The Objective View July 1998 Newsletter of the Northern Colorado Astronomical Societv

Thom Peck.President 962-9695 [email protected] Randy Moenclu V Pres 493-7613 [email protected] Doug MoencfuTreasurer 221,-9455 [email protected] Tom Teters, Secretarv 482-5702 [email protected] Randy Moench, Web Site Editor WVVWPage: http: / / lamar.colostate.edu/ -rmoench/ ncasrdm.html David Chamness,A L correspondent 482-1794 Dan Laszlo, Newsletter Editor 498-9226 [email protected]

Meetings first Thursday of each Month Next Meeting: JuIy 2 7:30 pm Discovery Center, Fort Collins " Supernovae " by Dave Chamness ** Club Businesswill precede the program, 7-7:30pm n*

July 2 NCAS Meeting Directions June 4 Program: Famous Astronomers, from Tycho Brahe Discovery Center, 703E ProspectRd, Fort Collins as the Man with the Golden Nose, to Jocelyn Bell and the From Loveland go North on US 287 to ProspectRd in Fort Little Green Men, by Ken Van Lew Collins, go East about 0.5 miles. Look for the Discovery Tycho Brahe was a flamboyant L6th century nobleman Center sign on the South side of the street. who piqued his contemporaries with new notions. He From I-25, take Exit 268, head West into Fort Collins. documented Supernova 1572, challenging the prevailing Continue past Lemay Ave about 0.5 miles and see the Aristotelian view that the heavens were perfect and Discovery Center on the left. unchanging. Not one to back down graciously,a duel with a student over a mathematical problem cost him his nose. NCAS Party, July 18 or 25, Stove Prairie Site He wore a gold or silver replacement thereafter. The From the Stove Prairie School go 1.1 mile west and bear Danish king gave him the island of Hven to establish west(right) after the fence for a tenth or two. Tom will Uraniborg, his "sky castle." There he cataloged put out the star party sign on the left side of that road. positional measurements for . This data became a You can call 482-5702if the weather is in doubt. The point of contention with the reclusive fohannes Kepler, Stove Prairie School intersection is 13 miles west from who needed the figures to develop his views on Bellvue and over the Rist Canyon Road, while in place planetary motion. Tycho allegedly died as a consequence this is a steep road, the county takes VERY good care of of his lifestyle, suffering a ruptured bladder rather than it. If you're coming from the Loveland area use the leave the king's table at a royal banquet. Kepler was a Masonville Road, the S.P.S. is L4 miles from the misfit in Brahe's court. He inherited Brahe's data after Masonville intersection. The site itself is at about 7500ft, years of refusal. Kepler revolutionized astronomy with 3 it has a good open horizon (5*-10*), but not cacti or laws. He 1) determined that orbits are ellipses,that 2) a services. So bring warm clothes, several layers. Be planet's speed in its orbit varies, and a line from Sun to prepared!!! This site is allowed us through the auspices planet sweeps through a constant area for any specified of the land manager/owner, he wanted us to CALL before time interval. His 3rd law states that for all the we went up there and asked that we leave the site clean planets, (period) squared / (mean orbit radius) cubed : a and in the same condition as we found it. Tom Teters constant. Eratosthenes was a Greek who lived in Alexandria Egypt. He derived the Earth's NCAS Events, from Randy Moencll Vice President circumference,based on the legend of the well of Syene. August 6 Human SpaceMissions Eligar Sadeh It was noted that on 1 day of the , the Sun's Moon/Mars Synergies reflection could be seen in the well; this meant that the September3 Gravity Waves Bill Massman Sun was