Saturday June 23rd Black Star Canyon star party

Posted On June 20, 2012

BSC Star Party Notice  Saturday June 23rd, 2012


Hello Fellow OCA club members!


This Saturday, I plan to open the gate around 7:30 pm, which is about a half hour before the sun sets. The weather report for this Saturday indicates that Orange County will be sunny but partly cloudy Saturday. So 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.


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 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 OC Parks and Nature Conservancy rule).



  The ISS (International Space Station) will make one magnitude -.07 visible pass Saturday evening starting at 10:01:44 pm 10 degrees high NW going to 54 degrees high NNE at 10:04:45 where it will drop out of sight in the Earth’s shadow.

  The HST (Hubble Space Telescope) will also make one magnitude 2.3 visible pass Saturday evening starting at 9:25:25 pm 10 degrees high WSW going to 23 degrees high SSW at 9:28:47 and then dropping to 20 degrees high S at 9:30:01.

  We will also get to see an Iridium flare Saturday evening at 10:08:10 pm up at 38 degrees altitude in the ENE (68 degrees) from Iridium satellite #98 that will be a bright -6.0 magnitude. I am sure we will also see a few dim satellites pass overhead as we are looking up in the sky.

Planets & Pluto:

~Mercury, (Mag -0.1) sets at 9:40 pm so can be seen early this Saturday evening. It is about 95 million miles from Earth in constellation Gemini with maybe a 7″ diameter disk. You might spot it 30 minutes after sunset just 6 degrees above the horizon.

~Venus, (Mag -4.3) will not be seen Saturday evening as it sets about 6:20 pm in constellation Taurus. The rare Venus transit occurred June 5th. Venus is now about 30 million miles from Earth and can only be seen just before dawn. On Saturday morning Venus should be 10% lit with a 50″ disk.

 ~Mars, (Mag  0.7) is still in Constellation Leo, just under the Lion, rising about a half hour after noon so is visible high in the sky as the sun sets until 45 minutes after midnight. It is about 125 million miles away now with a 7″ disk so small scopes should not see any detail on the red planet but the white North polar cap should still stand out.

~Jupiter, (Mag -1.8) will set about 6 pm in constellation Taurus Saturday evening as the Sun sets, so will not be seen at our star party. It rises at 4 am so can be seen in the early morning. It now is about 548 million miles from Earth getting a little closer every day.

~Saturn, (Mag 0.9) will be in constellation Virgo this Saturday just 10 degrees from bright star Spica, and since it rises about 3 pm, will be visible just before sunset.  Saturn is about 865 million miles away slowly moving farther from Earth. Saturn’s globe measures 28″ but the rings span 41″ and tilt 12.5 degrees to our line of sight this month. Largest moon Titan will be far west of Saturn with moons Rhea & Enceladus a bit closer and more in line with the rings. Moon Tethys will be just east and above the rings of Saturn with moon Dione much farther to the east.

~ Uranus, (Mag 5.9) will be in constellation Cetus this Saturday evening and sets about 1:30 pm so will not be seen at the BSC star party. It shows up as a small 3.4″ blue-green disc in a telescope if you want to catch it in the morning as it rises about 1:30 am. It is about 1.879 billion miles away from Earth.

~ Neptune, (Mag 7.9) is in constellation Aquarius, about 2.747 billion miles away this week slowly moving closer to Earth. It is seen as a bluish gray 2.2″ disc in a telescope. We will probably not be able to see it at BSC this Saturday evening, as it does not rise until 15 minutes before midnight.

 ~ Pluto, (Mag 14.0) does not rise until 10:30 pm so might be seen late Saturday evening.  It is 2.906 billion miles from Earth in constellation Sagittarius slowly getting closer to Earth. Since it is so dim, you will probably need a 10″ or larger telescope to see it visually.  It will be near 7th magnitude star SAO161635 this month. The 2012 June issue of Astronomy Magazine shows the path Pluto is following this month on page 43 while Sky & Telescope shows Pluto’s path for all of 2012.



The Bootid Aquarid meteor shower may peak before dawn June 27th if an outburst happens this year. The shower did occur back in 1998 and again in 2004 after decades of inactivity. The radiant will be in the northern part of Bootes, the herdsman. We normally see a few sporadic meteors at every Black Star Canyon star party.


Brightest visible Comets:

The magnitude 6.8 Comet 189 P Neat is in the constellation Telescopium under the Scorpion’s stinger. But it is so low on the SE horizon that we probably cannot see it at our latitude. It is only 22 million miles from Earth.


The magnitude 11.1 Comet C/2009 P1 Garradd is in the constellation Cancer so can be viewed this Saturday evening at sunset up until midnight. The comet is now in eastern Cancer near the border of Leo. It is 319 million miles from Earth traveling back into the depths of the solar system so is very dim. The June issue of Astronomy Magazine shows the path of this asteroid in June.



Brightest visible asteroids:


Asteroids Ceres and Vesta are too close to the Sun to be spotted this month.


Minor Planet 18 Melpomene (Mag 9.5) is in constellation Serpens this month about 10 degrees north of Sagittarius. It is about 125 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.



Deep Sky:

This month let’s consider looking at two globular clusters around bright star Arcturus:


M3 (Mag 6.2) in constellation Canes Venatici is one of the biggest and brightest globular clusters, 35,000 light years from Earth that is 165 light years in diameter. Contains about 50,000 stars and is estimated to be 6.5 billion years old. This object was first observed by Messier in 1764 and he described it as containing no stars having a brilliant center that gradually fades away. It can be found ¬Ω way between Arcturus and the bright Alpha corner star of Canes Venatici


M5 (Mag 5.7) in constellation Serpens (Caput) is another big and bright show-stopper globular cluster, 26,000 light years from Earth that is 132 light years in diameter. It is estimated to be 13 billion years old. This object was first observed by Messier in 1764 and he described it as containing no stars, big and round near bright 5th magnitude star Serpens. It can be found as the point that makes a right triangle using Arcturus and Spica




Don’t forget to bring your gloves, coats & sweaters because it can get very 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