Saturday August 11th Black Star Canyon star party

Posted On August 8, 2012

BSC Star Party Notice  Saturday August 11th, 2012


Hello Fellow OCA club members!


This Saturday, I plan to open the gate around 7:15 pm, which is about a half hour before the sun sets. The weather report for this Saturday indicates that Orange County will be sunny, hot and very clear.  But keep an eye on the OCA website “Home” page (below the next speaker info) where I will post a notice should the star party be cancelled for any reason as that area could be closed due to high fire danger.


We should have dark skies as the last quarter Moon will not rise until after midnight Saturday. First time visitors might want to get to the star party site 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 OC Parks and Nature Conservancy rule).



  The ISS (International Space Station) will make one magnitude 0.2 visible pass Saturday evening starting at 8:49:57 pm 10 degrees high NNW for just 20 seconds.

  The HST (Hubble Space Telescope) will also make two visible passes Saturday evening. The first magnitude 2.1 pass will be at 8:12:30 pm WSW 10 degrees high going SSW 30 degrees high at 8:16:13 and then dropping back to 10 degrees high SE at 8:19:57. The second magnitude 3.5 pass will be at 9:55:30 pm SW 10 degrees high going SW to 11 degrees at 9:55:47 where it will fade out of sight.

  We will not get to see any Iridium flares Saturday evening at BSC. But I am sure we will see a few dim satellites pass overhead as we are looking up in the sky.


Planets & Pluto:

~Mercury, (Mag 2.3) sets at 6:40 pm so will not be seen this Saturday evening. It is about 65 million miles from Earth in constellation Cancer with about a 9″ diameter disk. It rises 80 minutes before sunrise so might be spotted just above the horizon about 15% lit.

~Venus, (Mag -4.2) will not be seen Saturday evening as it sets about 4:40 pm in constellation Orion. Hope you did not miss the rare Venus transit that occurred June 5th. Venus is now about 60 million miles from Earth and can be seen before dawn as it rises at 2:50 am in the Hunter’s raised arm. On Saturday morning Venus should be 50% lit with a 25″ disk.

 ~Mars, (Mag  1.1) is now in Constellation Virgo rising about 11:20 am so is visible high in the sky as the sun sets until 10:35 pm. Star Spica and planet Saturn will all be about in a straight line with Mars, all within a 5 degree circle. Mars is about 155 million miles away now with a 5″ disk so none of our scopes should be able to see any detail on the red planet.

~Jupiter, (Mag -2.0) will set about 3:25 pm in constellation Taurus Saturday evening before the Sun sets, so will not be seen at our star party. It rises at 1:25 am so can be seen in the early morning. It now is about 501 million miles from Earth getting a little closer every day.

~Saturn, (Mag 1.1) will be in constellation Virgo this Saturday just 5 degrees from bright star Spica and planet Mars, and since it rises about 11:30 am, will be visible just after sunset high in the sky.  Saturn is about 937 million miles away slowly moving farther from Earth. Saturn’s globe measures 16″ but the rings span 37″ and tilt 14 degrees to our line of sight this month. As it gets dark, largest moon Titan (magnitude 8), which revolves around Saturn every 16 days, will be far west of Saturn. Moon Enceladus will be seen just on top of Saturn followed by moon Rhea further east. Moon Tethys will be just under Saturn a bit west and moon Dione will also be under Saturn just a bit east under the rings.

~ Uranus, (Mag 5.8) will be in constellation Cetus this Saturday evening but doesn’t rise until just after 10 pm so can be seen at the BSC star party. It shows up as a small 3.6″ blue-green disc in a telescope. It is about 1.808 billion miles away from Earth.

~ Neptune, (Mag 7.8) is in constellation Aquarius, about 2.700 billion miles away this week slowly moving closer to Earth. It is seen as a bluish gray 2.4″ disc in a telescope. We should be able to see it at BSC this Saturday evening, as it rises about 8:30 pm.

 ~ Pluto, (Mag 14.0) rises about 5 pm so might be seen Saturday evening.  It is 2.927 billion miles from Earth in constellation Sagittarius. Since it is so dim, you will probably need a 10″ or larger telescope to see it visually. The June 2012 Sky & Telescope magazine shows Pluto’s path for all of 2012 on pages 52-53.  On Saturday, Pluto will be just a half degree from the center of M25.



The Perseid meteor shower reaches its peak Saturday night, when observers under dark skies might see 60-80 meteors an hour looking northeast after midnight. These meteors are tiny pieces of rock and dust from Comet 109P/Swift Tuttle. We normally see a few sporadic meteors at every Black Star Canyon star party.


Brightest visible Comets:

This month all the comets orbiting the Sun are very dim so will be extremely difficult to find and see. 


The magnitude 13.4 Comet C/2011 L4 Panstarrs can be seen Saturday at the BSC star party in constellation Libra (10 degrees in front of the Scorpion’s head). It is 700 million miles from the Sun at this time. This comet was discovered in June 2011 by a team using the Pan-Starrs telescope on Maui and has a very parabolic orbit. It will approach within 30 million miles of the Sun in early 2013, about the distance Mercury is from the Sun.




The magnitude 13.8 Comet 96P Machholz can be seen Saturday at the BSC star party in constellation Coma Berenices (between Arcturus and the tail of Leo the Lion). It is just 87 million miles from Earth at this time. This comet was discovered in May 1986 by Donald Machholz and has a period of 5.3 years. It approaches within 11.5 million miles of the Sun, the closest of any known periodic comet.


The magnitude 13.3 Comet C/2009 P1 Garradd is in the constellation Leo now so is too close to the Sun to be seen Saturday. The comet is 398 million miles from Earth traveling back into the depths of the solar system so is getting very dim.



Brightest visible asteroids:


Bright asteroids Ceres and Vesta are close to Jupiter this month so cannot be seen Saturday evening but can be seen in the early morning.


Minor Planet 2 Pallas (Mag 9.3) is in constellation Cetus this month just 5 degrees  north of Uranus. It is about 219 million miles from Earth and has an orbit period of 4.61 years.  This asteroid may be the largest irregular object in the solar system as it is not rounded under its own gravity. It was discovered in 1802 by astronomer Heinrich Olbers.


Minor Planet 18 Melpomene (Mag 9.5) is in constellation Ophiuchus this month about 15 degrees northwest of the “Teapot’s” lid so could be spotted at the star party. It is about 123 million miles from Earth at this time and has an orbit period of 3.48 years. It is potato shaped about 90 X 80 miles in diameter. This asteroid was discovered in 1852 by J. R. Hind from London.