BSC - Saturday 11th December 2010
Hello Fellow OCA club members!
This Saturday I plan to open the gate about: 4:15 pm, which is about a half hour before the sun sets. The weather report for this Saturday indicates that Orange County will be sunny, warm (35% humidity) and clear. The moon will be ¼ lit Saturday evening setting about 10:40 pm. First time visitors might want to get to BSC while it is still light so they can find their way down the dirt road and into the parking area. Remember that you take the 2nd farm gate on the left after turning on Black Star Canyon Road (the 1st farm gate is the Xmas Tree farm). If you come in after dark, you should drive in with your headlights off!!! The dirt road will be marked with red flashers and you can hold a flashlight out the driver’s window to light up the road directly in front of your car.
Warning: No Pets allowed! (This is an Irvine Nature Conservancy property rule)
The ISS (International Space Station) will not make any visible evening passes this Saturday. Also the HST (Hubble Space Telescope) will not make any visible passes Saturday evening and there will not be any visible Iridium flares, but I am sure we will see a few dim satellites pass over as we are looking up in the sky.
~Mercury, (Mag 0.1) sets about 6 pm so might be seen this Saturday evening at sunest very low on the horizon. It is about 80 million miles from Earth in constellation Sagittarius.
~Venus, (Mag -4.5) will not be seen this evening as it sets at 2:30 pm but can be seen in the morning as it rises about 3:20 am and is high in the sky (30 degrees) in constellation Virgo at sunrise. It will be very bright even though only about 30 percent illuminated going from 24% to 45% in December while it’s angular diameter will go from 42” to 27”. It is now just 42 million miles from Earth.
~Mars, (Mag 1.3) is now in Constellation Sagittarius setting about 5:40 pm just a few degrees below much brighter Mercury. It is about 220 million miles away, still too far away to see any detail on the planet. We should be able to spot the red planet Saturday evening just after sunset.
~Jupiter, (Mag -2.3) will not set until just after midnight and is so bright that it will become visible in constellation Aquarius as the sun sets. It now is about 440 million miles from Earth getting a little further every day. We should still see lots of detail on the big planet including the North Equatorial Belt (NEB) and just a thin dark SEB line, since that belt is still obscured by something. Largest moon Ganymede and smallest moon Europa will be close together to the east of Jupiter Saturday evening while on the west, will be moon Io and then Callisto much farther away.
~Saturn, (Mag 0.9) sets about 1:30 pm Saturday in constellation Virgo so will not be visible at the BSC star party. Saturn is about 932 million miles away slowly moving closer to Earth. The ringed planet will rise around 1:45 am and is high above Venus at sunrise. By the end of December, the ring will be tilted 10 degrees for the first time in almost 3 years.
~ Uranus, (Mag 5.8) will set 30 minutes after midnight this week, 15 minutes after Jupiter, in constellation Pisces and will be about 3 degrees east of Jupiter so both planets can be seen in the same binocular view. It shows up as a small 3.5” blue-green disc in a telescope and is about 1.850 billion miles away moving further from Earth.
~ Neptune, (Mag 7.9) is in constellation Capricornus, about 2.822 billion miles away this week slowly moving farther from Earth It is seen as a bluish 2.3” disc in a telescope and we should see it at BSC this Saturday evening as it does not set until 10 pm.
We will miss the Geminid meteor shower Saturday as it will peak December 14th but is still good the day before and after. The radiant is just above Castor and the best viewing will be at 3 am where one might see 100 per hour under dark skies. We normally see a few stray meteors at every BSC star party even when no meteor shower is expected.
Comet 103P Hartley (Mag 7.7) is in constellation Puppis and is only about 30 million miles from Earth. The comet has a 6.46 year period and on Saturday evening will be 10 degrees due east from Sirius so binoculars aimed there should pick it up.
Minor Planet 7 Iris (Mag 8.6) is the 4th brightest object in the asteroid belt with a diameter of about 125 miles. It is in constellation Cancer making a loop just a few degrees north of M67 so should be easy to find this month. Iris is about 123 million miles from Earth and has a period of 3.68 years. It was J.R. Hind’s first asteroid discovery made on August 13, 1847.
Minor Planet 6 Hebe (Mag 9.1) is another object in the asteroid belt with a diameter of just over 120 miles. It was once much bigger but a collision formed many pieces that have fallen to Earth. Astronomers think that 40% of Earth’s meteroites came from Hebe. It is in constellation Cetus just in front of the Whale’s head about 15 degrees below Jupiter and 10 degrees east. Hebe is about 138 million miles from Earth and has a period of 3.78 years.
Minor Planet 1 Ceres (Mag 9.2) can be found in constellation Sagittarius just 5 degrees due east of the Teapot’s handle. It is about 345 million miles from Earth and has a period of 4.60 years. This is the largest known asteroid having a diamater of about 580 miles. Current research indicates it contains a large volumn of water, enough to fill every fresh water lake and river on Earth.
This month, lets look at the Messier Trio open clusters in Auriga:
M38 (Mag 6.4) is an open cluster found as the apex of an isosceles triangle inside of Auriga’s pentigon Beta and Theta stars. It is about 4,000 light years away and has a span of about 20 light years. It contains about 100 stars with the brightest having a magnitude of 9.5, but with a small scope one only sees about 7 or 8 stars. It has an age estimated to be 220 million years and Messier discovered this object in 1764. Fainter cluster NGC 1907 is 30’ away.
M36 (Mag 6.0) is another open cluster found in the apex of a shallow isosceles triangle inside of Auriga’s pentigon Beta and Theta stars. It is thought to be 3,700 light years away and has a span of 13 light years. It contains about 60 stars with the brightest shining at a magnitude 8.9 and most can be seen with a small scope. It’s age is estimated to be 25 million years and Messier first observed this object in 1764.
M37 (Mag 5.6) is another open cluster found in the apex of a shallow isosceles triangle just outside of Auriga’s pentigon Beta and Theta stars. It is thought to be 4,200 light years away and has a span of 29 light years. It contains about 150 stars with the brightest shining at a magnitude 9.2 and there is a bright red star in the middle of this cluster. It’s age is estimated to be 300 million years and Messier first observed this object in 1764.
Don't forget to bring your gloves, coats & sweaters because it will get cold after the sun sets and the night approaches midnight when we close. After you set up your telescope, there are three picnic tables where you can sit and eat food you might bring, while waiting for it to get dark. Please remember to cart off all your trash as there are no garbage cans at BSC. Hope to see you there.
Your OCA star party host,