This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of November 2010.
November 2010 Highlights * Comet 103P/Hartley 2 is still a naked eye object (though fading) under very dark skies * Jupiter dominates the eastern evening sky * Uranus remains within 3 degrees of Jupiter all month * Venus rockets into the morning sky * Leonids meteor shower has a weak peak on the 17th
Note: If anyone has pictures or observations of these objects/events and want to share them with my readers, send them to the Transient Sky at <firstname.lastname@example.org>.
Moon – The table below lists important lunar dates for the month, including the phases of the Moon and nights of lunar-planetary and lunar-stellar conjunctions.
Nov 1 - Moon 5° from Regulus Nov 4 - Moon 7° from Saturn and 3° from Spica Nov 5 - Moon 1° from Venus (but 12° from Sun) Nov 6 - New Moon Nov 7 - Moon 2° from Mars Nov 8 - Moon 3° from Antares Nov 13 - First Quarter Nov 16 - Moon 7° from Jupiter and 6° from Uranus Nov 21 - Full Moon Nov 21 - Moon 2° from Pleiades Nov 22 - Moon 8° from Aldebaran Nov 25 - Moon 9° from Pollux Nov 26 - Moon 4° from Beehive Cluster Nov 28 - Last Quarter Nov 28 - Moon 5° from Regulus
Mercury – Mercury pops above the southwestern horizon around mid-month for a relatively poor evening apparition for northern observers (it is a pretty good one for those south of the equator). For most of the month Mercury hangs out with Mars and Antares. At magnitude -0.4, it is much brighter than the ‘Red Planet’. This evening apparition will continue into December.
Nov 15 - Mercury, Mars and Antares can fit within a 5° circle Nov 20 - Mars and Mercury within 2° of each other
Mars – Mars has fun this month with conjunctions with Mercury and 1st magnitude star Antares. Unfortunately, you’ll need an ultra-flat and ultra-clear southwestern horizon to see any of this. For most of us, the current Martian apparition is over. For the next few months the planet will be on the far side of the Sun and out of view.
Nov 7 - Mars 2° from the Moon Nov 11 - Mars 4° from Antares Nov 15 - Mercury, Mars and Antares can fit within a 5° circle Nov 20 - Mars and Mercury within 2° of each other
Jupiter (and Uranus, too…) – ‘King of the Planets’ continues his reign as the uncontested ‘King of the Evening Sky’. though fading from magnitude -2.8 to -2.6, nothing but the Moon rivals it in brightness. Located on the Pisces/Aquarius border, Jupiter is easy to find in the south-south-east as it gets dark.
If you have a pair of binoculars or small telescope take a look at Jupiter. See if you can see any of its 4 bright Galilean moons or 2 large atmospheric belts. In addition, Jupiter is within 3.4° of +5.8 magnitude Uranus all month long.
Nov 16 - Moon within 7° of Jupiter and 6° of Uranus
Saturn – Saturn rises a few hours before the Sun. Located in Virgo, the ringed planet is a close match in brightness (mag +0.9) to the Spica, the brightest star in Virgo (mag +1.0). It’s rings are slowly opening up and are currently 9° from edge-on.
Nov 4 - Saturn within 7° of the Moon
Venus – After passing through inferior conjunction last month, Venus begins a 10-month stay in the morning sky. On Nov 1, Venus rises only a half an hour before the Sun in the eastern sky. By the middle of the month, it is up 2 hours before sunrise and 3 hours before sunrise by the end of the month. Unlike this year’s evening apparition which was poorly placed, Venus’ current stay in the morning sky will be a good one for northern observers.
Nov 5 - Moon 1° from Venus (but 12° from Sun)
Meteor activity is near a yearly maximum in October. The year is usually split in 2 with January through June having low rates with few major showers while July through December (really through the 1st week of January) have high rates with many major showers.
Sporadic meteors are not part of any known meteor shower. They represent the background flux of meteors. Except for the few days per year when a major shower is active, most meteors that are observed are Sporadics. This is especially true for meteors observed during the evening. During September, 10-16 or so Sporadic meteors can be observed per hour from a dark moonless sky.
