Saturday 10/29/11 Black Star Canyon star party

Posted On October 26, 2011

BSC Star Party Notice  Saturday October 29th, 2011


Hello Fellow OCA club members!


This Saturday, I plan to open the gate around 5:30 pm, which is about a half hour before the sun sets. The weather report for this Saturday indicates that Orange County will be warm again, with humidity at just 15%. But keep an eye on the OCA website where I will post a notice on the home page should the star party be cancelled for any reason.


The new moon will be Wednesday so we should have fairly dark skies Saturday. 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 Ranch Conservancy property rule)



The ISS (International Space Station) will not make any visible passes Saturday evening but the HST (Hubble Space Telescope) will make two passes. The first  visible magnitude 1.8 HST pass Saturday evening will start at 6:33:52 pm 10 degrees high WSW going to 40 degrees high S at 6:37:52 and then dropping back to 10 degrees ESE at 6:41:52 pm. The second magnitude 2.7 pass will start at 8:15:32 pm WSW 10 degrees high going to 25 degrees high SW at 8:18 where it will fade out of sight. We will not see any Iridium flares Saturday evening but I am sure we will see a few dim satellites pass over as we are looking up in the sky.

Planets & Pluto:

~Mercury, (Mag -0.3) doesn’t set until 6:55 pm so might be seen this Saturday evening low on the horizon just under brighter Venus. It is about 123 million miles from Earth in constellation Libra, is 85% lit with a 5″ diameter disk.

~Venus, (Mag -3.8) might be seen Saturday evening as it sets about 7 pm, long after the Sun, in constellation Libra, and is very bright. Venus is now about 149 million miles from Earth, is 94% lit with an 11″ disk.

 ~Mars, (Mag 1.1) is now in Constellation Leo setting about 3 pm so cannot be seen this Saturday evening. It rises about 1:30 am so can be seen in the morning sky. It is about 152 million miles away, just a 6″ disk so still too far away to see any detail on the planet. Saturday, Mars is just 5 degrees from 1st magnitude star Regulus, the brightest star in Leo.

~Jupiter, (Mag -2.8) will rise about 6:20 pm in constellation Aries so will be seen all night long at the Saturday evening BSC star party. It now is about 370 million miles from Earth getting a little closer every day until its closest approach October 27th when it will be 369 million miles away. It will outshine any other object in the sky and moon Callisto will be far east of the big planet with Europa about half as far.  Moon Io will be to the west of Jupiter while Ganymede will be more than twice as far west.

~Saturn, (Mag 0.7) sets about 5:45 pm Saturday in constellation Virgo and will be so low in the sky near the Sun that it cannot be seen at the BSC star party.  Saturn is about 991 million miles away slowly moving further from Earth.

~ Uranus, (Mag 5.7) will be visible as the sun sets this week in constellation Pisces so can be seen Saturday evening at BSC. It will not set until 4:45 am and shows up as a small 3.7″ blue-green disc in a telescope. It is about 1.787 billion miles away, moving away from Earth. Uranus is easy to find using the two stars on the eastern edge of the Great Square of Pegasus and look along that line 15 degrees south.

~ Neptune, (Mag 7.9) is in constellation Aquarius, about 2.748 billion miles away this week slowly moving farther from Earth. It is seen as a bluish gray 2.3″ disc in a telescope and we should be able to see it at BSC this Saturday evening, as it rises about 3 pm and doesn’t set until 2 am.  

~ Pluto, (Mag 14.1) rises at 11:50 am and reached opposition and peak visibility in late June. It is 3.027 billion miles from Earth in constellation Sagittarius slowly getting farther from Earth. Since it is so dim, you will need a 10″ or larger telescope to see it visually at BSC until it sets at 10 pm.  The 2011 July issue of Sky & Telescope Magazine shows the path Pluto is following on page 64.



The October Orionids meteor shower peaked on the 21/22nd when one might have seen up to 20 meteors per hour under favorable conditions. The radiant was 10 degrees above Betelgeuse from debris left by Comet 1P/Halley. We normally see a few stray meteors at every BSC star party even when no meteor shower is expected.



The brightest comets visible right now are too close to the Sun to be seen. Several are near Venus and Mercury.


But one bright magnitude 7.9 Comet C/2009 P1 Garradd is near constellation Hercules so might be viewed this Saturday evening. The comet is heading northwest and if it brightens as expected, it will become visible to the naked eye in early 2012. It is now 181 million miles from Earth and can be found west of the Summer Triangle Altair/Vega side at the point that forms a right triangle with Vega and Altair outside the triangle.


Another brighter magnitude 7.4 Comet C/2010 X1 Elenin is in Gemini. It is only 24 million miles from Earth and can be found just below Castor along the twins body where the arms are connected.


Brightest visible asteroids:

Minor Planet 4 Vesta (Mag 7.4), the 2nd most massive object in the asteroid belt, can be found at the bottom of constellation Capricornus.  Vesta has a diameter of about 330 miles and was discovered in 1807. It is about 180 million miles from Earth at this time and has an orbit period of 3.63 years. It should become visible shortly after sunset so might be seen at the BSC star party up to 10 pm. NASA’s Dawn spacecraft has just gone into orbit around this asteroid and will study it for a year getting as close as 110 miles from its surface.


Minor Planet 1 Ceres (Mag 8.2) is the biggest object in the asteroid belt with a diameter of about 590 miles. It is in constellation Aquarius and can be found between the Whale’s head and Aquarius. Ceres is about 203 million miles from Earth and has a period of 4.60 years. It was discovered in 1801 and for 50 years was classified as the 8th planet. It will be visible Saturday evening after the sun sets up to midnight so might be seen at the BSC star party. This asteroid will be the next stop for the Dawn spacecraft.


Deep Sky:

This month let’s consider looking at some galaxies in the Andromeda area:


M31 (Mag 3.5) is the famous Andromeda spiral galaxy discovered by Simon Marius in 1712. It is 2.4 million light years away, contains about 300 billion stars and spans at least 120 light years. To locate this object, use the Mu & Beta Andromedae stars. The galaxy is in line with these stars and is as far away from Mu as Mu is from Beta.


M32 (Mag 8.2) is a dwarf elliptical galaxy Messier first observed in 1757. It is also 2.4 million light years away and is about a Moon’s diameter from the center of M31. It spans at least 5,600 light years.


M110 (Mag 8.0) is an elliptical galaxy that Messier first observed in 1773. It is also 2.4 million light years away and spans at least 12,000 light years.  It is also about a Moon’s diameter from the center of M31 somewhat opposite from M32.


M33 (Mag 5.7) is a spiral galaxy called the “Pinwheel Galaxy” is in the opposite direction from M31 following a line from Mu to Beta twice that distance in the Triangulum constellation.  It is 2.2 million light years away and has a diameter of 40,000 light years.




Don’t forget to bring your gloves, coats & sweaters because it can get cold after the sun sets and the night approaches midnight when we close. After you