****************************************************** Abrams Planetarium SKYWATCHER'S DIARY: October 1997 ****************************************************** The Skywatcher's Diary for October 1997 has been prepared by Robert C. Victor. Credit to Abrams Planetarium, Department of Physics and Astronomy at Michigan State University, together with mention of our Sky Calendar, would be appreciated. A sample recent issue of Sky Calendar is available over the Internet. It can be viewed via a World-Wide Web browser such as Netscape or Internet Explorer, directly at URL: http://www.pa.msu.edu/abrams/apr97skycal.html If you would like a printed sample of the October issue, send a long, self-addressed stamped envelope to: October Sky Calendar Abrams Planetarium Michigan State University East Lansing, MI 48824 Each month, the Department of Physics and Astronomy at Michigan State University also makes Skywatcher's Diary available over the Internet. It can be accessed via a World-Wide Web browser such as Netscape or Internet Explorer, directly at URL: http://www.pa.msu.edu/abrams/diary.html The Skywatcher's Diary is also available via anonymous ftp at: www.pa.msu.edu in the directory /pub/swd ****************************************************** October Highlights: Four planets at dusk, Moon gatherings, and Zodiacal Light Venus gleams low in SW at dusk. It appears as the brightest "star" in the sky until it sets soon after nightfall. For most of this month, two fainter red objects, Mars and Antares, appear close by. Mars on October 1 is 9 degrees upper left of Venus and 8 degrees right of Antares. Watch arrangement of Venus, Mars, and Antares shrink nightly until midmonth, as both planets approach the star from the right. On Oct. 12, Mars passes 3.4 degrees upper right of Antares, with Venus 5 degrees to their right. Four nights later, on Oct. 16, Venus passes only 1.7 degrees upper right of Antares. Throughout the week of Oct. 12-18, Venus Mars, and Antares form a compact group easily fitting within the field of view of 7-power binoculars. Thereafter, Venus and Mars stay within 3 degrees apart October 19-31, with Venus passing just over 2 degrees lower left of Mars on Oct. 24-26. Meanwhile, Antares sinks into bright twilight, to the planets' lower right. Bright Jupiter is in SSE at dusk, and climbs to its highest in south an hour after nightfall early in month, or around nightfall near month's end. Once Venus has set, Jupiter is brightest "star" in sky until it also sets, some 5 hours after passing due south. Saturn is low in E at dusk, and reaches its high point in south four hours after Jupiter does, but 22 degrees higher. Saturn's rings are now 10 degrees from edge-on. Six hours after passing due south, Saturn is very low in W. As the Moon waxes from crescent to Full Oct. 3-15, it guides skywatchers to three bright planets and a bright star at dusk: On Oct. 5 and 6 a thin crescent Moon passes above Venus, Mars, and Antares. A gibbous Moon, just past First Quarter and just over half full, passes Jupiter on Oct. 10 and 11. Saturn is near the Moon on the nights of Oct 14 and 15. The Moon is Full on Oct. 15. On the night of Oct. 18-19, Aldebaran rises close on the heels of the waning gibbous Moon, then is covered by the Moon later that night from all of U.S. except Alaska; see entries for Oct. 17 and 18 in Skywatcher's Diary. The Moon is still near Aldebaran at dawn on Oct. 19, and, as a crescent, is near Regulus at dawn on Oct. 25. If your skies are very clear and dark, far from the lights of "civilization", Sept. 30-Oct. 14 and Oct. 30-Nov. 12 are excellent mornings to try to observe the zodiacal light. It appears as a huge softly luminous cone of light sloping upward from the eastern horizon, seeming to engulf or point toward Regulus, and is caused by dust in the plane of