Professor Comet Report

may 2010

Current status of the predominant comets for 2010

Comets Designation Orbital Magnitude Trend Observation Visibility (IAU(IAU(IAU-(IAU --- Status (Visual) (Lat.) Period MPC) McNaught 2009 R1 C 8 Bright 50° N - 45°S Early Morning McNaught 2009 K5 C 8.5 Fading 55°N - 15°N All night Machholz 2 141P PPP ~10 Steady Elongation N/A Status: Poor Wild 2 81P PPP 10.5 Fading 55°N – 75°S All Night Tempel 2 10P PPP 11.5 Bright 45°N - 75°S Morning Christensen 2006 W3 C 12 Fading 30°N – 90°S Best Morning Vales 2010 H2 PPP 12 Possibly 55°N – 55°S Best Fading Evening Wolf – 43P PPP Possibly Bright Conjunction N/A Harrington 12 Gunn 65P PPP 12.5 Steady 30°N – 85°S Morning Schwassmann 29P PPP Possibly Varies 50°N - 45°S Early – Wachmann 13 Evening Siding Spring 2007 Q3 C 13 Fading 65°N – 5°S All Night Catalina 2009 O2 C 13.5 Fading Poor N/A Elongation P/Hill 2010 A3 PPP 14 Fading 45°N - 5°S Early Evening

The red designation is assigned to all comets that are of 12 th visual magnitude or brighter and are classified as the majormajor comets ... All remaining comets that are possibility at 12 th visual magnitude or fainter are given the blue designation and are classified as the minor comets!

1 C/2009 R1 (McNaught)

This comet could possibly become the great comet of 2010 as reports coming in from comet observers now indicate an 8 th visual magnitude brightness of this comet. R1 has just left solar conjunction and initial reports indicate that the comet is brighter than what was expected and continues to get brighter throughout the months of May and thru June. R1 is rapidly getting brighter at an ever increasing rate as it reduces its distance between itself and both the and . However the absolute brightness for this comet increases at an ever slower rate. Right now it is visible between the Eastern edge of the great square of Pegasus and the Eastern Fish of during the early morning hours of late spring before sunrise. Based on MPC data, this comet is expected to reach 5 th visual magnitude by late June and a maximum brightness of 4.7 during the period 3 – 8 July. However, an analysis of the light curve indicates that this comet could reach a visual magnitude range of 2 – 3, but the comet is moving eastward across the sky and enter back into solar conjunction!

Currently the comet can be located between the Northeast edge of the great square of Pegasus and the Eastern Fish of Pisces during late May. As of 24 May the comet is positioned between Epsilon and Zeta Andromedae at a current distance from Earth of 1.3955 AU and a solar distance of 1.0154 AU. This means that the comet is technically now as close to the Sun as Earth is in its mean distance from our home , but still above the plane of the . The comet will move in a general NE direction passing north of Tau Piscium during the early morning hours of 28 May. The comet will move along the southern edge of Andromeda passing a few degrees to the SE of both Mirak ( β Andromedae) and Almach ( γ Andromedae) during the period of 28 May thru 6 June. All the while the comet will have reached a distance form Earth of 1.1823 AU and a solar distance of 0.7645 AU at an expected 7.2 visual magnitude. The comet will graze to the South of the spiral NGC 891 during the evening hours of 7 June.

R1 will fly past Andromeda and move towards Perseus during early thru mid June. It will be about 2° to the NW of the open NGC 1039 by mid day of 9 June moving in a NE direction towards the northern region of Perseus. The comet will pass to the south of Melotte 20 which houses Mirfak ( α Persei) during mid June. The comet will graze by Delta Persei to its SE and then head out of the Perseus and move into Auriga by late June with a solar elongation of only 27° by 20 June! The comet will move in

2 an easterly direction to the north of Capella and then head south again towards the Sun for another solar conjunction. R1 McNaught will occult Castor at an expected visual magnitude of 4.8 during the evening hours of 4 July EDT, but it will be at a paltry solar elongation of 13° and not visible to astronomers during the mid summer. During this whole period from late June thru mid July, R1 will turn more southerly towards the ecliptic as it moves out of Gemini towards the Western edge of Cancer. All this is happening as it approaches the ecliptic while obtaining its perihelion during the time in which it will be at maximum brightness!

