November 2007
Skywatcher’s Guide for November 2007
Comet Holmes
Previously small, faint Comet Holmes (designation 17P) has surprised astronomy observers around the globe by outbursting and suddenly becoming bright enough (at a visual magnitude rating of 2.5) to see with the naked eye on October 25. Click here for our news story to learn more.
PLANETS
Bright Jupiter is still visible in the November sky, but continues to lose altitude in our evening sky. Jupiter appears as a very bright, almost brilliant white star-like object, above the southwestern horizon in the early November evening twilight. By late November Jupiter moves very low into the southwestern sky and sets only one hour after sunset for Arizona (Jupiter is more difficult and setting earlier the farther north you live). Sinking in altitude this month, Jupiter sets above the southwestern horizon in southern Arizona by 8 p.m. in early November, by 7:00 p.m. mid-month, and at 6:30 p.m. in late November. To find Jupiter simply look for a very bright white star-like object above the south-southwestern horizon at 6:30 p.m. The largest planet in our solar system, Jupiter is the brightest star-like object most often seen in the night sky, although Venus is substantially brighter, and Mars can be brighter every 15 years or so. The giant gas world, although dimmed from June, remains bright in the evening skies of Earth all month long. Although it’s not a good time for looking at Jupiter in a telescope, the sharpest views should be in bright evening twilight, when it’s highest this month. As with any planet, viewing is dependent on atmospheric stability and conditions, and of course, the quality and size of the telescope used. However to view its moons, a good pair of binoculars is all that’s needed. Finally, the waxing crescent Moon can be seen well below Jupiter on the evening of Monday, November 12.
It’s now a good time for late night views of Mars. Mars brightens from -0.6 magnitude to –1.3 by November 31. While it brightens Mars also enlarges in apparent size from 12 to 15 arc seconds in size, so it’s well worth looking at in high quality telescopes at high power. In fact this month will be one of the best months to view Mars for several years to come. One hour before sunrise Mars is now overhead in Gemini, the Twins. It slows its eastward drift through Gemini, the Twins until becoming stationary on November 15. Mars starts retrograde or backward motion after this date. Mars is rising now above the east-northeastern horizon at around 9:30 p.m in early November but rises earlier each night, so that by mid-month it rises by 8:30 p.m. and by month’s end it rises at 7:25 p.m. The large waning, gibbous Moon can be found relatively close to Mars, and rising together in our evening sky on Tuesday, November 27.
Currently a Mars hoax e-mail might still be found making its way around the Internet, stating that Mars will be closest to the Earth in 60,000 years. Please go to our news story for more information.
The brilliant planet Venus remains our ‘morning star’ this month in the east. It was at greatest elongation from the Sun on October 28 and so gradually loses attitude in our morning sky. Even so rises over 3.5 hours before the Sun even in late November. Venus is a few degrees higher early in the month, at over 30 degrees in altitude about 1hour before sunrise. As Venus is now receding from Earth it slowly shrinks in apparent size in a telescope and its crescent now thickens. To the unaided eye Venus appears as an intensely bright white star that does not twinkle and is found high up in all month long above the eastern horizon, 45 minutes before sunrise. Venus is closest in the sky to the star Spica in the constellation Virgo on November 29/30: The waning crescent Moon is grouped wonderfully near Venus on Monday morning, November 5.
Saturn has left its dramatic grouping with Venus, but still is near (eight degrees from) the bright star Regulus in In the constellation Leo the Lion. Saturn appears as a closer to first magnitude star-like object (at magnitude 0.8), and is dimmer this year because its rings are more edge-on. Saturn was grouped near Venus from Oct. 1-21 but now Saturn continues to gain altitude while Venus will slowly sink out of view in the months to come. Saturn rises earlier and creeps higher in our sky and is very high overhead at dawn by the end of the month. The thick waning crescent Moon is grouped wonderfully near Regulus (and occults it-see below) but above Saturn on Saturday morning, November 3. The Moon is below or east of Saturn on November 4.
Mercury has a fine morning apparition and is easily visible to the naked eye in the northern hemisphere for much of November far below Saturn and near the eastern horizon. Mercury is best visible one hour before sunrise several degrees above the eastern horizon from November 1-21. The thin waning crescent Moon is nearest Mercury in our morning twilight sky on Wednesday, November 7 and Mercury is nearest the bright star Spica in Virgo from Nov. 2-7.
Visitors to Flandrau’s 16-inch telescope should note that Jupiter is too low in our sky for viewing. No bright planets are currently visible in the telescope during normal operating hours, but other celestial objects will be shown, weather permitting.. Flandrau’s main exhibit hall and planetarium are closed on Wednesdays but the telescope remains open, weather permitting Wednesday through Saturday nights (excluding select holidays). The telescope normally closes at 10 p.m.
Finally, remember that in spotting planets there is a general rule: ’stars twinkle, planets don’t’. This is because stars are point sources of light; therefore starlight is easily disturbed and shifted by air currents in the Earth’s atmosphere. However when looking at Mercury right now, note that it may appear to twinkle somewhat; however, this twinkling is of a slower nature than the bright stars.
