Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2003 February 7 
Posted on 02/07/2003 5:40:29 AM PST by petuniasevan
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2003 February 7
Explanation: Orion, the Hunter, is one of the most easily recognizable constellations in planet Earth's night sky. But Orion's stars and nebulae don't look quite as colorful to the eye as they do in this lovely photograph, taken last month from Vekol Ranch south of Phoenix, Arizona, USA. The celestial scene was recorded in a five minute time exposure using high-speed color print film and a 35mm camera mounted on a small telescope. In the picture, cool red giant Betelgeuse takes on a yellowish tint as the brightest star at the upper left. Otherwise Orion's hot blue stars are numerous, with supergiant Rigel balancing Betelgeuse at the lower right, Bellatrix at the upper right, and Saiph at the lower left. Lined up in Orion's belt (left to right) are Alnitak, Alnilam, and Mintaka all about 1,500 light-years away, born of the constellation's well studied interstellar clouds. And if the middle "star" of Orion's sword looks reddish and fuzzy to you, it should. It's the stellar nursery known as the Great Nebula of Orion.
Where I live, at 45 degrees north latitude, I can find Orion at some point during the hours of darkness from late August early mornings to mid May late evenings.
Of course Orion will appear "upside down" in orientation to Southern Hemisphere observers.
Also, if you are looking for a rising or setting Orion, be advised that it will seem to be lying on its side.
A great way to get acquainted with various constellations and their times of visibility is to download or purchase software for the purpose. Some programs are freeware or shareware, and some cost a little or a lot. It depends on what you're after.
Here's a link to dozens of programs.
Astronomy Software: Freeware, Shareware, and Commercial Software
I have used CyberSky shareware; it's pretty good. If you don't mind paying (quite) a few bucks, I recommend highly the Starry Night software. I use the Pro version; it also comes in Beginner and Backyard versions. To me it's worth every dollar I paid for it.
Here is a graphic image of Scorpius:
I recommend a simple book on stargazing, and perhaps one of the astronomy software programs listed at the link I mentioned in post 1.
I welcome questions - I may be a bit getting back to you, as I work rotating shifts. FReepmail me if you like.
Plane of the ecliptic (zodiac): Simply the plane in which the planets orbit the sun. From Earth they appear to follow a narrow path through certain constellations; those are termed the zodiacal constellations. There are 13 (not 12) such constellations: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces, and Ophiuchus.
A constellation is nothing more than a RANDOM GROUPING of stars at vastly DIFFERENT distances (and VAST distances indeed). The apparent passage of planets through those parts of the sky which contain certain star patterns does NOTHING to influence events on Earth.
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