Download Mountain Skies - Pisgah Astronomical Research Institute

 PISGAH ASTRONOMICAL RESEARCH INSTITUTE Text by Dr. Bob Hayward Astronomer/Educator Star Map by TheSky Software Bisque Mountain Skies January 2, 2017 ORION DOMINATES THE EVENING SKY The stars: Winter is truly here now, marked for the astronomer, not by the errant snow shower, but by the inevitable appearance of Orion the hunter in the evening skies. Orion dominates the skies in the winter as does no other constellation in any other season. With his seven bright stars, especially the three in a row that mark his famous belt, he is easily spotted as he rises in the east in the early evening. The three bright stars of his belt form a conspicuous line. From east to west they are Alnitak, Alnilam and Mintaka. To the north of his belt lie his shoulders in the bright red supergiant star Betelgeuse to the east and fainter Bellatrix as his western shoulder. To the south are his knees marked by Saiph on the east and the blue-­white Rigel on the west. Look closely at the three fainter stars hanging below his belt. This is the sword of Orion. Gaze in particular at the middle star and you will notice it is a bit fuzzy;; it is called the “smoking star” in some Native American traditions. A pair of binoculars or a telescope reveals this to be the beautiful “Great Nebula of Orion,” an immense cloud of gas in which stars are currently forming. To the astronomer this nebula is known as Messier 42 or M42 since it was object no. 42 in a catalog of faint, fuzzy objects compiled a little over 200 years ago by the French comet hunter Charles Messier. His catalog, ironically, was a list of objects not to look at if you were looking for comets. Generally, when comets are first discovered optically, they appear as faint, fuzzy objects that move against the pattern of background stars. The objects in Messier’s catalog looked very much like comets but didn’t move! Now the Messier objects are famous as nebulae, galaxies and star clusters. The planets: The brilliant planet Venus continues to serve us as our “Evening Star” high in the west as the sky darkens. On the 12th it will reach its greatest elongation when it is a full 47° east of the setting sun. Now, don’t get confused;; when Venus is east of the sun we spot it in the west after the sun sets. The reverse is true when Venus is our “Morning Star” rising in the east before the sun. That will be the situation beginning about April Fool’s Day. As you watch Venus set in the west these evenings, turn around and note the Dog Star Sirius rising in the southeast. Sirius is the brightest star in the nighttime sky and you can see that Venus is indeed brighter. Mars is still hanging around in the southwest at sunset. It is just above and to the left of Venus but not anywhere near as bright as the queen of the planets. Recognize Mars by its reddish coloration and the fact that, like all planets, it doesn’t twinkle. All month long Venus and Mars will be holding this pattern in the southwest as they move across Aquarius the water bearer and into Pisces the fish. This formation will continue until early March when Venus dives into the evening twilight to pass by the sun on March 25 and emerge in the morning twilight as mentioned above. The king planet Jupiter is now in our morning skies rising a few minutes after 1 a.m. By dawn it is well up in the east and serves us as our current “Morning Star.” Jupiter is the second brightest of the planets yet still brighter than any star in the nighttime sky. If you are up at this time of the morning, note the Dog Star Sirius setting in the southwest as Jupiter rises and you will note that Jupiter is brighter than any nighttime star. The ringed planet Saturn and the elusive Mercury are both rising in the southeast before the sun. Saturn is visible in the morning twilight. However, Mercury is below Saturn and hard to spot. Give it another week to rise higher before dawn and it will be well up for the rest of the month. Celestial Calendar: January 3, 9 a.m. EST – Quadrantid meteor shower peaks January 5, 2:47 p.m. EST – First Quarter Moon January 11, 6:34 a.m. EST – Full Moon January 19 -­ The Sun in its annual path around the sky passes from Sagittarius the archer into the fainter constellation of Capricornus the sea-­goat.