IAU MPC Ephemeris data for C/2009 R1: Date TT RA(2000) Decl. Delta r Elong. Phase m1 m2 2010 05 24 00 38.69 +25 48.9 1.408 1.026 46.7 45.9 8.9 2010 05 29 01 04.06 +31 03.2 1.311 0.932 45.1 50.3 8.3 2010 06 03 01 37.04 +36 37.2 1.230 0.837 42.5 54.9 7.7 2010 06 08 02 20.73 +42 01.6 1.171 0.742 38.8 59.1 7.0 2010 06 13 03 17.79 +46 19.9 1.139 0.647 34.4 62.3 6.4 2010 06 18 04 26.49 +48 14.0 1.139 0.558 29.3 63.0 5.7 2010 06 23 05 37.00 +46 44.8 1.171 0.480 24.0 59.6 5.2 2010 06 28 06 36.84 +42 00.7 1.231 0.424 18.8 50.7 4.7 2010 07 03 07 20.69 +35 08.7 1.305 0.405 14.2 37.9 4.7 2010 07 08 07 50.73 +27 30.3 1.382 0.430 10.9 26.7 5.0 2010 07 13 08 11.73 +20 04.7 1.454 0.489 10.3 21.9 5.7

NoteNote:: See ephemeris data terminology below .

Date: Month and using the standard Gregorian calendar.

TT: Terrestrial Time (Day of the Month) as a substitute for the astronomical Julian date.

RA(2000): based on the J2000 (longitudinal coordinate for the celestial sky) measured in hours and minutes.

Decl.: as measured in degrees and arcminutes.

Delta: The distance from Earth measured in AUs (1 AU = 1 = 92 955 807 mi = 149 597 871 km as the mean distance between the Earth and Sun).

R: The solar distance as measured in AUs.

Elong: Solar elongation which is the angle of separation between the observed object and the Sun as measured across the night sky as measured in degrees.

Phase: Phase angle between the Sun, the celestial object, and the observer on the surface of the Earth. Also known as the Sun – Object – Observer angle. m1: The visual magnitude of the celestial object as observed on the surface of the Earth at sea level. m2: The nuclear magnitude which is the visual magnitude of the false nucleus within the coma as seen by an observer here on Earth at sea level.

3 C/2009 K5 (McNaught)

This is another of McNaught’s comets that is currently well positioned in the northern hemisphere for late spring. It is currently being reported as a well condensed smudge in a good pair of binoculars when seen in fairly dark skies. K5 is believed to have reached a maximum brightness of 7.9 visual magnitude during the earlier part of May is expected to stay in the 8 – 9 range for into the first few days of June. After that it will continue to fade towards 10 – 11 visual magnitude range thru early June and then dim to 12 th magnitude before 18 July while still observable in the northern hemisphere while low in the night skies.

K5 McNaught as of 24 May is at the northern edge of the region of Cepheus having past through the main body of that constellation last month. It will move thru a line of stretching from HD 30338 which is a K3III star to HD 268326 and ending at HD 25007 with a spectral classification of G8III + A6V. The stars have a visual magnitude of 5.07, 5.43, and 5.10 respectfully and crossing this line of stars during the evening of 24 May while moving to the ESE. The comet will then turn south heading towards and will stay within eastern region of the constellation until mid July. To find the comet in northern area of Camelopardalis, look for a ‘broken – T’ shaped asterism of stars centered on HD 34351 which has a spectral type F0 at a visual magnitude of 6.74. The comet will pass just over half a degree during the late afternoon of 28 May and during that same night the comet will have to the north of HD 35783. It has the spectral type F8 at a visual magnitude of 7.69 and represents the eastern edge of the broken – T asterism.

