Clarissa Asteroid Occultation over DC & Maryland Sept. 27/28; Other Mid-Atlantic Occultations to early November 2002
Updated: 2002 September 26The Clarissa occultation of a 9th-mag. star across northern Maryland on Friday night, Sept. 27/28, provides us an opportunity to observe an asteroidal occultation even from light-polluted skies - I hope that more observers than usual will try this good event, maybe YOU can time your first asteroidal occultation (or 2nd or 3rd . .). There are some even better events later this fall, but it looks like we'll need to travel a little (or a lot) to see them; at least the two really good asteroidal events in November are on weekends so I hope again you can mark your calendars and join our expeditions for them. Things are quite uncertain about Friday night's occultation, as you can see below. Lots of clouds are moving in from the hurricane; the big question is how fast will they move through and when it will clear up afterwards. The current forecasts are calling for that to happen well after the occultation, but often the clearing afterwards occurs faster than planned. There is a good chance that it won't clear up here, but will in West Virginia, in which case I will drive there to observe it, leaving possibly in the early afternoon Friday, making a preliminary decision this (Thurs.) evening and a final one Friday morning. To find out what I'm doing, call me at home at 301-474-4722 or, if nobody answers, 240-228-5609, where you can leave a message that I can retreive remotely. Also, I will put my plans on the IOTA occultation answering machine at 301-474-4945, and if I'm not home or in my office, you can reach my cell phone at 301-526-5590. If it looks like a reasonable chance, I will compute a station list for the Clarissa event, but won't with the current forecast. Update message from Sept. 23: Recent accurate astrometric observations have been used to update the path form Friday night's path for the occultation of 9.3-mag. PPM 144222 by (302) Clarissa, showing that the path is about a path-width north of the earlier prediction. The expected path now passes over northern Maryland and Philadelphia, with the southern limit approximately over Ellicott City, northern Baltimore, and Wilmington, DE; and the northern limit near Hagerstown, MD and crossing I-83 just north of the Mason-Dixon line. But the uncertainty in the prediction is large enough that it could still cross the Washington, DC area, so observers there are encouraged to watch, even if they are not mobile. Mobile observers are encouraged to join an organized effort to observe the graze from northern Maryland, if weather permits. But that could be a big "if". The long-range Accuweather forecast is poor for the whole path from southern Oklahoma to Nantucket. Hopefully, they will be wrong, but if not, I may try to travel west to try to catch the event. The updated path is shown at Steve Preston's site which shows that the event will occur during the second half of 4:45 UT (12:45 am EDT) Sat. morning, Sept. 28, in northern Maryland. The star is at J2000 RA 1h 03m 51.8s, Dec +7 deg. 14' 49" in Pisces; a finder chart can be found in the table of the IOTA asteroidal occultation page. ___________________________________________________________ Mid-Atlantic Occultations and Expeditions to early Nov. 2002 First, predictions for asteroidal occultations are given; then, planned expeditions for lunar grazing occultations; and third, predictions of total lunar occultations visible throughout the region. This is a limited update, mainly for the asteroidal occultations, of my May message (and some added notes for the grazes in Aug.); a more thorough update will be distributed in a few days, to make the list complete to early October. _________________________________________________________________________ Asteroidal Occultations through early Nov., 2002 and some later EDT/ dur. Ap. Date Day EST Star Mag Asteroid dmag s in. Location Sep 28 Sat 0:45 PPM 144222 