Bakersfield Night Sky – November 20, 2010
By Nick Strobel
Today's column is going to focus on what you'll see in the evening of Thanksgiving so you can show your family and friends what's up in the sky after (before?) you've feasted. In the early evening just after sunset look low in the southwest to see if you can spot Mercury with the dimmer Mars to the right of it. Both of them are in the inset of the attached star chart. Straight above the two planets are the summer constellations of Cygnus, Lyra, and Aquila that were high overhead in the southern sky in the evening three months ago are now lower in the west in late fall. Looking toward the west, the central part of Cygnus makes the shape of a cross standing upright. The top of the cross is the tail of the swan, Deneb and bottom of the cross is the swan's beak, Albireo. In the area of sky that is Cygnus' left wing (on the north side of the cross shape) is where the Kepler spacecraft is searching for other planets beyond our solar system. The search area is shown on the second star chart below.
The spacecraft was designed to have the sensitivity to detect Earth-size planets orbiting in the stars' habitable zones, the regions around the stars where the surface temperature is such that liquid water could exist on the surface. It is looking for Earth-size planets by looking for those that happen to cross in front of the star from our perspective and make the star get dimmer for one to several hours. Since most planets don't have their orbits so nicely lined up for us to see the orbits edge-on (and pass in front of their star), Kepler is looking at over a 100,000 stars non-stop to have a decent chance of finding some orbits edge-on. So far it has found 7 confirmed planets, though all of them are roughly the size of Jupiter. It has found over 7 HUNDRED planet candidates that need follow-up observations to confirm them as planets. If there are Earth-size planets out there, Kepler will be the first instrument capable of detecting them.
Bright Jupiter is already up in the southeast at sunset but the first star chart below shows the view at 7 PM when Jupiter is almost due south. Those of you with very dark skies and very good eyes might be able to see the much, much dimmer dot of Uranus to the left of Jupiter. Higher up almost directly overhead above Jupiter is the Great Square part of Pegasus, the flying horse. The horse is upside down on our sky so the neck and head come down closer to the horizon. Sticking out of the left side of Pegasus are the two strings of stars of Andromeda. Are you able to see the faint fuzzy patch of the Andromeda Galaxy (M31)? That is a spiral galaxy of about the same size as the Milky Way over 2.5 million light years away so we are seeing the Andromeda Galaxy as it was over 2.5 million years ago because light travels one light year of distance in one year of time. In the east you will see the gorgeous star cluster, The Pleiades, at the shoulder of Taurus rising up. How many of the Pleiades' stars can you pick out? Good eyes can see six and extremely good eyes can pick out more. Further north at about the same altitude above the horizon is the bright star Capella in Auriga.
A Waning Gibbous Moon will be visible in the east at about 10:30 PM on Thanksgiving evening. The bright star to the left of the Moon will be Regulus at the end of the sickle part of Leo. Really late night owls (or very early risers) will be able to see Saturn after 3 AM followed by super-bright Venus after about 4:20 AM. Saturn is brighter than the brightest star of Virgo called Spica. Spica is between Venus and Saturn. The third star chart below shows the view at 5 AM.
There are still tickets left for the holiday show "Season of Light" that will be given on the first two Thursdays of December (before we close for the winter break). Tickets must be purchased ahead of time from the BC Ticket Office. See the "Season of Light" link for more about this show, ticket prices, show times and map to the Planetarium and the BC Ticket Office.
Want to see more of the stars at night and save energy? Shield your lights so that the light only goes down toward the ground. See www.darksky.org for how.
Director of the William M Thomas Planetarium at Bakersfield College
Author of the award-winning website www.astronomynotes.com