Major Meteor Showers
Leonids (ORI) [Max Date = Nov 17, Max Rate = ~10-20 per hour]
The Leonids are the only November shower which can approach major shower status. Though this shower has produced some of the greatest meteor storms in history, in most year’s it produces a rather pedestrian 10-20 meteors per hour under dark skies. Now that we are 12 years removed from the last perihelion of Comet Tempel-Tuttle, the parent comet of the Leonids, rates should be low with little likelihood of any enhanced activity.
The following summary from the IMO 2010 Meteor Calendar states: “This year is not expected to produce enhanced rates, but theoretical work by Mikhail Maslov suggested peak ZHRs of ~ 20 might occur around November 17, 15h UT instead of at the usual nodal crossing time above [Nov 17, 21:15 UT]. ZHRs from that later possible peak are likely to be ~ 10–20. The waxing gibbous Moon will not set until 2 to 3 a.m. local time on November 17 across the mid-latitude globe (later moonsets for places further north). As the Leonid radiant rises usefully only around local midnight (or indeed afterwards south of the equator), there will still be plenty of dark-sky time between moonset and the onset of morning twilight to observe whatever happens this year. The ~ 15h UT peak timing would coincide with moonless skies from the extreme east of Russia east to Alaska and places at similar longitudes on the Pacific Ocean. The ~ 21h UT timing would favour locations at comparable longitudes to central-eastern Asia, from roughly India east to Japan/western Australia. Other possible maxima are not excluded, and observers should be alert as often as conditions allow throughout the shower, in case something unexpected happens.”
The Leonids appear to radiate from a spot in the ‘sickle’ of Leo. Like many showers, the radiant does not rise till after midnight and is not well placed until after 3 am.
Minor Meteor Showers
Minor showers produce so few meteors that they are hard to notice above the background of regular meteors. Starting this month, info on most of the minor showers will be provided on a weekly basis by Robert Lunsford’s Meteor Activity Outlook.
Additional information on these showers and other minor showers not included here can be found at the following sites: Wayne Hally’s and Mark Davis’s NAMN Notes, and the International Meteor Organization’s 2010 Meteor Shower Calendar.
Naked Eye Comets (V < 6.0)
Comet 103P/Hartley 2 – Comet 103P/Hartley 2 is now in retreat from the Earth and Sun. Though past peak brightness the comet starts the month only a few tenths of a magnitude fainter than at its best (around magnitude +4.7). By the end of the month the comet will have faded by a magnitude or more.
103P was discovered at Siding Spring Observatory (Australia) on March 15, 1986 by Malcolm Hartley. With an orbital period of 6.47 years, the comet’s orbit currently stretches from 1.06 AU to 5.89 AU from the Sun. Though not an especially big or active comet, this year it passes 0.12 AU from Earth on October 21 allowing the comet to get much brighter than usual.
The comet starts the month at a distance of 1.06 AU from the Sun and 0.14 AU from Earth. By mid-month it will be 1.09 AU from the Sun and 0.20 AU from Earth. At the end of the month, Hartley 2 will be 1.15 AU and 0.28 AU from the Sun and Earth, respectively.
Even though the comet is currently 4th to 5th magnitude and theoretically bright enough to be seen with the naked eye, in reality this is a difficult object to observe. With a coma diameter greater than 1° across, Under very dark skies the comet can be seen with the naked eye. For most of us under brighter skies, the comet is not visible naked eye object but is visible in small binoculars as a large (30’+) diffuse fuzz ball. Under my moderately light polluted sky (LM +5.5), the comet was a faint but easy object in 10×50 binoculars if you know exactly where to look. As always, the darker the sky the better.
The comet is still racing south along the winter Milky Way. It starts the month in southern Gemini before crossing through Canis Minor and Monoceros and ending the month in Puppis between the bright open clusters M46 and M47. It is a morning object and is highest in the sky before the start of dawn.
On November 4 the NASA EPOXI (ex-Deep Impact) spacecraft will encounter the comet giving us close-up views of the comet’s nucleus.
Binocular Comets (V = 6.0 – 8.0)
Small Telescope Comets (V = 8.0 – 10.0)
Binocular and Small Telescope Asteroids (V < 9.0)
(6) Hebe is a S-type asteroid with dimensions 205 x 185 x 170 km. Recent research suggests that it is the source of many ordinary chondrite meteorites and near-Earth asteroids.
This month Hebe is in Cetus and will fade from magnitude 8.4 to 9.0.