9.3 Clarissa 4.3 4 3 WV,nMD,sePA Oct 15 Tue 1:30 SAO 076241 9.3 Athor 3.6 7 3 Georgia, Texas Oct 15 Tue 19:41 TYC68811521 11.3 Beatrix 2.5 4 8 Mich., Ontario Oct 16 Wed 0:30 zeta Arietis 4.9 Wangshouguan 10.1 5 .2 n. New York *** Dates and times above are EDT, those below are EST *** Oct 27 Sun 3:29 SAO 97305 8.9 Alagasta 6.4 5 2 central VA Oct 28 Mon 0:53 TYC11580420 11.4 Dysona 3.2 20 8 s. Florida Oct 28 Mon 2:36 TYC33750991 11.7 Patricia 3.4 7 8 Atlantic,Labr. Oct 29 Tue 20:35 TYC28491172 11.4 Urhixidur 2.0 6 8 s. Florida Nov 2 Sat 20:48 ZC 0593 5.9 Nephele 7.3 9 1 WV,w.MD,e.PA Nov 10 Sun 2:32 pi Arietis 5.2 Lindemannia 9.5 4 .3 s. GA, s. SC Dec 24 Tue 4:56 SAO 097327 8.5 Chicago 5.1 13 3 n. MD, s. NJ Notes: Only the events on Sep. 28, Oct. 27, Nov. 2, and Nov. 10 have good astrometric updates, but in some cases the last observations were made a year ago and we are waiting for recent data to refine the prediction. In general, only for stars of 9th mag. and brighter will we consider an expedition outside of the Mid-Atlantic states region. Especially for the fainter stars and events of shorter duration, we will plan no observations unless an astrometric update indicates a reasonable chance for an occultation in the Mid-Atlantic states. _________________________________________________________________________ Grazing Occultations through early Nov. 2002, and some later EDT\ DATE Day EST Star Mag % alt CA Location Sep 9 Mon 20:18 SAO 139534 8.9 12+ 10 7N timed, Herndon,VA &s.Bowie,MD Sep 27 Fri 23:51 ZC 761 6.7 65- 16 13N * Hampton & Suffolk, VA Sep 28 Sat 5:25 SAO 077053 8.8 63- 74 12N Clinton,UpMarlboro,KentIs.,MD Oct 3 Thu 5:08 eta Leonis 3.5 13- 25 8N Indian River, MI Oct 9 Wed 20:12 ZC 2327 6.7 17+ 8 1N * Pittsburgh, PA area Oct 17 Thu 0:04 tau1 Aqr 5.7 84+ 30 7N * Pittsburgh, PA area *** Dates and times above are EDT; those below are EST *** Oct 27 Sun 3:52 ZC 1046 7.0 70- 73 6N Westminster, MD & Newark, DE Oct 27 Sun 5:44 SAO 078824 7.9 69- 76 1N Beltsville & n. Bowie, MD Nov 10 Sun 18:16 ZC 3032 7.5 40+ 25 7S * Somerset & Winber, PA Nov 14 Thu 21:26 30 Piscium 4.4 79+ 44 12S DC; Beltsville, MD; ZC 3536 Nov 23 Sat 8:07 epsilonGem 3.1 89- 23 8S Wilson, NC; Sun +11; ZC 1030 Dec 10 Tue 19:09 ZC 3374 6.1 43+ 34 14S Harmony, PA Dec 13 Fri 20:08 35 Ceti 6.5 71+ 52 14S n. Hancock, MD; ZC 178 Notes: I don't expect to try the grazes late this month, concentrating more on the Clarissa asteroidal occultation and preparations for 2003 predictions. But if want to try them, let me know and I can supply predictions. I may try one if the sky is very clear and other things don't interfere too much. Sep. 27, ZC 761: This is only about an hour before the Clarissa asteroid occultation in the DC area, so Clarissa will have priority. * means no expedition is planned from the DC area, but I can provide more information if local observers want to attempt them, including contacts for others in the area who might also be interested. _________________________________________________________________________ Total Lunar Occultations The better total lunar occultations through early Nov. 2002 visible from throughout the Washington-Baltimore greater metropolitan area are listed below. Many can be accurately timed by aiming a camcorder into a low-power eyepiece of your telescope and recording WWV with the audio. EDT/ DATE Day EST Ph Star Mag % alt CA Sp. Notes Sep 28 Sat 2:55 R SAO 077019 7.9 64- 50 36S F5 Sep 28 Sat 3:04 R SAO 077015 9.0 64- 51 73S A0 Sep 29 Sun 5:51 R SAO 078069 8.4 53- 72 45S B9 db.,8.4&10,sp5.7",PA356 Sep 29 Sun 6:21 R SAO 078081 8.3 53- 75 72S G5 Sun alt. -9 deg. Sep 30 Mon 2:02 R SAO 079014 7.9 43- 32 88N G8 Sep 30 Mon 4:01 R SAO 079054 6.9 43- 42 16S K8 db.,7.3&10,sep14",PA50d Sep 30 Mon 4:34 R SAO 079098 8.4 42- 60 45S K5 db.,8.4&8.4,sp25",PA103 Sep 30 Mon 6:07 R SAO 079114 8.5 42- 66 75N A3 Sun alt. -11 deg. Oct 1 Tue 2:16 R ZC 1208 6.3 33- 12 12S K1 db.,6.4&11,sp2.1",PA324 Oct 1 Tue 2:16 R SAO 079854 9.1 33- 12 73S F8 R 26 sec. after ZC 