Expert: Tom Whiting - 12/22/2011

Question
My daughter and I were outside looking at stars, and we noticed a very sparkly star. Red and bluish, under Orion in the northeastern sky. We are in central Arizona and it is 9pm on December 21. Is this a star? If it is, which one or a planet.  We watched it for a while, and it never moved. So we know it isn't a plane. Thank you

Answer
Hi Jessica,
First, Orion is NEVER in our Northwestern sky. The constellation of Orion currently rises around
6 pm local time nearly due East, and sets in the due Western sky 12 hours later, around 6 am.
The bright bluish star in your northwestern sky around 7 pm is Vega, the summertime overhead star we see in June and July right overhead in the early evening sky.
Also, all planets follow the path of the sun in our sky... called the Ecliptic, or plane of the Solar System. So no planet is EVER in our NW sky, or Northern sky up by the dippers.
They all follow nearly the same path as the sun and moon do across our sky.  The bright planet now in the Southwestern sky right after sunset is Venus, climbing out from behind the sun. The only other bright planet (in our early evening sky) is Jupiter, nearly due south, high up at around 8 pm local time.
Hope this helps,
Clear Skies,
Tom Whiting
Erie, PA
PS... Oh, the sparkly or twinkling... is caused by turbulence in our atmosphere.  All changes of color, size, twinkling, anything out of the ordinary from a steady pinpoint, (like we'd see from the lunar surface with no air at all).... is all...atmospherics; along with colored sunsets, rainbows, orange or yellow rising full moons, haloes, sundogs, moondogs, sun pillars, circumzenithal arcs,  etc etc.  ALL are the atmosphere interfering with our view.

FOLLOW UP:
Opps... sorry, I misread your question, and I missed northeast for northwest. Ok, the bright star in the NORTHEAST at the time that Orion is rising in the EAST, is Capella (Alpha Aurigae)
a very bright zero magnitude star.  It arrives at your zenith (straight overhead) at 11 pm
local time. At that time the entire winter sky "Hexagon" is high in your south and beginning
from Zenith around to the west are Capella (at the zenith), Aldebaran in Taurus, Rigel in Orion's left foot, Sirius the dog star (brightest real star in our sky and southernmost of the Winter Hexagon), also called Alpha Canis Majoris.  Going back up the eastern side from Sirius,
we have Procyon (Alpha Canis Minoris), the Gemini twins Castor and Pollux, then back to Capella.  Notice that Betelgeuse (Right shoulder of Orion),  is enclosed by this large Hexagon, but not quite in the center.  Betelgeuse is a red supergiant... contrast its reddish color to Rigel, a blue-white supergiant star, both in Orion.
Hope this helps,
Clear Skies,
Tom