-558. mar Sky Survey”, Astronomical Society of the Pa- cific 103, 661-674. Adelman-McCarthy et al., 2011, “The SDSS Photometric Catalog, Release 8”, to be pub- Salim, S.; Gould, A., 2003, “Improved Astrometry and lished. Photometry for the Luyten Catalog. II. Faint Stars and the Revised Catalog”, The Astrophysi- Bonnarel, F.; Fernique, P.; Bienaymé, O.; Egret, D.; cal Journal, 582, 1011-1031. Genova, F.; Louys, M.; Ochsenbein, F.; Wenger, M.; Bartlett, J. G.; 2000, “The ALADIN Sinnott, R.W., 1984 “The virtues of the Hav- interactive sky atlas. A reference tool for identifi- ersine”, Sky & Telescope 68(159). cation of astronomical sources”, Astronomy and Skrutskie, M. F.; Cutri, R. M.; Stiening, R.; Astrophysics Supplement, 143, p.33-40. Weinberg, M. D.; Schneider, S.; Carpenter, J. M.; Caballero, R., 2012, “351 New Common Proper- Beichman, C.; Capps, R.; Chester, T.; Elias, J.; Motion Pairs from the Sloan Digital Sky Survey.” and 21 coauthors, 2006, “The Two Micron All Sky Journal of Double Star Observations, 8, p.58-70. Survey (2MASS)”, The Astronomical Journal, 131 (2), 1163-1183. Halbwachs, J.L., 1986, “Common proper motion stars in the AGK3”. Bull. Inf. Centre Donnees Stel- Zacharias N., Monet D.G., Levine S.E., Urban S.E., laires, 30, p.129. Gaume R., Wycoff G.L., 2005, “Naval Observatory Merged Astrometric Dataset (NOMAD)”, San Lépine, Sébastien; and Shara, Michael M. 2005, “A Diego AAS Meeting, January (2005). Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" ”. The Astronomical Journal, Volume 129, Issue 3, pp. 1483-1522.

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Comparison of Visual Data Collection Techniques on Mizar: The Barlow Lens

Holly Bensel, Nolan Peard, Dashton Peccia, David Scimeca

St Mary's School Medford, Oregon

Abstract: Since turning their eyes to the heavens and gazing at the celestial bodies therein, mankind has been restricted and limited in his knowledge of the cosmos by the resolving power of first, the naked-eye, and later, the telescope. It has been the goal of astronomers worldwide to create larger and more powerful telescopes with higher resolving capabilities. Such large telescopes are not an option, however, for amateur astronomers and as such they must rely on other instruments and tools to achieve greater precision. One of these tools is the Barlow lens, used to increase the magnification power of a telescope by increasing its focal length. This magnification can assist in precision and accuracy of observations, especially when measuring the angular separation. Continuing their previous work in double star research (Bensel, Peard, Peccia, Scimeca, et al.), a contingent from St. Mary’s School in Medford, Oregon compared the usage of a 2X Barlow lens with their usual telescope configuration and discuss the advantages and disadvantages they experienced with each.

Introduction Double stars are defined into the following two separate categories: binary systems, in which the stars are close enough relative to each other to have significant gravitational interactions; and optical double stars, which are gravitationally unrelated stars that appear to be near each other when viewed from earth. Data collection and analysis over several centuries is necessary to determine in which category a double star belongs. This is accomplished through detailed measurements of separation and position angles of the stellar components within the system and the subsequent analysis of those measurements. The authors compared visual measurements of the known double star, Mizar, as part of a process to dis- Figure 1: St. Mary’s School Participants in the 2011 Pine Mountain cover an accurate and practical method for double Workshop. From left to right: Fred Muller, Holly Bensel, Dave Sci- star observation and research. meca, Robert Bensel, Dashton Peccia, and Nolan Peard

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Comparison of Visual Data Collection Techniques on Mizar: The Barlow Lens