The comet will move through many non – distinguishing stars during early June, but can be found on average about 1 hr of RA to the east of open cluster Collinder 464 through early June while moving in a more SE direction. During the early morning hours of 15 June K5 can be spotted about 1.8° to the NNE of 43 Camelopardalis. The star has a spectral classification of B7III with a visual magnitude of 5.12. K5 eventually will cross the northern constellation boundary with Lynx during the late afternoon/early evening of 13 July. Expect McNaught to continue moving southward along the eastern region of Lynx and will be within ~1.65° to the east of 27 Lyncis by 6 September with a solar elongation of 57°. By late summer K5 McNaught will dim down to a visual magnitude of 13.2 at a solar distance of 2.6706 AU and a distance from Earth of 2.2765 AU.

4 IAU MPC Ephemeris data for C/2009 K5: Date TT RA(2000) Decl. Delta r Elong. Phase m1 m2 2010 05 24 04 24.73 +81 26.8 1.660 1.464 60.8 37.2 10.3 2010 05 29 05 34.20 +78 44.5 1.749 1.482 57.8 35.4 10.4 2010 06 03 06 12.76 +75 52.9 1.838 1.504 54.8 33.5 10.6 2010 06 08 06 37.02 +73 09.9 1.927 1.528 52.0 31.5 10.8 2010 06 13 06 53.97 +70 40.2 2.015 1.555 49.3 29.6 10.9 2010 06 18 07 06.75 +68 24.2 2.099 1.585 46.7 27.8 11.1 2010 06 23 07 16.94 +66 21.2 2.179 1.617 44.4 26.1 11.3 2010 06 28 07 25.39 +64 29.9 2.255 1.652 42.3 24.5 11.4 2010 07 03 07 32.63 +62 49.2 2.325 1.688 40.6 23.1 11.6 2010 07 08 07 38.95 +61 18.1 2.390 1.726 39.2 21.8 11.8 2010 07 13 07 44.56 +59 55.6 2.449 1.765 38.1 20.8 11.9 2010 07 18 07 49.58 +58 40.9 2.502 1.806 37.6 20.1 12.1

5 141P/Machholz 2

The apparition of this comet is bad while the brightness level is steady with the last recorded visual magnitude value of 11.3 back in late April. So far no further observations have been reported and none is expected for the rest of the year. Machholz 2 is currently moving directly eastwards through the constellation of Aries with a solar elongation of 16° as of 24 May with a solar distance of 0.7627 AU and at a distance from Earth of 1.6815 AU. It now located only during the daytime and its solar elongation will reduce to 4.8° by 3 July to 19.8° by 16 September, so do not expect to see it for all of summer 2010. Interesting note that on 2 June between midnight and 1 am EDT, Machholz will be located about 1.743° to the south of Merope (the southern most star of the Pleiades). The comet will move thru the winter hexagon during the summer; first across Taurus during the month of June and then move across and just north the ‘top – of – the – club’ of Orion ( χ1 & χ2 Orion) during the last week of June. Expect the comet to move across southern Gemini until late July, thru southern region of Cancer into late August, and reaching the NW region of the constellation of Sextans by early September.

IAU MPC Ephemeris data for C/2009 K5: Date TT RA(2000) Decl. Delta r Elong. Phase m1 m2 2010 05 24 02 51.77 +20 29.5 1.679 0.764 16.5 22.1 9.6 19.1 2010 05 29 03 21.23 +21 33.8 1.698 0.758 14.2 19.2 9.5 19.0 2010 06 03 03 50.66 +22 17.5 1.723 0.761 12.1 16.2 9.6 19.0 2010 06 08 04 19.69 +22 40.7 1.753 0.774 10.1 13.3 9.9 18.9 2010 06 13 04 47.99 +22 44.5 1.787 0.796 8.3 10.6 10.3 18.9 2010 06 18 05 15.30 +22 30.6 1.825 0.825 6.9 8.5 10.8 19.0 2010 06 23 05 41.40 +22 01.4 1.866 0.861 5.8 6.8 11.4 19.0 2010 06 28 06 06.17 +21 19.3 1.910 0.902 5.1 5.7 12.1 19.1 2010 07 03 06 29.58 +20 26.8 1.957 0.948 4.8 5.2 12.8 19.3 2010 07 08 06 51.61 +19 26.1 2.006 0.997 4.9 5.0 13.5 19.4 2010 07 13 07 12.31 +18 19.3 2.057 1.048 5.2 5.0 14.2 19.6 2010 07 18 07 31.73 +17 08.0 2.108 1.101 5.6 5.2 14.9 19.8 2010 07 23 07 49.97 +15 53.5 2.161 1.156 6.1 5.4 15.6 19.9

