Saturday December 13th Black Star Canyon star party

Posted On December 9, 2014

Black Star Canyon Star Party notice - Saturday December 13th, 2014

Hello Fellow OCA club members!

This Saturday, I plan to open the gate around 4:15 pm, which is about a half hour before the sun sets. The weather report for this Saturday indicates that Orange County may have cloudy skies and humidity near 50%.  So please keep an eye on the OCA website "Home" page (below the next speaker info) where we will post a notice should the star party be canceled for any reason.

We should have dark skies as Sunday happens to be the 3rd Quarter Moon for December. 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 may 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.


Try to park two cars in each slanted slot between the rock turning circles so we can get 20 cars into that area. I will help guide the first cars into the slots and then expect that others will follow that pattern. The first car in each slot must stay back, about a foot, from the road that leads out of the parking area so cars that leave early with headlights off will not accidentally bump into parked cars.

WarningNo Pets allowed(This is an OC Parks and Nature Conservancy rule).


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

  The X-37B (Air Force Boeing space plane) will not make any visible passes as it has landed.

  The HST (Hubble Space Telescope) will make one magnitude 2.6 visible pass Saturday evening starting at 5:34:05 pm 10 degrees high SW going up to 22 degrees SSE at 5:37:21 pm and then dropping to 10 degrees ESE at 5:40:37 pm. A second magnitude 3.1 pass starting at 7:14:28 pm 10 degrees high WSW going up to 22 degrees high at 7:16:11 pm SW where it will drop out of sight.

  Iridium flares: There will be no visible Iridium Flares this Saturday evening but I am sure we will see a number of satellites pass over in the early evening.

Planets & Pluto:

~Mercury, (Mag -0.5) sets about 4:45 pm in constellation Ophiuchus this Saturday so won't be seen at the BSC star party. The small planet passed on the far side of the Sun the 8th of this month (superior conjunction) so won't be seen for 3 weeks. Mercury will be about 134 million miles from Earth and does not rise until after 7 am.

~Venus, (Mag -3.7) probably will not be seen Saturday evening as it sets about 5:30 pm in constellation Sagittarius. Venus will be about 155 million miles from Earth, and passed behind the Sun October 25th. On December 15th, Venus will appear only 3 degrees high a half hour after sunset.

~Mars, (Mag 1.1) will be in Constellation Capricornus about 20 degrees high a half hour after sunset so might be seen at BSC this Saturday evening in the southwestern sky. It will be about 176 million miles away with a disk size of about 5" (but don't expect to see any detail). Mars sets about 8 pm so better view it early.

~Jupiter, (Mag -2.1) will not rise until 9:30 pm Saturday in constellation Leo so will not be seen until late Saturday evening. It will be about 443 million miles from Earth getting a little closer every day with a diameter of about 39". It can be seen all night as does not set until 10:45 am. At 6:30 pm we should see moon Ganymede far to the East of Jupiter while moons Io,Europa and Callisto will be grouped together a couple of planet widths to the West.

~Saturn, (Mag 1.3) will be in constellation Libra this Saturday so will not be seen Saturday evening as it sets about 3:15 pm. It has a disk measuring 15" with rings spanning 35" and tilting 25 degrees. Saturn will be about 1.009 billion miles away Saturday. It does rise at 5 am so can be seen before sunrise.


Note: The 2014 paths of Uranus and Neptune are shown in the September Sky & Telescope magazine on page 51.

 ~ Uranus, (Mag 5.8) will be in constellation Pisces this Saturday evening rising about 1 pm so we should see it at the BSC star party when it gets dark. It shows up as a small 3.6" blue-green disc in a telescope so look for it when it gets dark. Uranus will be about 1.827 billion miles from Earth this Saturday and will not set until 1:15 am.

~ Neptune, (Mag 7.9) is in constellation Aquarius, about 2.813 billion miles away this week slowly moving farther from Earth. It is seen as a bluish gray 2.3" disc in a telescope and we might be able to see it at BSC this Saturday evening as it rises 11:15 am and does not set until 10:15 pm.