straight overhead. He then measured the angle of the noontime shadow in Alexandria on this day, Other FRASC Events which was 7 degrees. Thereforg the distance from Syene Longmont Astronomical SocietyMeetings to Alexandria was 7 1360 of the Earth's circumference, 7:30 pm, Third Thursday, monthly and he computed a value equivalent to 42000 km, very Longmont Christian School, 550 N Coffman St near our currently acceptedvalue of 40,000km. Henrietta Leavitt was at Harvard College Observatory in 1892. August20-23 Weekend Under the Her studies of Cepheid variable stars uncovered the fact Foxpark, Wyoming that intrinsically brighter Cepheids have longer Contact Marty Currary 307-635-5944,Cheyenne \AtrY periods. Since the period can be readily determined, Web info at http:/ /users.sisna.com/mcurran even for Cepheids in other galaxies, these stars may be used as standard candles for distance estimates. Harlow is accompaniedby a visible star cluster;the Eagle (M16: Shapley and Edwin Hubble were able to apply this RA 18h18m48s,DEC -13d47m00simag. 9.9,dist. 2.5 kpc), knowledge to determine that the spiral nebulae were location of the famous cloud pillars photographed by the truly distant galaxies. Annie Jump Cannon lived from Hubble; the Omega (M17: RA 18h20m48s,DEC -16d11m; 1,863-1942. She provided the basis for stellar mag. 6.0, dist. 1.5 kpc), which abuts the dust cloud; and classificationby spectral type. By personally evaluating the Trifid (MZ0: nA 18h02mL8s,DEC -23d02m; mag. 6'3, over 5O000 stellar spectra, her work gave the foundation dist. 1,.6kpc), located between M8 and M21, which is one for our now familiar classes: OBAFGKM, ranging from of most well known nebulae. hot to cool stars. Subsequent plotting of vs spectral class, the Hertzsprung-Russell diagram, has The brightest star in the South is Antares (RA 'l.6h29m24s,DEC been the key to our theory of . The H-R -26d25m55s;mag. 1.1v dist. 185pc: 600 diagram also helps date star clusters. JocelynBell was 1y). This large red star has a faint companion. Antares is born in 1943. She failed the higher ed entrance exam at an example of a "semi-regular vatiable", a star whose 11th grade, but persisted and became a graduate student brightness occasionallychanges periodically. at Oxford. In L967 she detected regular, rapid signals from space,dubbed LGM for Little Green Men. Initially There are several interesting globular clusters visible in there was excitement over the possibility of a sentient this area. For instance, near Antares is M4 (RA source for the signal. Soo& similar signals were found in 16h23m36s,DEC -26d32m;mag. 5.8, dist. 2.L kpc), which all directions, at different rates, and it was concluded is famous for having an apparent line of stars. that rapidly spinning neutron stars, the pulsars, were Othersare: M14 (RA 17h37m36s,DEC -03d15m;mag.7.6, responsible. Their density is thousands of tons per dist. 10.2kpc); M19 (RA 17h02m36s,DEC -26d1"6m;mag. teaspoory and they are can be less than a mile in 6.7, dist.10.6 kpc); M22 (RA 18h36m24s,DEC -23d54m; diameter. Bell still teachesat an open university, giving mag. 5.1, dist. 3.1 kpc); M28 (RA 18h24m30s,DEC- other late bloomers an opportunity for higher education 24d52m00s;mag. 6.8,dist. 5.8 kpc); M62 (RA 17h01m12s, as she had. DEC -30d07m00s;mag. 6.7, dist.6.1 kpc); and M80 (RA 16h17m00s,DEC -22d59m00s;mag. 7.3, dist.8.0 kpc). Rocky Mountain National Park Star Parties, Upper Beaver Meadows There are several open clustersvisible. The Wild Duck Dates are: luly 3, July 17, July 31, August 1{, August 28. Cluster (ML1: RA 18h51m06s,DEC -06d16m00s;mag. Let Ken Vanlew know if you would like to take part this >:11.O dist.1j2 kpc) is perhapsthe most