6 81P/Wild 222

Currently Wild 2 has faded to about 10 th visual magnitude and it is in a good position in the sky to be visible at brightness values about 13 until late July and then dim down to 16 th visual magnitude by 26 October. The comet is presently located in the eastern region of Virgo and is undergoing retrograde motion and is expected to continue in such motion until mid June. On 19 June in the morning early hours before sunrise Wild 2 will be just a little over 2° to the south of Syrma (Iota Virginis) as it leaves its retrograde motion. On that date the solar distance for Wild 2 will be 1.9528 AU while at a distance from Earth of 1.1697 AU with a solar elongation of 126°. The comet will pass the Western boundary of the region for the constellation of the daytime of 25 June. Expect the comet to pass a line between Xi 1 Librae and Mu Librae by 23 July with an angular separation of ~2.6° between the two stars as the comet will be about 2/3 of that gap from Mu Librae.

The solar elongation of the comet will have decreased to 104° on 23 July with a solar distance 2.1397 AU and a distance from Earth of 1.6556 AU with a visual magnitude 13.1. Wild 2 will move thru Libra during the month of August and will move about 1/3° to the north of Omicron Librae and will have dimmed to visual magnitude 13.8 before dawn on 13 August. Omicron Librae has a spectral type F0III at a visual magnitude 6.30 and a closer star halfway to Wild 2 on that day is HD 136406 a K0 class star about a magnitude fainter than o Librae. 81P will move about 0.59° to the north of Zeta 3 Librae during the late afternoon/evening of 19 August. The comet will have faded to 14 th visual magnitude with a reduced solar elongation while moving further away from both the Earth and the Sun at distances further away than Mars is from the Sun!

IAU MPC Ephemeris data for 81P/Wild 2: Date TT RA(2000) Decl. Delta r Elong. Phase m1 m2 2010 05 24 14 03.34 -05 26.5 0.888 1.825 147.4 17.4 10.7 19.0 2010 05 29 14 04.46 -05 49.2 0.934 1.847 143.1 19.2 10.8 19.2 2010 06 03 14 06.21 -06 15.8 0.983 1.871 139.0 20.8 11.0 19.3 2010 06 08 14 08.57 -06 45.6 1.036 1.895 135.0 22.2 11.2 19.5 2010 06 13 14 11.51 -07 18.2 1.093 1.920 131.2 23.5 11.4 19.7 2010 06 18 14 15.01 -07 53.2 1.153 1.946 127.5 24.5 11.6 19.9 2010 06 23 14 19.02 -08 30.1 1.216 1.972 123.9 25.3 11.8 20.1 2010 06 28 14 23.50 -09 08.3 1.281 1.998 120.4 26.0 12.0 20.2 2010 07 03 14 28.41 -09 47.6 1.349 2.025 117.0 26.6 12.2 20.4 2010 07 08 14 33.70 -10 27.6 1.420 2.052 113.7 27.0 12.4 20.5 2010 07 13 14 39.35 -11 07.9 1.493 2.080 110.5 27.2 12.6 20.7 2010 07 18 14 45.32 -11 48.4 1.568 2.108 107.4 27.4 12.8 20.8 2010 07 23 14 51.60 -12 28.7 1.645 2.136 104.3 27.5 13.0 21.0 2010 07 28 14 58.14 -13 08.6 1.724 2.164 101.2 27.4 13.2 21.1