 ~ Pluto, (Mag 14.2) rises about 8:15 am in constellation Sagittarius so will be low in the sky Saturday evening as it sets about 6:15 pm. It is about 3.134 billion miles from Earth and since it is so dim, you would need a 10" or larger telescope to see it visually. The path Pluto was following in November can be seen in the November Astronomy magazine on page 36.



The Geminid meteor showers will be active from December 4-17 peaking on the 14th. You could expect to see up to 120 meteors per hour at its peak in dark skies. So we might see some of these meteors at the BSC star party late in the evening looking towards the radiant which is next to Castor in constellation Gemini.


If you ever wanted to do some real scientific meteor counting, the International Meteor Organization (IMO) always needs more observers. You will need to follow the IMO's standards so your counts will be meaningful. See for more information.


Brightest visible Comets:

All the comets in the sky are very dim again this month with one of the brightest, C/2013 A1 Sliding Spring which came within 81,000 miles from Mars October 19th.


Comet C/2013 A1 Sliding Spring is a 9th magnitude (according to the December Astronomy Magazine) and will be 230 million miles from Earth Saturday in constellation Ophiuchus. It can be seen about 20 degrees above the Ecliptic between Mars & Venus so is above Sagittarius & Scorpius. The path it is taking is shown on page 42 of the December Astronomy Magazine.


This comet was discovered on January 3rd, 2013 by Robert McNaught at Siding Spring Observatory in Australia using a 0.5 meter (20 inch) telescope. It looks to have a million year orbit and at first was thought to have a chance of colliding with Mars.


Brightest visible asteroids:

Finding an asteroid at the BSC star party is always very challenging as they are dim and are just small dots.


The brightest asteroid this month again is Minor Planet 4 Vesta (Mag 7.8), the 2nd most massive object in the asteroid belt. It can be found in constellation Sagittarius this month just above the Ecliptic and above Venus. Vesta has a diameter of about 330 miles and was discovered in 1807. It is about 290 million miles from Earth at this time and has an orbit period of 3.63 years. It might be visible at the BSC star party at sunset. NASA's Dawn spacecraft was in orbit around this asteroid and sent back stunning close-up pictures.

Minor Planet 1 Ceres (Mag 9.0) is the biggest object in the asteroid belt with a diameter of about 590 miles. It is in constellation Ophiuchus and will be just behind Mercury and the Sun on the Ecliptic. It is about 353 million miles from Earth now and has a period of 4.61 years. It was discovered in 1801 and for 50 years was classified as the 8th planet. But don't expect to see anything more than a small dot. It will not be visible Saturday evening as is too close to the Sun. This asteroid will be the next stop for the Dawn spacecraft in 2015.


Deep Sky:

This month let's consider looking at some Messier objects in the greater Andromeda area:


M31 is the famous magnitude 3.5 Andromeda Galaxy, a nearby spiral galaxy like our Milky Way. It is about 2.4 million light years away and spans at least 120,000 light years. It contains about 300 billion stars and is heading towards our galaxy at 60 MPS so should arrive in about 2 billion years. On a dark clear night this galaxy can be seen with the naked eye. It is found along the middle strands of the Andromeda constellation. This nebula was discovered in 1612 by Simon Marius and observed by Messier in 1764.


M33 is the famous magnitude 5.7 Pinwheel Galaxy, another nearby spiral galaxy like our Milky Way. It is about 2.2 million light years away and spans at least 40,000 light years. It is large and seen face on with faint arms. This galaxy is in constellation Triangulum and is found at least 10 degrees below M31. Look for it in a line from Mu & Beta Andromedae almost twice the distance from Beta as Beta is from Mu. This nebula was observed by Messier in 1764.


M34 is a magnitude 5.2 open star cluster about 1,400 light years away that spans 14 light years. You can find it in constellation Perseus as it forms the apex of a shallow isosceles triangle with Algol and gama Andromedae. It fills about the space of a Full Moon and contains at least 60 stars, some red in color, the brightest shines at a magnitude 7.3. Its age is estimated to be 190 million years. Messier discovered this object in 1764.


Don't forget to bring your gloves, coats & sweaters as it can get cold after the sun sets and even colder as 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,