Saturday March 17th Black Star Canyon star party
By: Steve & Bonnie Short
March 14, 2012 2:49AM PDT
Views: 2956

BSC Star Party Notice  - Saturday March 17th, 2012


Hello Fellow OCA club members!


This Saturday, I plan to open the gate around 6:30 pm, which is about a half hour before the sun sets. The weather report for this Saturday indicates that Orange County will get rain Friday through Sunday. 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.


The last quarter Moon will start March 14th so 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 Irvine Ranch Conservancy property rule)



  The ISS (International Space Station) will not make any visible passes Saturday evening.

  The HST (Hubble Space Telescope) will make one magnitude 1.6 visible pass Saturday evening  starting at 8:08:30 pm 10 degrees high WSW rising to 40 degrees high at 8:12:29 S and then will drop to 27 degrees SE at 8:14:14 pm.

  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 2.0) sets at 8 pm but cannot be seen this Saturday evening as will be too low in the horizon and washed out by the Sun. It is about 65 million miles from Earth in constellation Pisces with a 6” diameter disk.

~Venus, (Mag -4.1) should be seen Saturday evening until it sets about 10:30pm in constellation Aries. It will be about 30 degrees above the horizon 1 hour after sunset. Venus is now about 75 million miles from Earth, is 57 % lit with a 21” disk.

 ~Mars, (Mag -1.1) is now in Constellation Leo rising about 5:45 pm. It is about 63 million miles away with over a 13” disk so small scopes might 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 under dark skies.

~Jupiter, (Mag -1.9) will not set until about 10:30 pm in constellation Aries so will be seen most of Saturday evening. It now is about 525 million miles from Earth getting a little farther every day. It has shrunk to a diameter of 35”. We should see moon Callisto far East of the big planet while moon Io will be much closer. Moon Europa, west of Jupiter will go into occultation behind Jupiter starting about 6:30 pm and exits east about 11 pm while largest moon Ganymede will be farthest west.

~Saturn, (Mag 0.7) will be in constellation Virgo this Saturday but won’t rise until 9:30 pm so we can expect to see it late at the star party.  Saturn is about 825 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 moons Dione, Enceladus and Tethys will be just east of Saturn. Moon Rhea will be the only moon west of Saturn’s rings.

~ 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 7:40 pm. It shows up as a small 3.4” blue-green disc in a telescope. It is about 1.958 billion miles away, moving further from 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.

~ Neptune, (Mag 8.0) is in constellation Aquarius, about 2.875 billion miles away this week slowly moving closer to 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 pm.

 ~ Pluto, (Mag 14.1) sets at 1 pm so cannot be seen Saturday evening.  It is 3.017 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 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. We normally see a few sporadic meteors at every Black Star Canyon star party.


Brightest visible Comets:

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 sometime in the next few months. It is now 121 million miles from Earth and can be found half way between the Little Dipper and Big Dipper pans. The 2011 November issue of Sky & Telescope Magazine shows the path this comet is following through February 6th on page 52.


The magnitude 11.2 Comet 21P Giacobini-Zinner is in constellation Cetus, so might be viewed this Saturday evening, although it is very dim. It is now about 180 million miles from Earth and has an orbital period of 6.60 years. It can be found just above the Whale’s head between Mercury and Jupiter.


Brightest visible asteroids:

Minor Planet 4 Vesta (Mag 8.2), the 2nd most massive object in the asteroid belt, can be found in constellation Cetus about 10 degrees above the Whale’s head. Vesta has a diameter of about 330 miles and was discovered in 1807. It is about 316 million miles from Earth at this time and has an orbit period of 3.63 years. It could 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 5 Astraea (Mag 9.1) is in constellation Leo this month about 10 degrees below the middle of the Lion’s tail. It is about 106 million miles from Earth at this time and has an orbit period of 4.13 years. It is another potato shaped rock about 75 miles wide. This asteroid was discovered in 1845 by amateur astronomer and postal employee Karl Ludwig Hencke and the King of Prussia awarded him an annual pension of 1,200 marks for the discovery. It should become visible shortly after sunset so might be seen at the BSC star party all the way up to midnight and later.


Minor Planet 1 Ceres (Mag 9.1) 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 back of the Whale’s head. It is about 348 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 for a short period of time (1.5 hours) 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 in Cancer the Crab:


M44 (Mag 3.1) is an open star cluster called the “Beehive Cluster”, 580 light years from Earth that spans 16 light years. It contains about 50 stars with the brightest shining at magnitude 6.3. The heart of the cluster contains a quartet of stars forming a box. Its age is estimated to be 660 million years and was first observed by Messier in 1769. It is found about half way between stars Regulus and Pollux.


M67 (Mag 6.9) is an open star cluster called the “King Cobra”, 2,700 light years from Earth. It spans 24 light years and contains about 200 stars, the brightest shining at magnitude 9.7. Its age is estimated to be 3.2 billion years and was observed by Messier in 1780. It can be found by moving the telescope slightly above the half way point between stars Regulus and Procyon. The majority of stars in this cluster form a semicircle with a single bright star lying just outside.


Iota Cancri is a double star consisting of a 4th magnitude and a 6th magnitude star that is separated by just 31”. This is the star on top (North) of the upside down “Y” shaped constellation.


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 you might bring, while waiting for the sky to get dark. Please remember to cart off all your trash as there are no garbage cans at BSC. There is also one portable restroom on site should nature call.


Hope to see you there.


Your OCA star party host,


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