famous. summer, 226-2500extension 8724. Nearby in our field of view are the two outermost planets Dates for Discovery Center Star Parties in the Solar System, Neptune and Pluto, and four bright Scopesare needed:Sept 23, Oct21.,Nov 18,Dec 16. asteroids; one of these asteroids, Iris, reachesopposition (opposite in position to the Sun) on the L0th. Longs Peak by Moonlight Ken Van Lew is leading a nighttime walk up Longs Peak Neptune is at magnifitde 7.9, and can be found at RA August 9th. Expect to be on the trail from 2 AM to 3 PM 20h14m03s,DEC-19d30m46s. It is a gas giant 17 times as for this L5 mile roundtrip. Contact Ken at 229-9789. massive and four times as large (in diameter) as Eartt! and presently lies at a distanceof over 29 au from us. ]uly Observers' Guide, by Brad jarvis Locations of Solar System o$ects are for 10:00p.m. MDT Pluto, forming a "double planet" with its moon, Charory on July 1 unless otherwise noted. Seechart below, where is slightly closer to us than Neptune. This planet is just a tick marks are by the week. third larger (in diameter) than our own Moon. Pluto has a magnitud e of 13.7,which may barely be detectableby a On the evening of the 1,4thJupiter and the Moon will be 10" telescope,and is at RA 16h25m18s,DEC-09d08m32s. two degrees apart. We'll be able to see them shortly '1,1,:27, before midnight Jupiter rises at and the 65% In the table of asteroids below, "D" is diameter in km, illuminated Moon rises at 11:51. "R" is average radius of the orbit in att, "P" is the orbital period in years (how long it takes to go around the SunL This month we'll concentrate on the region of the sky 'li4AG'is magnitude,"RA" is the RA at 10 p.m. onJuly 1, around the Sagittarius and Scorpius. Here with "DEC" the declinatioo and "SPEED" is the starting we're looking toward the center of the Galax!,but due to apparent speed in arcsecper hour. obstructing dust which shrouds an intervening stellar nursery in this part of the Galaxy's Sagittarius Arm, PMG,M DEC SPEED which lies adjacent to our own Orion Arm, we can't see Ariodne 65 3.1 3.3 9.7 20h16n33s -16d28m50s27 very far (radio and infrared telescopescan "see" much Iris 2O33.3 3.7 8.9 19h26n56s -17d47n25s 37 more). Newborn stars light up gas in parts of this Melpomene? 3.2 3.5 9.8 lTht&nZ8s -O7d38n@8s35 nursert appearing as nebulae. Such nebulae include: the Hebe 192 3.4 3.8 9.6 16h3uln16s-@2dlh@Zs 30 Lagoon (M8: RA 18h03m,DEC -24d23mi mag. 5.0),which BestLooks Time MDT Az E1 Mir Moon Near Venus 7/21 \M/DD/\Y HH:MM:SS Deg Deg Vi si bit ity Mercury With Moon inW 6125 07/15/98 3:01:56 AM 335.0 23.4 Out of Shodow Venus Near Iota Tauri 7 I 8 07/!5/98 3:06:33 AM 45.9 t.0 ll LuminotedSet Jupiter In $ mornings Saturn Low in SE,morning 07/t7/98 7:32:23 AM 348.1 18.6 Out of Shodow Uranut Neptune In S predawn 07/L7/98 2:36:32 AM 45.2 0.9 Itluminoted Set Pluto Magnitude 137 inS, eves 07/2I/98 4:40:3L AM 312.7 0.2 Illuminoted Rise Mir in July. Times are estimates as of late june. Best O7/?l/98 4:45:?5 AM ?7.4 26.0 Illuminoted Mox @ 07/21/98 4:50:01 AM 98.6 0.9 Iltuminoted Set

Times are MDT, Fort Collins/Loveland. Az is compass 07/23/98 4: 10: 11 AM 31-1. 5 0 .7- Itluminoted Rise Mox direction, N:0, E:90, 5:180, W:270. Elevation above 07/23/98 4:l-5:06 AM 26.? 34.3 Illuminoted 07/23/98 4:2Q:QOAM Iq7 .0 0.5 Illuminqted Set horizorL 10 degrees,about a hand-width at arm's length. 07/23/98 10:17:33 PM ?33.9 L.t Illuminoted Rise Time MDT Az El Mir A7/23/98 tO:.22:28 Pl{ 4.0 80.4 Illuminoted Mox |M/DD/YYHH:tdt4:SS Deg Deg Vi si.bi t ity 07/?3/98 IO:27:22 Pl"l 53.1 O.5 In shqdowSet 07/06/98 4:25:58 AM t8O.2 tt.z Out of Shodow 07/24/98 4:42:57 AM 3O4.L 0.7 Illuminoted Rise 07/06/98 4:28:03 AM 134.6 ZO.L Illuminoted Mox 07/24/98 4:47:5t AM 224.4 64.3 Illuninoted Max 07/06/98 4:32:39 AM 66.6 O.6 Illuminoted Set 07/?4/98 4:52:46 AM L34.7 O.7 Illuminoted Set O7/O7/98 4:58:00 AM 23O.7. 