7 10P/T10P/Tempelempel 2

Tempel 2 is already visible in the night skies of the northern hemisphere and it is rapidly getting brighter in the morning hours before dawn. Right now the comet is expected to reach 9 th visual magnitude by the beginning of June if it has not reached it already. The comet should reach a maximum visual magnitude of 8.1 during the time period 13 – 28 July and will be approaching the Sun with a solar distance of 0.674 AU expected by 2 August and Tempel 2 should reach perigee during the time period 3 – 8 July at a distance of 1.423 AU. The comet is currently located in between Sadalsuud ( β Aquarii) and θ Aquarii in the NW region of that constellation during late May. Tempel 2 is moving east towards θ Aquarii and will near occult or graze the G8III-IV star of visual magnitude 4.16 during the period just after midnight on the night of 1 June.

Expect the comet to fly eastward across northern half of Aquarius for most of the month of June as it is getting brighter and is expected to stay in the 9 – 10 magnitude range well into Autumn 2010. The star will move about 1/2° to the north of in the mid – afternoon of 12 June. As it continues eastward it will fly ~0.85° to the north of Phi ( Φ) Aquarii on the evening of 19 June at a solar elongation of 102°. Continuing eastward, Tempel will across the constellation boundary between Aquarius and Cetus the early morning of 4 July with the only bright star 30 Piscium at visual magnitude 4.41. This star has a spectral type of M3III and the comet will be located ~1.77° to the SW of 30 Piscium. The comet move nearly 1° to the south of 30 Piscium the early morning of 6 July. Next to 30 Piscium is the star which is a special K0III type star at a visual magnitude of 4.61. Expect the comet to move ~1 1/3° to the south of 33 Piscium during the early morning hours of 7 July. 10P/Tempel 2 will move into the constellation region of Cetus and stay there while undergoing retrograde motion for the remaining duration of 2010. All the while Tempel 2 is getting brighter and approaching perihelion for the most of July and maintaining brightness above 10 th magnitude well into September.

8 IAU MPC Ephemeris data for 10P/Tempel 2: Date TT RA(2000) Decl. Delta r Elong. Phase m1 m2 2010 05 24 21 51.79 -08 31.2 1.001 1.489 95.4 42.6 9.3 17.0 2010 05 29 22 07.00 -08 06.7 0.962 1.475 96.5 43.1 9.1 16.9 2010 06 03 22 22.29 -07 44.3 0.926 1.462 97.6 43.4 9.0 16.8 2010 06 08 22 37.59 -07 24.8 0.893 1.451 98.8 43.7 8.8 16.7 2010 06 13 22 52.84 -07 08.9 0.862 1.441 100.0 43.9 8.6 16.7 2010 06 18 23 07.98 -06 57.2 0.834 1.434 101.2 44.0 8.5 16.6 2010 06 23 23 22.94 -06 50.2 0.807 1.428 102.5 44.0 8.4 16.5 2010 06 28 23 37.63 -06 48.5 0.784 1.425 103.9 43.8 8.3 16.4 2010 07 03 23 51.97 -06 52.5 0.762 1.423 105.3 43.6 8.2 16.4 2010 07 08 00 05.84 -07 02.8 0.742 1.423 107.0 43.1 8.2 16.3 2010 07 13 00 19.14 -07 19.8 0.725 1.425 108.7 42.5 8.1 16.2 2010 07 18 00 31.76 -07 43.5 0.709 1.429 110.6 41.7 8.1 16.2 2010 07 23 00 43.59 -08 14.0 0.696 1.435 112.7 40.8 8.1 16.1 2010 07 28 00 54.54 -08 51.2 0.684 1.443 114.9 39.6 8.2 16.0 2010 08 02 01 04.50 -09 34.8 0.674 1.453 117.3 38.3 8.2 16.0

C/2006 W3 (Christensen)

Christensen is well to the South in the southern region of Sagittarius and fading towards 12 th visual magnitude from many field reports despite the predictions of the MPC. The comet will be between Rukbat ( α Sagittarii) and

Arkab Prior/Posterior ( β1 and β2 Sagittarii respectfully) the afternoon of 14 July. Christensen will move SW into Corona Australis the mid – morning of 17 June and then cross into the constellation region of Telescopium the mid – morning of 30 June. Eventually this comet will likely have faded to a visual magnitude of 14 before the end of the month of June.