This project is in continuation of the initial stud- recommended range. The time component is meas- ies carried out at the Pine Mountain Observatory ured by placing the calibration star on the Eastern Summer Science Research Workshop in 2009. During edge of the linear scale and allowing it to drift in 2011, the authors (Figure 1) continued the visual as- Right Ascension to the opposite side of the scale. The pect of double star research and added to their skill field drift is timed using a stopwatch to the near- set by comparing the use of a 2X Barlow lens with est .01 seconds. To reduce random errors, many trials their typical setup. It was the goal of this group to were made by different individuals from the club. The master the visual observing techniques on double average of all these trials was used to determine the stars and compare our visual data, with and without scale constant (Z) for the telescope eyepiece system. the additional 2X Barlow lens, with previously pub- (Z) is defined as follows: lished data. The location for these observations, Pine T 15.0411 cos(δ ) Mountain Observatory, is positioned at 43.8 N lati- Z = ave RS tude and 120.9 degrees W longitude at an elevation of D 6500 feet above sea level near Bend, Oregon. The dry, desert-like climate and dark skies in that area make where Z is the scale constant (in arc seconds per divi-

for excellent viewing. sion), Tave is the average drift time, 15.0411 is the arc seconds per second of the Earth’s rotation at the ce- Hypothesis lestial equator, cosδRS is the cosine of the reference Due to adverse weather conditions and resulting star’s declination, and D is the number of divisions on vibrations in the telescope, it was thought that the the linear scale which, for our Celestron eyepiece, is visual data gathered in standard setup, sans Barlow 60 divisions. Because two different telescope setups lens, would provide more accurate results when com- were being used, the scale constant had to be meas- pared to the published results in the WDS Catalog ured both with and without the 2X Barlow lens. The (2010) than the data taken with the augmenting 2X data used in the calculations for each scale constant is Barlow lens. Although it was initially believed that discussed below. the use of a 2X Barlow lens might allow more accu- The reference star used in the calculation, Mizar, rate measurements of the separation of Mizar, blus- had an average drift time of 47.64 seconds (standard tery conditions caused severe field vibration reducing deviation of 0.31s and mean error of 0.01s) with a the precision and possibly the accuracy of the obser- standard setup and 20.42 seconds (standard deviation vations. of 0.24s and mean error of 0.08s) when the 2X Barlow Equipment lens was introduced. This resulted in a scale constant of 6.85 and 2.93 arc seconds per division with and The group used a Meade 10” LX200 Schmidt- without the Barlow lens, respectively. Data for the Cassegrain telescope, generously donated by Fred scale constant determination using the Celestron Mi- Muller in 2007. In the 2011 observing season a cro Guide eyepiece both with and without the addi- 12.5mm Celestron Micro Guide astrometric eyepiece tional Barlow lens is shown in Table 1 below. was used in addition to a 2X Barlow lens. The telescope was converted from Alt-Az to equatorial mode Separation Measurement of Mizar in 2010 through the use of a wedge bought with dona- The separation angle between adjacent stars is tions. determined by aligning the primary and secondary Calibration of the Celestron Astromet- star along the linear scale and measuring the distance between them to the nearest 0.1 division. The ric Eyepiece pair of stars is reallocated across the scale to decrease The first step in observing double stars is to cali- bias between trials. This value is then multiplied by brate the linear scale on the astrometric eyepiece in the scale constant (Z) to obtain the separation angle units of arcseconds per division. Argyle (p. 152) sug- in arc seconds (Argyle p. 152). gests using a reference star of medium brightness at a Mizar was chosen for this project because it is an declination between 60o and 75o to avoid timing er- extensively studied double star with known separa- rors. If the star is below 60o then the field drift is too tion and position angle measurements. It was also slow, and above 75o is too fast to allow accurate tim- easily located in the night sky at Right Ascension 13h ing. Therefore, the club used Mizar, at 54o 55.51’ dec- 23.6’, declination 54° 55.31’. The Washington Double lination because it was easily visible and near to the Star (WDS) Catalog (2011) cited the separation dis-

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Comparison of Visual Data Collection Techniques on Mizar: The Barlow Lens

Table 1: Measurements for scale constant determination (using Mizar) without and with the Barlow lens.

Scale Const. Epoch (B1900) #Obs Time (sec) STDEV Mean Error (a.s. per div.)

w/out Barlow 2011.57 10 47.64 0.31 0.01 6.85

with Barlow 2011.57 10 20.42 0.24 0.08 2.93

Table 2. Separation angle measurements of Mizar (STF1744) without and with the Barlow lens.

Epoch Lit. Epoch #Obs SD/ME Obs. Sep. Lit. Sep. % Error (B1900)

w/out Barlow 2011.56 2011 10 0.44/0.14 14.59 14.7 ~0.75%

with Barlow 2011.56 2011 10 0.42/0.13 15.25 14.7 ~3.72%

Table 3: Position angle measurements of Mizar (STF1744) without and with the Barlow Lens.