10.8 Out of Shodow 07/24/98 9:14:37 PM 213.3 0.7 Illuminoted Rise 07/O7/98 5:OA;56 AM t6!.3 84.Q llluminoted I'|g'x 07/24/98 9:L9:32 PM 129.7 35.3 Illuminoted Mox 07/A7/98 5:05:51 AM 54.1 L.O Doylight Set 07/?4/98 9:?4:QBPM 60.7 t.O Illuminoted Set 07/08/98 3:57:32 AM t67.9 25.9 Out of Shodow 07/24/98 10:50:28 PM 260.9 0.7 Ittuminoted Rise @7/CI8/983:58:20 AM L37.7 30.6 llluminoted Max 07/24/98 10:55:05 PM 330.3 26.3 Illuminoted Mox 07/08/98 4:03:1-5AM 61-.6 0.3 Illuminoted Set 07/24/98 10:59:59 PM 47.L Q.4 Illuminqted Set O7/O9/98 4:29:16 AM 247.3 Lg.O Out of Shodow A7/?5/98 3:39:45 AM 3O9.7 0.L Illuminoted Rise O7/09/98 4:3I:L4 AM 316.3 62.2 llluminated |hx 07/25/98 3:44:58 AM 43.1 48.0 Illuminoted Mox 07/09/98 4:36:08 AM 57.2 1.1 Illuminoted Set 07/25/98 3:49:52 AM L15.4 q.0 Illuminoted Set 07/LO/98 3:28:59 AM 111.3 44.8 Out of Shodow 07/25/98 9:47:O7 Pl{ 242.5 A.9 Illuminoted Rise 07/L0/98 3:33:39 AM 57.7 0.L Ittuminoted Set 07/25/98 9:52:OL Plt 332.4 54.4 Illuninoted Max 07/25/98 9:56:55 PM 50.7 0.6 Illuminoted Set 07/tO/98 5:00:53 AM 27L.6 4.6 Out of Shodow @7/IO/98 5:O4:36 AM 338.6 ZZ.4 Illuminoted Mox 07/26/98 4:!7:54 AM 195.8 37.0 Out of Shodow 07/tO/98 5:09:12 AM 46.2 0.6 Doylight Set @7/26/98 4:?2:18 AM I43.7 0.3 Illuminoted Set 07/LL/98 4:00:L9 AM 274.4 26.4 Out of Shodow 07/26/98 L@:2Q:1QPM ?68.2 0.s Illuminoted Rise A7/17/98 4:.Ol:32 AM 326-0 41.9 Illuminoted Mqx 07/?6/98 LQ:?4:,46PM 336.0 ?A.9 Illuminoted Mox 07/rL/98 4:A6:27 AM 49.1 O.8 Illuminoted Set 07/26/98 1@:29:22PM 4s.6 0.9 Iltuminoted Set 07/12/98 Z:59:58 AM 60.4 33.6 Out of Shodow 07/27/98 9:16:45 PM 250.9 1.l" Itluminoted Rise a7/t2/98 3:03:39 AM 54.6 L.O Illuminoted Set 07/27/98 9:27:2L PM 322.8 37.7 Illuminqted l,4ox 07/?7/98 9:25:16 PM 48.4 L.0 Illuminoted Set a7/12/98 4:31:55 AM 285.1 6.9 Out of Shodow 07/L2/98 4:34:54 AM 34L.3 L8.? Illuminoted Mox 07/28/98 9:49:51 PM ?75.3 0.5 Iltuminoted Rise 07/L2/98 4:39:30 AM 46.3 0.2 Illuminoted Set A7/28/98 9:54:27 PM 342.5 \7.3 Illuminoted Max 07/?8/98 9:59:03 PM 46.5 Q.O Illuminoted Set 07/L3/98 3:31:18 AM 3LZ.L 28.6 Out of Shodow 07/13/98 3:31:48 AM 332.O 3Q.4 Illuminoted l'4qx 07/29/98 8:46:I2PM 258.6 0.7 Doylight Rise 07/L3/98 3:36:42 AM 47.8 0.3 Illuminoted Set 07/29/98 8:50:48 PM 327.3 28.1 Illuminoted Max @7/29/98 8:55:43 PM 47.L 0.7 Iltuminoted Set 07/L4/98 2:30:36 AM 43.8 23.2 Out of Shodow 07/14/98 Z:33:48 AM 51.8 O.8 Illuminated Set

a7/L4/98 4:02:32 AM 296.t 7.5 Out of Shodow 07/74/98 4:Q5:O3AM 342.1 15.3 Iltuminoted Mox @7/14/98 4:Q9:39 AM 46.6 Q.L Illuminqted Set Map for |uly 1 at 10:00PMMDT A Few lridium Satellite Flares. IMPORTANT! The intensity of these flares is very sensitiveto your position, so pleasetry to know your coordinatesas accuratelyas possible. A position error of 1Okm on the ground can change the flare intensity by severalvisual magnitudesl Accurate time is also critical. Observer'sLocation: Near Lemay and Trilby in Fort CollinsCO ( 40.50'N, 105.05'W). LocalTime: MountainDaylight Time (GMT- 6:00) CurrentMir and lridiumpredictions are availableon the Web at: http://www2. gsoc.dlr.delscripts/satvis/satvis.asp? Lat=40.50&Ln9=-105.0500&Loc=Fort+collins&TZ=MDT Site now gives directionsfor maximumlridium flare magnitude. From: Date Time Magnitude Elev. Azimuth 30 Jun 23:L3:AO -5 27 246 (SVi) c/o Dan Laszlo 01 Jul @4:Q2:O3 -3 3? lLZ (E ) 2001S ShieldsSt Building H 01 Jul 23:07:Q0 -5 2.8 247 (SW) Fort Collins CO 80526 0? Jul 03:55:54 -5 31 113 (SE) 03 Jul 23:03:57 -2 24 2s2 (Ur) TO: 04 Jut 22:58:@? -5 24" 2s3 (Ul)