IAU MPC Ephemeris data for C/2006 W3 (Christensen): Date TT RA(2000) Decl. Delta r Elong. Phase m1 m2 2010 05 24 19 55.60 -37 44.6 3.663 4.350 127.2 10.7 14.2 2010 05 29 19 49.42 -38 54.3 3.629 4.381 132.7 9.8 14.2 2010 06 03 19 42.49 -40 03.2 3.604 4.412 138.2 8.8 14.2 2010 06 08 19 34.86 -41 10.3 3.587 4.443 143.4 7.8 14.3 2010 06 13 19 26.56 -42 14.5 3.579 4.475 148.2 6.9 14.3 2010 06 18 19 17.68 -43 14.8 3.581 4.506 152.4 6.0 14.3 2010 06 23 19 08.32 -44 10.2 3.593 4.538 155.6 5.3 14.3 2010 06 28 18 58.61 -44 59.8 3.615 4.570 157.3 4.9 14.4 2010 07 03 18 48.71 -45 43.2 3.648 4.602 157.3 4.9 14.4 2010 07 08 18 38.77 -46 20.0 3.690 4.634 155.5 5.2 14.5 2010 07 13 18 28.95 -46 50.1 3.742 4.667 152.3 5.8 14.6 2010 07 18 18 19.41 -47 13.7 3.804 4.699 148.3 6.5 14.6 2010 07 23 18 10.31 -47 31.3 3.875 4.732 143.7 7.3 14.7 2010 07 28 18 01.74 -47 43.4 3.953 4.764 138.8 8.1 14.8

9 P/2010 H2 (Vales(Vales))))

P/2010 H2 (Vales) is located in the eastern region of Virgo forming a triangle and lying halfway between Minelauva ( δ Virginis) and Heze ( ζ Virginis). Just go halfway between the two 3.4 visual magnitude stars and go 2° to the NE to find the comet which is currently brighter than 12 th magnitude. The coma is expanding and is now at 2 arcmin in size and will continue to expand rapidly during the month of June. The comet will move SSW between the two stars and then make a turn towards the SE at the beginning of July. Vales will be far to the south of Heze by late July and nearly 1 1/3° to the north of 80 Virginis a spectral type G6III star at visual magnitude 5.73 the evening of 26 July. The comet will remain in Virgo will into early September grazing ~0.37° of Kappa Virginis the late morning of 3 September.

IAU MPC Ephemeris data for P/2010 H2 (Vales): Date TT RA(2000) Decl. Delta r Elong. Phase m1 m2 2010 04 24 13 33.48 +04 47.7 2.150 3.117 160.8 6.1 12.6 2010 05 04 13 26.64 +04 37.6 2.194 3.121 152.1 8.7 12.6 2010 05 14 13 21.04 +04 13.2 2.262 3.125 142.5 11.4 12.7 2010 05 24 13 17.12 +03 34.8 2.351 3.129 132.8 13.7 12.8 2010 06 03 13 15.13 +02 44.1 2.458 3.134 123.5 15.7 12.9 2010 06 13 13 15.11 +01 42.8 2.578 3.140 114.6 17.1 13.0 2010 06 23 13 17.00 +00 32.9 2.709 3.146 106.1 18.1 13.1 2010 07 03 13 20.65 -00 43.7 2.846 3.153 98.0 18.6 13.3 2010 07 13 13 25.89 -02 05.5 2.987 3.160 90.3 18.8 13.4 2010 07 23 13 32.55 -03 31.2 3.130 3.168 82.8 18.6 13.5

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