the solar system, the dust being originally from comets and asteroids. To detect the zodiacal light about 1-1/2 hours before sunrise, compare that section of the sky to the darker areas to its left and right. *********SKYWATCHER'S DIARY OCTOBER 1997********* Wednesday, October 1 The Moon is New today at 12:51 p.m. EDT, the first of two New Moons this month. The entire cycle of lunar phases fits within this calendar month. Try this activity: Oct. 3-15 daily at dusk, about 45 minutes to an hour after sunset, look for the Moon and make a drawing of what you see, including its phase (shape and orientation of its lighted area), direction in the sky, and any bright objects you find nearby. Repeat daily at dawn Oct. 16-29. Look for these objects tonight, one hour after sunset: Venus, brilliant, very low in SW; faint Mars 9 degrees upper left of Venus, and Antares 8 degrees left of Mars. Jupiter, bright in SSE; and Saturn, very low in E, 65 degrees lower left of Jupiter. Use these objects to help you plot the Moon's position for the next two weeks. Thursday, October 2 About 20 minutes after sunset tonight, if the sky is very clear, use binoculars to search for the Moon very low, about midway between W and WSW. Tonight the Moon is about 30 degrees lower right of Venus. The Moon's age in Michigan is then 31 hours after New, but it's far from Earth and has moved only 14 degrees to Sun's upper left. From southern U.S. and the Southwest, Moon is higher and sets later in a darker sky, and is easier to see. As the sky darkens after moonset, look for Mars 9 degrees to Venus' upper left, and then the 2nd magnitude star Delta in Scorpius within 1 degree below Mars. Friday, October 3 Forty-five minutes after sunset, the thin young crescent Moon is very low in WSW and is quite easy to see if you view is unobstructed. Venus is in the SW 20 degrees to Moon's upper left. Mars is 8-1/2 degrees upper left of Venus, and Antares is 7 degrees left of Mars. Watch the Moon pass these three bodies in the next three nights. 8:00 p.m. tonight, Gateway to Infinity begins a 4-weekend run at Abrams Planetarium. Shows are Fridays and Saturdays at 8:00 p.m. and Sundays at 4:00 p.m., through Oct. 26. Back in April 1993, this was our opening public program at Abrams Planetarium after the new Digistar projector was installed, and it was a big hit! Narrated by James Earl Jones. Our show for adults and children of all ages is WSKY...Radio Station of the Stars, presented Sundays at 2:30 p.m. through December 21. Saturday, October 4 An hour after sunset, the 4-day-old crescent Moon is low in WSW. Venus is 10 degrees to its left, Mars 8 degrees to Venus' upper left, and Antares 6-1/2 degrees left of Mars. Sunday, October 5 An hour after sunset, depending on your location, two planets may form a nearly equilateral triangle with the Moon. Brilliant Venus is 7 degrees below the Moon, and faint Mars is 7 degrees to Moon's lower left. Venus and Mars are themselves within 8 degrees apart. Antares is within 6 degrees lower left of Mars. Just before first light Monday from southern U.S. (Florida and southern half of Georgia to southern California and Hawaii), Comet Hale-Bopp (mag. 5.2?) is 1.2 degrees lower left of 2nd-mag. Zeta Puppis. See Skywatcher's Diary for Sept. 29 for tips on locating this star. Monday, October 6 An hour after sunset, Mars and Antares, "Rival of Mars," are low in SW, 9 or 10 degrees below Moon. Mars is 5 degrees upper right of Antares and 7 degrees upper left of Venus. Tuesday, October 7 An hour after sunset, Moon is one-third full, in SSW. Low in SW, far to Moon's lower right, Venus, Mars, and Antares form a triangle becoming more compact nightly. Each clear evening, make a drawing of the arrangement of the three "stars." Wednesday, October 8 Moon, nearing First Quarter phase and appearing