1208 Oct 1 Tue 2:43 R SAO 079868 7.3 33- 17 83N K0 db.,7.3&13,sp1.4",PA164 Oct 1 Tue 4:03 R SAO 079917 8.4 32- 32 27S G5 Oct 1 Tue 5:28 R SAO 079961 8.1 32- 48 44N K0 Oct 1 Tue 5:56 R SAO 079966 8.7 32- 53 58S F5 db.,9.5&9.5,sp.1",PA72d Oct 2 Wed 4:18 R TZ Cancri 9.1 22- 56 53S M0 Close triple; SAO 80608 Oct 2 Wed 5:09 R SAO 80626 8.5 22- 32 90N K0 Oct 3 Thu 4:40 D eta Leonis 3.5 13- 25 -46N A0 cl.dbl.; graze in Mich. Oct 3 Thu 6:33 R ZC 1484 3.5 13- 35 64N A0 eta Leo; Sun alt. -7dg. Oct 9 Wed 20:03 D ZC 2327 6.7 17+ 8 22N G3 Oct 14 Mon 22:58 D SAO 190052 7.9 68+ 22 47N F8 Oct 15 Tue 23:31 D SAO 164795 8.1 77+ 26 48N M2 Oct 16 Wed 1:00 D ZC 3227 6.3 77+ 15 70S K0 Oct 17 Thu 1:17 D tau2 Aqr 4.1 85+ 23 58S K5 ZC 3349; Dec.2001 graze Oct 18 Fri 18:56 D ZC 0018 5.8 95+ 13 9S K1 Sun -7; 3" to terminator Oct 21 Mon 22:30 R xi Arietis 5.5 99- 41 7S B7 at terminator; difficult Oct 25 Fri 23:56 R TU Tauri 8? 79- 30 74S M5 SAO 77502; var. 5.9-9.2 Oct 26 Sat 1:24 R ZC 0880 6.8 79- 47 88N K2 Oct 26 Sat 1:53 R 132 Tauri 4.9 79- 52 50S G8 ZC 882; maybe close dbl. Oct 26 Sat 23:57 R SAO 078629 7.6 70- 21 75N M Oct 27 Sun 0:21 R SAO 078653 7.4 70- 25 44N M0 Oct 27 Sun 0:22 D epsilonGem 3.1 70- 25 -59S A3 ZC 1030 Oct 27 Sun 1:09 R epsilonGem 3.1 70- 34 33S A3 ZC 1030; camcorder? *** Dates and times above are EDT; those below are EST *** Oct 27 Sun 3:45 R SAO 078778 6.8 69- 73 80S K0 probable close double Oct 27 Sun 4:03 R ZC 1046 7.0 69- 73 21N F8 graze, Westminster, MD Oct 27 Sun 5:04 R ZC 1049 6.8 69- 75 57N A2 Oct 27 Sun 5:07 R SAO 078824 7.9 69- 75 7N F0 graze, Beltsville, MD Oct 27 Sun 5:45 R SAO 078827 7.4 68- 70 43S A Sun alt. -9 deg. Oct 28 Mon 4:52 R ZC 1180 7.1 59- 73 53S F5 Oct 29 Tue 4:32 R SAO 080414 8.2 48- 61 85S A2 Oct 30 Wed 4:43 R ZC 1435 6.5 37- 51 38N K0 Oct 30 Wed 5:44 R ZC 1436 6.8 36- 61 54N K0 Sun alt. -10 deg. Oct 31 Thu 3:19 R SAO 099207 8.2 27- 23 74S F8 Oct 31 Thu 4:09 R SAO 099223 8.3 26- 32 85S F5 Oct 31 Thu 4:12 R SAO 099225 8.1 26- 33 75N K0 Nov 3 Sun 5:01 R 65 Vir 5.9 3- 1 70S K3 ZC 1921, Azimuth 97 deg. Nov 3 Sun 5:36 R 66 Vir 5.8 3- 7 55S F3 ZC 1924, Azimuth 103 deg. D following the time denotes a disappearance, while R indicates that the event is a reappearance. When a power (x; actually, zoom factor) is given in the Notes, the event can probably be recorded directly with a camcorder of that power with no telescope needed. The times are for Greenbelt, MD, and will be good to within +/-1 min. for other locations in the Washington- Baltimore metropolitan areas unless the cusp angle (CA) is less than 30 deg., in which case, it might be as much as 5 minutes different for other locations across the region. Mag is the star's magnitude. % is the percent of the Moon's visible disk that is sunlit, followed by a + indicating that the Moon is waxing and - showing that it is waning. So 0 is new moon, 50+ is first quarter, 100+ or - is full moon, and 50- is last quarter. The Moon is crescent if % is less than 50 and is gibbous if it is more than 50. Cusp Angle is described more fully at http://www.lunar-occultations.com/iota. Sp. is spectral type-color, O,B,blue; A,F,white; G,yellow; K,orange; M,N,S,C red _________________________________________________________________________ Phone the IOTA occultation line, 301-474-4945, for weather go/cancel decisions, and other updates and details, or check IOTA's Web site at http://www.lunar-occultations.com/iota which now has an asteroidal occultation section with finder charts and updated path maps. Timing equipment and even telescopes can be loaned for most expeditions that we actually undertake; we are always shortest of observers who can fit these events in their schedule, so we hope that you might be able to. The IOTA occultation line at 301-474-4945 is back in operation, but you'll often get the latest information instead by e-mail. Good luck with your observations. David Dunham, e-mail dunham@erols.com, 2002 September 26 Phone home 301-474-4722; office 240-228-5609; car 301-526-5590.