Saturday February 25th Black Star Canyon star party

Posted On February 22, 2012

BSC Star Party Notice  Saturday February 25th, 2012


Hello Fellow OCA club members!


This Saturday, I plan to open the gate around 5:15 pm, which is about a half hour before the sun sets. The weather report for this Saturday indicates that Orange County will be sunny, clear and warm. 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.


The new Moon will be February 21st so we should still 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.

  The HST (Hubble Space Telescope) will not make any visible passes Saturday evening 

  We will not see any Iridium flares Saturday evening 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 -1.2) sets at 6:30 pm so can be seen this Saturday evening. It is about 116 million miles from Earth in constellation Aquarius with a 6″ diameter disk.

~Venus, (Mag -4.0) should be seen Saturday evening as it does not set until about 9 pm in constellation Pisces. The small crescent Moon will be just 3 degrees above Venus. It will be about 20 degrees above the horizon 1 hour after sunset. Venus is now about 90 million miles from Earth, is 65% lit with a 17″ disk.

 ~Mars, (Mag -1.0) is now in Constellation Leo rising about 6:45 pm. It is about 65 million miles away with over a 13″ disk so small scopes can now clearly see some detail on the red planet. The white north polar cap tips towards Earth now and you should see some dusky markings on the planet’s surface.

~Jupiter, (Mag -2.0) will not set until about 10:30 pm in constellation Aries so will be seen most of Saturday evening. It now is about 497 million miles from Earth getting a little farther every day. It will outshine any other point of light in the sky, after Venus sets, and now has shrunk to a diameter of 37″. We should see moon Callisto far East of the big planet while moon Europa will be half as close. Moon Io will be to the west of Jupiter (and goes into occultation behind Jupiter starting about midnight) while largest moon Ganymede will be farthest west.

~Saturn, (Mag 0.8) will be in constellation Virgo this Saturday but won’t rise until 10 pm so we can expect to see it late at the star party.  Saturn is about 850 million miles away slowly moving closer to Earth. Saturn’s globe measures 18″ and the rings span 36″ and tilt 15 degrees to our line of sight. That is a healthy tilt so will provide observers with a good look at the dark Cassini Division that separates the two brightest rings. Largest moon Titan will be far East of Saturn while moon Rhea will be above (North) and just east of Saturn well above the rings. Moon Tethys will be just above the top of Saturn. Moon Enceladus will be just west of Saturn’s rings. Moon Dione will be below Saturn just a bit east.

~ Uranus, (Mag 5.9) will be visible as the sun sets this week in constellation Pisces so can be seen Saturday evening at BSC until it sets about 10 pm. It shows up as a small 3.4″ blue-green disc in a telescope. It is about 1.946 billion miles away, moving closer to 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 about 15 degrees south. You will find this distant planet below and to the right of Venus.

~ Neptune, (Mag 8.0) is in constellation Aquarius, about 2.882 billion miles away this week slowly moving farther from Earth. It is seen as a bluish gray 2.2″ disc in a telescope and we will not be able to see it at BSC this Saturday evening, as it sets about 5:30 pm.

 ~ Pluto, (Mag 14.1) sets at 1:30 pm so cannot be seen Saturday evening.  It is 3.047 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 when it rises about 3:20 am.  The 2011 July issue of Sky & Telescope Magazine shows the path Pluto was following in 2011 on page 64. From that diagram, one can see that Pluto is still found high above the Sagittarius “Teapot”.



February and March have no major Meteor showers so we will have to make due with the few sporadic ones we might see, especially in the last few hours just before dawn. One could expect to see maybe 6 per hour, especially the last week in February when there is no Moon in the sky. We normally see a few sporadic meteors at every Black Star Canyon star party.



The magnitude 7.0 Comet C/2009 P1 Garradd is in the southern section of constellation Draco so can be viewed this Saturday evening at sunset. The comet is still heading north and if it brightens as expected, it will become visible to the naked eye in early 2012. It is now 122 million miles from Earth and can be found half way between Polaris and the constellation Hercules. The 2011 November issue of Sky & Telescope Magazine shows the path this comet is following through February 6th on page 52.


The magnitude 8.7 Comet P/2011 Y1 Levy is in constellation Lepus, so might be viewed this Saturday evening. It is now just 32 million miles from Earth and has an orbital period of 5.29 years. It is heading east right into the middle of the Canis Major constellation. It can be found by following a straight line from the eastern most Orion belt star through star Saiph south about 14 degrees.


Brightest visible asteroids:

Minor Planet 4 Vesta (Mag 8.2), the 2nd most massive object in the asteroid belt, can be found in constellation Pisces about 6 degrees directly below Uranus. Vesta has a diameter of about 330 miles and was discovered in 1807. It is about 306 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. NASA’s Dawn spacecraft is in orbit around this asteroid and has been sending back stunning close-up pictures.


Minor Planet 433 Eros (Mag 8.9) is a shoe  shaped 21 mile long rock close enough to Earth this month that it is the 2nd brightest asteroid we can see. It is passing through Hydra, sliding along between Crater and Pyxis at over 12,000 mph. It is only about 20 million miles from Earth at this time and has an orbit period of 1.76 years. This asteroid was discovered in 1898 and was the first asteroid to be orbited by a probe back in 2000. It should become visible shortly after sunset so might be seen at the BSC star party all the way up to midnight and later. The path of Eros from January 15th through March 15th is shown in the February 2012 Astronomy Magazine.


Minor Planet 1 Ceres (Mag 9.2) is the biggest object in the asteroid belt with a diameter of about 590 miles. It is in constellation Cetus and can be found about 8 degrees above the Whale’s head. It is about 335 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 objects to the east of Canis Major in constellation Puppis:


M47 (Mag 4.4) is an open star cluster 1,800 light years from Earth that spans 16 light years. It contains about 30 stars with the brightest shining at magnitude 5.7. Its age is estimated to be 78 million years and was first observed by Messier in 1771. It is found by following a line starting from Beta Canis Major through Sirius and traveling about twice that far to the star cluster.  Three bright stars dominate the cluster with one being a double star.