slightly less than half full, is due south around sunset. For a few days around half full, telescopes and even binoculars give spectacular views of craters and other details of the lunar surface. See Touring the Moon with Binoculars at http://www.skypub.com/whatsup/moontour.html Thursday, October 9 Moon, just past First Quarter and just over half full, is in south an hour after sunset. Jupiter is 20 degrees east (left) of Moon. Binoculars show a 2nd-mag star Delta Scorpii less than a degree from Venus tonight and Thursday, while Mars is 6 degrees to Venus' upper left. Find Saturn low in E at dusk, high in S in middle of night, and low in W at dawn. When you look at Saturn tonight, you are facing outward in our solar system, directly opposite to the Sun. Saturn is thus at opposition tonight and is up all night Friday, October 10 An hour after sunset Jupiter is in SSE, about 6 degrees to Moon's lower left. Moon is in gibbous phase, two-thirds full tonight. MSU Observatory open tonight and Saturday, 9:00-11:00 p.m., if skies are clear. Telescopic views will feature Moon, Jupiter, and Saturn. Saturday, October 11 An hour after sunset, find Jupiter about 9 degrees to lower right of waxing gibbous Moon. Sunday, October 12 Very low in SW at dusk tonight, Mars passes within 3-1/2 degrees N (upper right) of Antares. Not until September 1999 will this pair of red objects again appear so close together. Both are 5 degrees from brilliant Venus. A beautiful sight for unaided eye and binoculars! Look nightly all this week and early next. Monday, October 13 An hour after sunset, Moon is in ESE, about three-fifths of the way from Jupiter in SSE toward Saturn in E. Tonight Saturn is about 26 degrees to Moon's lower left. Look nightly. Tuesday, October 14 Moon rises due east about 3/4 hour before sunset (from latitude of lower Michigan). An hour after sunset, look for Saturn about 10 degrees to Moon's lower left. By 1-1/2 hours before sunup on Wednesday, Moon is low in W with Saturn about 5 degrees to upper left. Wednesday, October 15 Tonight the Full "Hunter's Moon" rises 7 degrees N of E within a few minutes of sunset. As the sky darkens, look for Saturn some 4 degrees to Moon's upper right. Low in west 1-1/2 hours before sunup on Thursday, Saturn is about 10 degrees to Moon's lower right. Thursday, October 16 Very low in SW at dusk, Venus passes 1.7 degrees N (upper right) of the red star Antares. Not until October 16, 2005 will Venus again appear so close to Antares! Mars this evening is within 4 degrees to Venus' upper left. From lower Michigan tonight, Moon rises 13 degrees N of E, within 3/4 hour after sunset. Friday, October 17 From northern U.S. tonight, Moon rises 18 degrees N of E, within 1- 1/2 hours after sunset. Note Saturn 35 degrees to Moon's upper right. Look again 3 hours after sunset and find first-magnitude Aldebaran, eye of Taurus, 18 degrees to Moon's lower left. By an hour before sunrise on Saturday, Moon and star will be high in WSW, with Aldebaran 14 degrees to Moon's upper left. The fat waning gibbous Moon will actually occult, or cover, this star on the night of Oct. 18-19. The Moon will be only three nights past full and very bright, so a telescope will be needed to see the leading bright edge of the Moon cover the star. Even the reappearance at the Moon's dark edge will still require at least binoculars because of the lunar glare. From Hawaii, the event happens soon after moonrise on Saturday, with moment of star's disappearance ranging from 9:06 p.m. HST (Hilo) to 9:11 p.m. (Lihue), and reappearance around 10:02 p.m. HST. From West Coast, the occultation begins early Sunday morning, at a time ranging from 12:43 a.m. PDT (Santa Barbara and San Diego) to 1:27 a.m. (Vancouver), and ends at a time ranging from 1:27 a.m. (Vancouver) to 2:01 a.m. (San Diego). Here