Saturday 08/14/2010 Black Star Canyon star party
By: Steve Short
August 11, 2010 4:16AM PDT
Views: 3937

BSC - Saturday 14 August 2010
Hello Fellow OCA club members!

This Saturday I plan to open the gate about 7:15 pm, which is a half hour before the sun sets. The weather report for this Saturday indicates that Orange County will be sunny, warm (40% humidity) and clear.  The 3rd Quarter Moon will not rise until well after midnight giving us dark skies. 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.
The ISS (International Space Station) will not make any visible evening passes this Saturday but the HST (Hubble Space Telescope) will make a visible pass. The Mag 2.4 pass will start at 9 pm 10 degrees high SSW going to 20 degrees high at 9:03:18 South and then dropping out of sight.  There will also be one visible Iridium flare this Saturday at BSC, 08:23:58 pm 30 degrees high in the North (351 degrees) from Iridium Satellite 95 going from a magnitude -2 to -7.  I am sure we will also see a few dim satellites pass over as we are looking up in the sky but we will not see the secret USAF X-37B space plane I mentioned 2 months ago as it will only be visible in early morning passes.

~Mercury, (Mag 0.6) sets about 8:45 pm and is very low on the horizon so will be hard to see this Saturday evening. It is about 77 million miles from Earth in constellation Leo. Mercury will only be about 5 degrees above the horizon 30 minutes before sunset this month.
~Venus, (Mag -4.2) still dominates the sky after the sun sets and can be spotted  high in the West in constellation Virgo. It will not set until about 9:20 pm and is now about 70 million miles from our planet and getting closer. The Venus phase Saturday will be about 50% lit diminishing to 42% by month end when it will have a 28” diameter disk.

~Mars, (Mag 1.5) is now in Constellation Virgo and will be seen above Venus this Saturday evening at BSC.  It is about 190 million miles away, getting further every day and is only a small 5” disk. Mars won’t set until about 9:55 pm but is too far away to see any detail on the planet.

~Jupiter, (Mag -2.6) rises about 9:45 pm in constellation Pisces so the big planet can be seen this month from BSC. It now is about 390 million miles from Earth with a disc spanning 48” and getting a little closer every day. Closest moon Io will be alone to the East of Saturn Saturday evening while moons Europa, Ganymede and Callisto will be to the West in that order.

~Saturn, (Mag 1.1) sets about 9:45 Saturday in constellation Virgo so will  be visible less than 2 hours at BSC. Saturn is about 953 million miles away slowly moving further from Earth. Saturn will be above and to the right of Venus and with Mars nearby, they form a planetary trio. Saturn appears 16” across and the rings span 37”.

~ Uranus, (Mag 5.8) will rise about 9:30 pm in constellation Pisces this week and be about 2 degrees from Jupiter so both planets can be seen in the same binocular view. It shows up as a 3.7” blue-green disc in a telescope and is about 1.797 billion miles away moving closer to Earth.

~ Neptune, (Mag 7.8) is in constellation Aquarius, about 2.699 billion miles away this week slowly moving closer to Earth  It is seen as a bluish disc in a telescope and we should see it at BSC this Saturday evening as it rises about 8 pm. This planet currently lies near the spot where it was discovered by German astronomer Johann Galle September 23, 1846.


The Perseid meteor shower peaks Thursday night August 12th showing 60-100 meteors per hour but we may see a few leftovers Saturday.  The  radiant is between Persus and Polaris, the North Star. The meteors come from particles left by the Comet 109P/ Swift-Tuttle.


Comet 10P Tempel 2 (Mag 8.3) is in constellation Cetus just 10 degrees below Jupiter near the eye of the whale so could be seen at BSC this Saturday. It is just 61 million miles from Earth and has a period of 5.37 years. This comet travels between the orbit of Mars and Jupiter.

Comet C/2009 R1 McNaught (Mag 9.4) is in constellation Hydra and is about 169 million miles from Earth. I doubt that we will be able to see this comet which is seen half way between Mercury and the Sun. It was discovered by Rob McNaught September 9th, 2009 in Australia who discovered over 50 comets.


Minor Planet 4 Vesta (Mag 8.0) is the 2nd most massive object in the asteroid belt with a diameter of just over 329 miles. It is the brightest of all the asteroids and can be found just a few degrees directly above Saturn in constellation Virgo. It is now is about 266 million miles from Earth and has a period of 3.63 years.

Minor Planet 1 Ceres (Mag 8.2) can be found in constellation Ophiuchus about 10 degrees above the Scorpion stinger stars in a direct line between Antares and the Teapot lid’s top star.  It is about 206 million miles from Earth and has a period of 4.60 years. This is the largest asteroid having a diamater of about 580 miles.


Deep Sky:

This month, lets look at some famous galaxies and the Ring Nebula that was being shown to hundreds of people through the 24” scope at the UCI Observatory last Saturday at their Visitors Night:

M31 (Mag  3.5) the spiral Andromeda Galaxy will be visible Saturday evening after the Sun goes down and should be spectacular in the dark eastern sky. It is 2.5 million light years away with a diameter of about 120,000 light years. It is easy to find along the line of Beta Andromeda (Mirach) through Mu Andromeda and then on to the Andromeda Galaxy.

M51  (Mag 8.1) the Whirlpool Galaxy is about 37 million light years away with a diameter of  118,000 light years. It forms the base of a right triangle under Big Dipper Handle stars Alkaid & Mizar. The bright “Knot” off  it’s arm is the more distant galaxy NGC5195 which had interacted with M51 in the past.
M57 (Mag 8.8) also called the Ring Nebula is located midway between Gamma & Beta Lyrae stars in the Lyra the harp constellation near Vega. This gas cloud is from a red giant star that cast off it’s outer layers into space exposing its hot core, a white dwarf. It is the white dwarf which causes that planetary nebula to glow and look like a smoke ring.

 Don't forget to bring your gloves, coats & sweaters because it might 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,


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