An Occultation of Regulus on Nov. 3
A thick waning crescent Moon will cover (or ‘occult) and uncover the bright star Regulus, in Leo the Lion on Saturday morning November 3 for all of the Desert Southwest and California, most of Mexico and for many southern states west of Florida. For other parts of the United States (such as Florida) the disappearance or reappearance of Regulus may happen in bright twilight or daylight. Regulus is the brightest star in Leo and is found above Saturn in the pre-dawn hours right now. For Tucson and southern Arizona the disappearance of 1st magnitude Regulus behind the bright, day-lit limb of the Moon should occur at 3:38 a.m. (Mountain Standard or MST) with a reappearance at the edge of the dark, or night side of the Moon at 4:48 a.m. Times given by astronomers for occultations are predictions, observers should be set up and viewing the Moon at least 20 minutes before occultation times. Click here for a link to predictions for cities around the United States. This is an event best enjoyed in an amateur telescope, but can be seen in binoculars.
LEONID METEOR SHOWER WORTH WATCHING THIS YEAR
 This sky chart is useful around the United States but is most accurate for observers in the southern United States looking north-northeast around 2 a.m. from Nov. 16-19. |
The Leonid Meteor Shower, which peaks in the pre-dawn hours of November 17 and 18, will be not be affected much by the Moon this year (the Moon sets around midnight on Nov. 17/18). The Leonids, which have put on spectacular shows during 1998-2002, are known for producing greatly enhanced activity every 33 years as Earth plows through dense portions of the debris trail left by Comet Temple-Tuttle. Unfortunately, Earth has recently finished experiencing that 33 year cycle, so only greater than normal activity might occur this year. This year’s Leonids are not expected by astronomers to put on a bright show of thousands of meteors visible per hour. However, on the night of November 17-18, there is the possibility of an outburst of activity at around 11 p.m to midnight Eastern Standard Time (EST) for the East Coast of North America (but too early for Arizona and the Desert Southwest). This cautious prediction is due to the Earth having just passed through this period of increased activity (during 1998-2002), and because of recent observations of the dust trail left by parent Comet Temple-Tuttle. If astronomer’s cautious predictions hold true, the Leonids may show 10 to 40 meteors per hour on Saturday night Nov. 17 (into Sunday morning Nov. 18), but will probably display the usual maximum hourly rate of 10-15 meteors per hour (novices often see less than this number)
In any event the shower is well worth keeping an eye on, in case the Leonids prove to be as unpredictable as they have in the recent past. The radiant (that is the area of sky where the Leonids appear to originate from) rises at local midnight, so meteor watchers should start gazing at that time, and look until dawn. Sky gazers should be alert and outside during all the probable maximum dates from November 16-19 as unexpected meteor peaks may occur. The Leonids often produce brilliant fast meteors, so even a few bright Leonids like this are well worth seeing! Dark viewing locations are still highly recommended: glare from artificial light sources will certainly reduce the amount of meteors seen!
NOVEMBER STARS
In the western sky at the end of evening twilight anywhere in the U.S., stargazers can find the bright stars of the widely spaced triangle Summer Triangle: Vega, Deneb, and Altair. Because it’s November the Summer Triangle is losing altitude, and sets in the western sky around midnight (Altair sets at 11 p.m. mid-month). Vega, Altair, and Deneb are each the brightest stars of three constellations that make up the Summer Triangle. Vega is the brightest star in the small constellation of Lyra, the Lyre (a small ancient harp). Vega, one of the closer stars to Earth (at only 25 light years away), was the Pole Star (our North Star) some 12,000 years ago, and will again be the North Star in 14,000 A.D. when Earth’s cyclical wobbling motion brings in near the pole once more. Deneb is the tail of Cygnus the Swan, but also marks the bottom of the cross-shaped pattern whose other name is the Northern Cross. Deneb is a huge supergiant star over 1,600 light years from Earth. Aquila, the Eagle is the home of the bright star Altair, the first star of the three in the triangle to set late at night and the closest of the three to Earth at only 17 light years distant. Aquila looks more like a diamond or kite than an Eagle. Aquila and Cygnus (or the Northern Cross) mark some of the brightest areas of the northern Milky Way, which is prominent in dark skies on moonless November nights.
Remaining at center stage in November is the Great Square of Pegasus. Find the Great Square quite a ways up from Fomalhaut, the bright star marking the Southern Fish (Pisces Austrinus), which lies somewhat low in the south. The eastern corner star of the “Great Square” of Pegasus, Alpheratz, is actually also the head of Andromeda, the Chained Lady or Princess. In Andromeda, is the “Great Andromeda Galaxy”, M31, which can be viewed as a fuzzy spot in binoculars. Rising in the eastern sky (and far from M31) is the Seven Sisters (or Pleiades) star cluster, a wonderful sight in binoculars.
MOON PHASES
The November last quarter Moon will occur on Thursday morning, November 1st. The November new moon occurs on the night of November 9. The November first quarter Moon will occur on Saturday evening, November 17th. The November full Moon can be called the full ‘Beaver or Frosty’ Moon and rises on Friday evening November 23rd and sets Saturday morning November 24th.
Note: Additional information can be accessed by phone at Flandrau Science Center’s Astronomy Newsline at (520) 621-4310 or as a menu option at 621-S-T-A-R.
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