Sky this Week

Highlights Dec 30 to Jan 5

• 8P/Tuttle very close to Messier 33 (if not within) early Sunday evening
• Dark sky weekend coming up
• Bright ISS passes early in the morning this week (see below for Denver times)
• Earth at perihelion (closest to the Sun) on Thursday, Jan 4 at 4 pm MST distance 0.983 a.u. (91.4 million miles)

International Space Station

Some good passes this week, but you’ll have to get up before sunrise to see them.
On Sunday Dec 30 the ISS appears at 06:59:47 am in the SSW and disappears at 07:05:00 am in the ENE (magnitude -0.4)
On Monday Jan 1 the ISS appears at 06:06:16 am in the SSW and disappears at 06:11:19 in the ENE (magnitude -0.4)
On Thursday Jan 3 the ISS appears at 06:47:31 in the West and disappears in the NNE at 06:52:28 am (magnitude -1.3)
On Friday Jan 4 the ISS appears at 05:36:15 halfway up in the sky in the NE and disappears at 05:38:20 in the NE (magnitude -1.5)
On Saturday Jan 5 the ISS appears in the North at 05:56:36 and disappears in the NE at 05:58:38 am (magnitude -1.1)

Sun

No regions are currently visible as of today. Solar activity is expected to remain at very low levels this week.

Moon

The moon is in last quarter early Monday morning, Dec 31 at 0:51 am MST. It will be “new” a week from Tuesday.

Planets

Mercury appears very low in the southwest a half hour after sunset late in the week. It will be in better position next week.

Venus is very bright at magnitude -3.95 and 14.2 arc sec across. It moves from constellation Libra into constellation Scorpio on New Years day.

Mars dims a bit this week from -1.6 to -1.4 magnitude in brightness. Our view of the martian disk shrinks from 15.55 arc sec Sunday to 15.1 arc sec next Saturday. However it is still a good time to view Mars. Seeing It is detail visually through an eyepiece is difficult unless seeing conditions are very good. Use as much magnification as conditions permit and experiment with red and green filters to reduce the glare. To get the best view, replace the eyepiece with a webcam and view it on your laptop. Later process the video with Registax and you should be able to identify some features.

Saturn is in constellation Leo. It rises just after 9 pm by Saturday and is +0.9 magnitude in brightness. The disk is 19 arc sec across.

Dark Sky

Dark sky weekend is here once again! The truly dedicated can get 11 hours and 21 minutes of astronomical darkness Saturday evening.

Take a look directly south around 10 pm about half way up in the sky and locate “Orion, the Hunter”. Look for three bright, second magnitude stars in straight line from the southeast to the northwest. These stars form Orions Belt. To the upper left is the reddish 0.5 magnitude star Betelegeuse. Toward the upper right is the 1.6 magnitude bluish star Bellatrix. Below are two other bright stars, 2nd magnitude “Saiph” on the left and magnitude 0, “Rigel” on the right.

Use binoculars and center on the middle belt star called “Alnilam”. Surrounding it is a magnificent sprinkling of about a hundred stars from 5th to 10th magnitude in a 3 degree field called “Collinder 70″.

Drop southward from the middle star and locate Orion’s sword. This region is the location of one one of the night skys most splendid show pieces, the Great Orion Nebula. This is one of everyone’s favorite objects to view in a telescope of about any size. In the center of the region are four bright stars forming a diamond shaped asterism called the “trapezium”. In steady skies a couple additional 10th magnitude stars may be seen. Just above M42 is another diffuse nebula, “Messier 43″ which surrounds an irregular variable star “NU Orionis”. If you are fortunate have dark skies, continue exploring another 30′ north and view some of the faint nebulous swirls of NGC 1973-1975-1977. This region is a continuation of the same large cloud of dust surrounding the Orion nebula. If conditions are really good, point your scope toward the left most star in Orion’s belt, “Alnitak”. Move north and east until Alnitak is just out of field and view the NGC 2024, the “burning bush” or “flame nebula”. If you center on Alnitak and then slew straight south, you may be able to see the elusive “horse head” nebula, IC434 or Bernard 33, use UHC or OIII filter.

Comets

Comet 17P/Homes is in constellation Perseus, above and west of star Algol. It is around magnitude 5 in brightness and 70 or so arc minutes across.

Comet 8P/Tuttle is projected to be around magnitude +5.7. As soon as its dark on Sunday night, Dec 30 it should very close if not within Messier 33 in constellation Triangulum. It moves to southern Pisces on Saturday (just above Alrisha or Alpha Pisces).

See http://cometchasing.skyhound.com for charts and more information regarding comets.