are precise times of disappearance and reappearance of Aldebaran Sunday morning for several cities in southern Michigan (all times are a.m. EDT): Ann Arbor 4:52:43-6:10:56; Battle Creek 4:50:04-6:08:31; Detroit 4:54:02-6:12:02; Flint 4:53:15-6:10:16; Grand Rapids 4:49:38- 6:07:03; Jackson 4:51:27-6:09:54; Kalamazoo 4:49:18-6:07:51; Lansing 4:51:30-6:09:09. Along the East Coast, the occultation of Aldebaran begins Sunday morning at a time ranging from 5:00 a.m. EDT (coast of Georgia) to 5:16 a.m. (Miami) or 5:22 a.m. (eastern Maine), and ends at a time ranging from 5:59 a.m. EDT (Key West) to 6:31 a.m. (Cape Cod). In New England, twilight is bright as the star reappears. For more information on this event, see article, "The Moon Hits the Bull's Eye Again," in October 1997 Sky & Telescope, pp. 94-96., and on the website: http://www.skypub.com/whatsup/lunocc97.htm More in Skywatcher's Diary tomorrow. For times of disappearance and reappearance of Aldebaran for over 200 cities in U.S. and Canada, visit the website: http://www.sky.net/~robinson/1019al.htm Saturday, October 18 There are two unusual events for skywatchers tonight. The first is a striking compact straight-line arrangement of two planets and a star, best seen about an hour after sunset. Face SW and look for brilliant Venus, with Mars just over 3 degrees to upper left, and Antares 2-1/2 degrees to lower right. The line of three is less than 6 degrees long and easily fits within the field of view of 7-power binoculars. Tonight's second event is an occultation of Aldebaran by the Moon. In table below, the first time given for each city is when the star disappears behind the Moon's leading bright edge. The second time is when star reappears from behind the Moon's trailing dark edge. Honolulu 9:09-10:02 p.m. HST; Los Angeles 12:44-2:00 a.m. PDT; Vancouver 1:26-1:43 a.m. PDT; Tucson 12:51-2:13 a.m. MST; Salt Lake City 2:04-3:16 a.m. MDT; Denver 2:12-3:31 a.m. MDT; Austin TX 3:18-4:39 a.m. CDT; Kansas City 3:29-4:52 a.m. CDT; Chicago 3:45-5:04 a.m. CDT; East Lansing MI 4:51-6:09 a.m. EDT; Atlanta 4:51-6:12 a.m. EDT; Toronto 5:01 a.m.-6:16 a.m. EDT; Washington DC 5:05-6:24 a.m. EDT; New York 5:10-6:27 a.m. EDT; Boston 5:15 a.m.-6:29 a.m. EDT; Miami 5:16-6:08 a.m. EDT. In the hours leading up to the occultation of Aldebaran, several stars of the Hyades cluster will pop out from behind the Moon's dark side; for times for selected cities, see the article, "Lunar Occultation Highlights for 1997," in Sky & Telescope, Jan. 1997, pp. 89-92. For more on the Aldebaran event, see yesterday's Diary and articles and websites listed therein. Sunday, October 19 About 3-1/4 hours after sunset, depending on your location, the Moon rises in ENE about 10 degrees lower left of Aldebaran. By an hour before sunrise on Monday, Moon is high in SW, with Aldebaran 14 degrees lower right and Betelgeuse, Orion's shoulder, 11 degrees to Moon's lower left. Monday, October 20 Within an hour after sunset brilliant Venus, very low in SW, is flanked by Mars within 3 degrees upper left and Antares within 4-1/2 degrees lower right. Jupiter is bright in SSE, and Saturn is low in E. Tuesday, October 21 An hour before sunup on Wednesday, the Moon, approaching Last Quarter, is high in S. Procyon is 12 degrees below and a bit left. Pollux, the brighter Gemini twin, is 12 degrees above the Moon and a bit left. Castor, the other twin, is 4-1/2 degrees upper right of Pollux Wednesday, October 22 Within 6 hours after sunset tonight, the Last Quarter Moon rises in ENE 13 degrees lower right of Pollux. On Thursday an hour before sunup, Moon is in SSE, with Procyon 14 degrees lower right, and the Gemini twins Pollux and Castor, 15 to 19 degrees upper right. Thursday, October 23 An hour before sunup on Friday, the fat crescent Moon is high in SE, with Regulus, heart