Observing report for Ealing II training 5/4/2005 2:30-4:30 UTC 5/3/2005 8:30 PM-10:45 PM MDT Mark Bloomenthal (instructor) Allen Rowe (student) Kurt Fisher (student) This training was fit into an "East Coast"-style observing session - a brief hole of clear air between two storm fronts. This session began in civil twilight at 8:32pm MDT. The first visible celestial object, Jupiter (-2.0m), was used as the initial target at approximately 2:40 UTC. The RASC Observer's Handbook lists the following events for Jovian satellites from 0:00-4:00 UTC for Io (period 3.55 days, orbital distance 670,900km): 00:47 UTC Io transit ingress 01:28 UTC Io shadow ingress 02:58 UTC Io transit egress 03:39 UTC Io shadow egress On bringing Jupiter and focus, Mark saw that Io was in mid transit egress (the 2:58 UTC event in the Handbook) and that there was a satellite shadow on the surface of Jupiter (the 1:28 UTC event in the Handbook). The upper half of the following figure illustrates the view in the eyepiece at approx. 2:40 UTC. Io is in mid-transit egress at the 315° position angle and Io's shadow falls on the planet's surface: http://members.csolutions.net/fisherka/astronote/observed/20050504JupiterObs... (Sketch generated with Paul Stoddard's online Jovian system simulator at << http://jove.geol.niu.edu/faculty/stoddard/JAVA/medici.html
.)
Magnification applied was 127x (Meade Ultra-wide 40mm supplied by Allen) and 257x (a low-end 20mm supplied by Kurt). Cloud band detail and the Great Red Spot were visible during brief periods of atmospheric calmness. Various combinations of aperture mask and a yellow No. 12 filter were tried to improve contrast and detail. Aperature masking improved detail, however Jupiter was at 25°-35° in altitude. Seeing was atmospheric limited with Jupiter switching back and forth from a blur to fine detail over a minute of viewing. Jupiter recently moved past opposition (April 16). The following sketch illustrates the relative Sun, Earth and Io angle as seen from Jupiter at the 00:47 UTC Io transit ingress listed in the Handbook: http://members.csolutions.net/fisherka/astronote/observed/20050504JupiterObs... (Illustration generated with JPL solar system simulator << http://space.jpl.nasa.gov/ >>.) Io transited between the Earth and Sun (moving right to left in the above Jupiter view illustration), ending at 3:39 UTC at the position seen in the lower half of the first figure - http://members.csolutions.net/fisherka/astronote/observed/20050504JupiterObs... The sky progressed from civil to astronomical twilight. Since the aperture mask was still in place, Saturn (-0.3m) was chosen as the next target. At 257 x-ray, some fine band detail could be seen in the planet's desk. At 3:30 UTC, we returned to Jupiter in order to view the last listed event in the Observer's Handbook, Io's shadow egress. Due to either timing or poor seen, the shadow egress was not seen. The group's time spent with Jupiter was a good preview to the 14 Jovian double shadow transit events listed in the Observer's Handbook for May and June, 2005. The SLAS club astrophotography challenge for May is photographing one of these double shadow transit events. But (if I have read the tables in the Observer's Handbook correctly), only three of these events will occur between local sunset and sunrise: DateUTC UTC DateLocal LocalTime LocalSunrise_or_set May 16 Mon 10:48 May 16 04:48 AM 5:38 AM MDT rise Jun 10 Fri 05:29 Jun 9 11:30 PM 8:59 PM MDT set Jun 17 Fri 07:57 Jun 17 01:57 AM 9:00 PM MDT set By 3:45 UTC, astronomical twilight had begun. The Virgoan Realm of the Galaxies was still in the eastern light pollution zone that intrudes into the SPOC site, so we passed on entering the Realm. Since this was a meridian swap training session, a series of basic targets emphasizing RA movement around a local sidereal time of approx. 11:00:00 for 3:00-4:00 UTC were selected: 1) a wide-double (17") at the edge of the zenithal good-seeing zone - HD79210 (STF1321), 1° degree west in RA from theta UMa. This was a nice pair of equal garnet-colored class M stars (J091423+52412, 7.8-7.9m, M0V-M0V). 2) the classic close double, alp CVn (J125602+381906, 2.9-5.6m, A0-F0V), or Cor Caroli ("The Heart of Charles") as named by Edmund Halley in honor of Charles II of England. 3) the classic globular cluster M3 (J134230+282300). 4) the Leo Triplet - M65 (NGC 3623), M66 (NGC 3627) and edge-on spiral NGC 3628 (J112020+125900). These are the bright components of the M66 galaxy subgroup of the Leo I galaxy group, lying about 35 million light-years distant. On May 5, Tyler Allred posted an excellent picture of this triplet on this mail list at << http://www.utahastronomy.com/album16/Utah_Astronomy_M65
Our observing of the Leo I galaxy group was interrupted by a single, narrow, thick, rapidly-moving band of low-altitude clouds. This band of clouds announced the end of our "East Coast"-style observing session. The western horizon was full of clouds on the leading edge of the next storm front. No increase in the background rate of meteors was seen. The eta Aqu meteor shower peaked the following night. As this was a training session, the usual measurements of ZLM and target NELM were not made. Many thanks to Mark for his repeated rescheduling (3x) of this Ealing II training session in the face of an uncooperative weather pattern. - Canopus56 (Kurt) __________________________________ Yahoo! Mail Mobile Take Yahoo! Mail with you! Check email on your mobile phone. http://mobile.yahoo.com/learn/mail