Epoch Lit. Epoch #Obs SD/ME Obs. PA Lit. PA % Error (B1900)

w/out Barlow 2011.56 2011 5 0.61/0.27 152 152 ~0.0%

With Barlow 2011.56 2011 10 1.79/0.57 153.9 152 ~1.25%

tance and position angle as 14.7 arc seconds and 152o Conclusions and New Directions: respectively. The results of separation angle measure- In measuring the position and separation angles ments of Mizar using the Celestron eyepiece without of the primary components of Mizar, a quadruple star and with the additional Barlow lens are shown in Ta- system, the authors discovered that measurements ble 2. acquired without the use of a 2X Barlow lens were Position Angle Measurement of Mizar: more accurate, when compared to literature values in the WDS, than those made with the Barlow lens. Spe- In the equatorial arrangement, the primary star cifically, there was a 2.97% increase in error when the was placed at the center of the linear scale using the Barlow lens was used in measuring the separation telescope controller keypad, the eyepiece rotated so angle and a 1.25% increase in error for measuring the that the double star was aligned with the linear scale. position angle (Tables 3, 4, 5, 6). The authors believe The Right Ascension motor was then deactivated and that this unexpected increase in error was a result of the position angle determined by observing which de- a higher propensity toward field vibration, resulting gree marking the primary star crossed on the outer from air flux and occasional jostling by the operators, protractor scale, rounding to the nearest 0.5o. Once while using the 2X Barlow lens. Although a higher the star crossed the protractor scale, the tracking mo- level of precision and accuracy was expected, extreme tor was reactivated, the star brought back to center, care must be taken to eliminate vibrations else the and the procedure repeated with the reticule rotated use of a Barlow lens may be nullified. The authors 180 degrees every five trials to reduce operator bias. recommend that a Barlow lens will be most useful on The results of position angle measurements of Mizar very still, clear nights with an established procedure using the Celestron eyepiece without and with the and experienced operators. Lacking those parameters, additional Barlow lens are shown in Table 3. the relatively equivalent level of accuracy and preci-

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Comparison of Visual Data Collection Techniques on Mizar: The Barlow Lens

sion can be achieved without any augmenting optics References such as the Barlow lens. 1. Argyle, Robert, Observing and Measuring Visual Acknowledgments Double Stars, Springer, London, 2004. The authors would like to thank Russell Genet, 2. Holly Bensel, et al., "Comparison of Data on Iota Dr. Rick Watkins, and Tom Frey for providing the Bootes Using Different Telescope Mounts in 2009 workshop which provided the experience needed to and 2010." Journal of Double Star Observations accomplish their research. We want to thank Pine 8.1 (2012): 54-57. Journal of Double Star Observa- Mountain Observatory for opening the observatory for tions. University of South Alabama, 1 Jan. 2012. the workshops and providing facilities and equip- . ment. We also thank Fred Muller for donating the telescope and Dave Scimeca for donating his time and 3. Frey, Thomas G., October 2008, Journal of Double expertise. Acknowledgement is also directed to the Star Observations, 3(2), p. 59-65. faculty and staff of St. Mary’s School for providing 4. Frey, Thomas G., October 2009, Journal of Double facilities and financial support to the authors and the Star Observations, 5(4), p. 212-216. St. Mary’s Astronomy Club. 5. Mason, Brian. The Washington Double Star Cata- log. July 2009. Astrometry Department, U.S. Na- val Observatory. .

Holly Bensel is a science teacher at St. Mary’s School in Medford, Oregon. Fred Muller is a retired science teacher and occasionally acts as a substitute teacher at St. Mary’s School. Dave Scimeca is a retired technician from the Ames Research Center. Nolan Peard and Dashton Pec- cia are accomplished students at St. Mary’s School in Medford, Oregon.

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Journal of Double Star Observations The Journal of Double Star Observations (JDSO) January 1, 2013 publishes articles on any and all aspects of astronomy in- Volume 9, Number 1 volving double and binary stars. The JDSO is especially interested in observations made by amateur astronomers. Editors Submitted articles announcing measurements, discover- R. Kent Clark ies, or conclusions about double or binary stars may un- Rod Mollise dergo a peer review. This means that a paper submitted Editorial Board by an amateur astronomer will be reviewed by other ama- Justin Sanders teur astronomers doing similar work. Michael Boleman Not all articles will undergo a peer-review. Articles Advisory Editor that are of more general interest but that have little new Brian D. Mason scientific content such as articles generally describing

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