of Leo the Lion, 15 degrees to lower left. Friday, October 24 Venus and Mars appear closest this weekend, just over 2 degrees apart, with Mars to the brighter planet's upper right. Look very low in SW an hour after sunset. Binoculars help locate Antares 9 degrees to Venus' lower right. On Saturday an hour before sunrise, the Moon is high in SE. Regulus is within 3 or 4 degrees to Moon's left. Saturday, October 25 Remember to set your clocks back one hour tonight, if you have been observing Daylight saving time. On Sunday an hour before sunup, Moon is in ESE with Regulus, heart of Leo, within 10 degrees upper right. Sunday, October 26 On Monday an hour before sunup, Moon is in ESE with Regulus 21 degrees upper right, and Denebola, tail of Leo, 12 degrees upper left. Monday, October 27 From most of U.S. on Tuesday morning, the old crescent Moon rises nearly due east 2-1/2 to 3 hours before sunrise. Locate the Moon in ESE an hour before sunup, and notice the beautiful earthshine on the Moon's dark side. Also, note the bright star Arcturus very low in ENE. At this time of year, Arcturus can also be seen at dusk, very low in WNW. Tuesday, October 28 Four planets are easy to see at dusk: Briliant Venus very low in SW, with Mars just 2.3 degrees to its upper right; Jupiter just east of due south, some 50 degrees from Venus; and Saturn in E to ESE, 63 degrees E of Jupiter. Some 45 minutes before sunup on Wednesday, the last easy old crescent Moon of this cycle can be seen very low in ESE. Binoculars might show Spica about 9 degrees below. Spica is just emerging from Sun's glare; it was almost directly behind the Sun on Oct. 16. Wednesday, October 29 On Thursday about 45 minutes before sunrise, the very old crescent Moon has just risen 12 degrees S of east and 6 degrees lower left of Spica. Binoculars will come in handy for this very difficult sighting. From lower Michigan, Moon is less than 23 hours before New. Thursday, October 30 Moon is New overnight, on Friday morning at 5:01 a.m. EST (12:01 a.m. in Hawaii). Friday, October 31 Hawaii is the only place in the U.S. where the young Moon can be seen this evening. From there, 20 minutes after sunset, locate Venus well up in SW, and Mercury 3 degrees up in WSW, 36 degrees to Venus' lower right. The very thin crescent, just 18 hours after New, is 6 degrees to the right of Mercury. Viewers on the mainland will have to wait until early Saturday evening for their first view of the young crescent. 8:00 p.m. tonight: The Last Question, an Isaac Asimov sci-fi tale on the ultimate fate of the Universe, begins a 4-weekend run at Abrams Planetarium. Narrated by Leonard Nimoy. Shows are Fridays and Saturdays at 8:00 p.m. and Sundays at 4:00 p.m., through Nov. 23. The Digistar version of this public program was produced at Abrams Planetarium. Our show for adults and children of all ages, WSKY...Radio Station of the Stars, continues Sundays at 2:30 p.m., through December 21. Saturday, November 1 The young Moon is easy to see from mainland U.S. tonight, but folks in northern states need to look early! Half an hour after sunset, the thin crescent is very low in WSW, about 30 degrees lower right of Venus. As sky darkens, note Mars 3 degrees to Venus' upper right, bright Jupiter approaching its high point in south, and Saturn climbing in ESE. Sunday, November 2 The two brightest evening objects are low in SW at dusk: Moon with Venus about 20 degrees to its left. Using binoculars, can you still see Antares 9 degrees to Moon's lower left? Viewers in southern states should see it easily. Look about 40 minutes after sunset. Monday, November 3 An hour after sunset, Moon is in SW, with brilliant Venus about 10 degrees to its lower left. Faint Mars is within 3-1/2 degrees upper right of Venus. ***** end of Skywatcher's Diary for October 1997 *****