Saturday 09/04/2010 Black Star Canyon star party

Posted On September 1, 2010

BSC – Saturday 4th September 2010
Hello Fellow OCA club members!

This Saturday I plan to open the gate about 6:45 pm, which is a half hour before the sun sets. The weather report for this Saturday indicates that Orange County will be sunny, warm (30% 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.

   Warning:  No Pets allowed!
The ISS (International Space Station)  and the HST (Hubble Space Telescope) will not make any visible evening passes this Saturday.  There will not be any visible Iridium flares this Saturday at BSC, but I am sure we will see a few dim satellites pass over as we are looking up in the sky. But we will see the secret USAF X-37B space plane as it will make a Mag 4.2 pass at 8:20 pm 10 degrees high in the South rising to 16 degrees SSE at 8:21:50 where it will fade from view.

~Mercury, (Mag ??) sets about 7:15 pm so will not bee seen this Saturday evening. It is about 58 million miles from Earth in constellation Leo. Mercury rises just before 7 am but might be spotted in the morning as early as September 13th just 6 degrees below Regulus but will be a dim Mag 1.0 just 21% lit. By September 19th it will brighten to Mag -0.4 as it rises 1 hour before the Sun.
~Venus, (Mag -4.3) still dominates the sky after the sun sets and can be spotted  high in the West in constellation Virgo. It will set about 9 pm and is now about 55 million miles from our planet and getting closer. The Venus phase Saturday will be about 39% lit diminishing to 19% by month end when it will have a 45″ diameter disk.

~Mars, (Mag 1.5) is now in Constellation Virgo and will be seen above Venus and to the right this Saturday evening at BSC.  It is about 200 million miles away, getting further every day and is only a small 4″ disk. Mars won’t set until about 9:45 pm but is still too far away to see any detail on the planet.

~Jupiter, (Mag -2.7) rises about 8:20 pm in constellation Pisces so the big planet can be seen this month from BSC. It now is about 373 million miles from Earth 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 1.0) sets about 8:30 Saturday in constellation Virgo so will only be visible for about an hour at BSC. Saturn is about 971 million miles away slowly moving further from Earth. Saturn will be about 20 degrees to the right of Venus and about half the brighter planet’s altitude.

~ Uranus, (Mag 5.7) will rise about 8:10 pm in constellation Pisces this week and be about 1 degree north 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 1.781 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 6:45 pm. This planet currently lies near the spot where it was discovered by German astronomer Johann Galle September 23, 1846.


The Alpha Aurigids meteor shower peaks Wednesday night September 1st showing just 6 meteors per hour so we probably won’t see any leftovers Saturday.  The  radiant is just below Capella in constealltion Auriga. The meteors come from particles left by a comet that crosses the Earth’s path every 1,000 years. But we do normally see a few stray meteors at every BSC star party.


Comet 10P Tempel 2 (Mag 8.8) is in constellation Cetus now 15 degrees below Jupiter and between Tau Ceti (corner of the whale’s mouth) and the bottom of the whale’s jaw 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 2P Encke (Mag 9.5) is in constellation Corvus and is about 104 million miles from Earth. The comet has a 3.3 year period and is directly between Virgo & Corvus but may be hard to see due to the setting Sun’s glare.


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 along the neck of the Virgin just 5 degres east of Saturn in constellation Virgo. It is now is about 278 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 232 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 globular clusters in and around Sagittarius:

M55 (Mag  7.0) is all alone far below the Teapot’s handle and therefore seldom visited by many astronomers. It is 20,000 light years away and has a diameter of 111 light years. The compactness of the stars are very loose compared to other globular clusters.

M54  (Mag 7.6) is just off the Teapot’s handle along the bottom of the Teapot just 1.5 degrees from Zeta Sagittarii. It is 89,000 light years away and has a diameter of about 220 light years. Unlike M55, this globular cluster is compacted very tight.
M70 (Mag 8.1) is half way between Zeta Sagittarii and Kaus Astralis along the bottom of the Teapot. It is 29,000 light years away and has a diameter of 67 light years. This cluster is fairly compact and has a string of 9th magnitude stars to the south.

 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,