Saturday July 19th Black Star Canyon star party

Posted On July 16, 2014

Black Star Canyon Star Party notice - Saturday July 19th, 2014

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 should be partly cloudy, hot and 50% humidity.  But 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 fairly dark skies as the 3rd quarter Moon will not rise until well after midnight. 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.

Warning:  No Pets allowed!  (This is an OC Parks and Nature Conservancy rule).


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

  The X-37B (Air Force Boeing space plane) will not make any visible passes Saturday evening.

  The HST (Hubble Space Telescope) will make one magnitude 1.8 visible pass this Saturday evening starting at 9:50:38 pm 10 degrees high WSW going to 31 degrees high SSW at 9:53:31 where it will fade out of sight

 Iridium flares: There will be one magnitude -2.0 visible Iridium Flare this Saturday evening NE (54 degrees), 16 degrees high at 10:44:14 pm from Iridium satellite 40 seen near the Andromeda Galaxy.

I am sure we will also see a number of satellites pass over in the early evening.

Planets & Pluto:

~Mercury, (Mag -0.3) sets about 6:30 pm in constellation Gemini this Saturday so won't be seen at the BSC star party. Mercury will be about 96 million miles from Earth and can be seen just before dawn when it rises at 4:30 am.

~Venus, (Mag -3.7) will not be seen Saturday evening as it sets about 6:15 pm in constellation Gemini. Venus rises about 4 am so can be seen a few hours before sunrise. Venus will be about 140 million miles from Earth, dropping to about a 11" in diameter but will be almost fully lit.

~Mars, (Mag 0.3) is now in Constellation Virgo rising about 1 pm so can be seen at BSC this Saturday evening. It is now about 105 million miles away with a disk size of about 9 degrees and doesn't set until about midnight. So this is our last chance to get a final glimpse of some brown detail before Mars gets too far away.

~Jupiter, (Mag -1.6) will set about 8 pm Saturday in constellation Cancer so will be hard to spot as the Sun sets. It will be about 585 million miles from Earth getting a little further every day with a diameter of about 32".

~Saturn, (Mag 1.0) will be in constellation Libra this Saturday so can be seen Saturday evening as it rises about 2:30 pm. It has a disk measuring 18" with rings spanning 42" and tilting 21 degrees. Saturn can be seen all evening as it does not set until 1:20 am). It will be about 890 million miles away Saturday. Around 9 pm, we should be able to see some of Saturn's brightest moons starting with brightest moon Titan far west and above of Saturn with Rhea between Titan and Saturn. Moon Enceladus will be east and just under Saturn's rings while Tethys will be next to Enceladus (just to the east). Moon Dione will be a planet width to the east of Saturn's rings.

 ~ Uranus, (Mag 5.8) will be in constellation Pisces this Saturday evening setting about noon so we will not see it at the BSC star party. It shows up as a small 3.5" blue-green disc in a telescope so look for it late in the night as it rises 15 minutes before midnight. Uranus will be about 1.845 billion miles from Earth this Saturday.

~ Neptune, (Mag 7.8) is in constellation Aquarius, about 2.715 billion miles away this week slowly moving closer to 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 after it rises about 10 pm..

 ~ Pluto, (Mag 14.1) rises about 6:45 pm in constellation Sagittarius so might be seen Saturday evening as it does not set until about 5 am. It is about 2.950 billion miles from Earth and since it is so dim, you would need a 10" or larger telescope to see it visually. The July 2014 Astronomy Magazine shows the path Pluto is traveling in July.


The Southern Delta Aquariid meteor shower is active from July 12 - August 23 peaking July 30th. You can expect to see 15-20 meteors per hour at its peak with a radiant above Formalhaut in Aquarius.

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 the brightest, C/2012 K1 Panstarrs, a magnitude 11.8 in Leo according to the website, Heavens-above.

Page 42 of the July Astronomy Magazine shows the path comet Panstarrs C/2012 K1 is following early this month and predicts that it will be brushing the Lion's mane. But it will be difficult to find this object at the star party as is close to the Sun. It will be about 200 million miles from Earth.

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 July Astronomy Magazine, on page 42 shows the paths that Vesta and Ceres will be taking in July. Note that they will be less than 1 degree apart Saturday evening in constellation Virgo. But on July 1st, these asteroids were less than ¬Ω degree apart. The circular paths are between Spica and Arcturus, closer to Spica than Arcturus.

The brightest asteroid this month is Minor Planet 4 Vesta (Mag 7.3), the 2nd most massive object in the asteroid belt. It can be found in constellation Virgo this month in a direct line from Mars to Arcturus, 3 times closer to Mars than Arcturus. Vesta has a diameter of about 330 miles and was discovered in 1807. It is about 180 million miles from Earth at this time and has an orbit period of 3.63 years. It should 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 8.6) is the biggest object in the asteroid belt with a diameter of about 590 miles. It is in constellation Virgo and can be found just 1 degree behind Vesta (west) and about 10 degrees directly above Mars. It is about 236 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 be visible Saturday evening at sunset so might be seen at the BSC star party. This asteroid will be the next stop for the Dawn spacecraft.

Minor Planet 2 Pallas (Mag 9.4), is the second asteroid to have been discovered (after Ceres), and one of the largest in the Solar System. It can be found in constellation Leo this month about 1 degree below the end tail star, trailing Vesta & Ceres by about 30 degrees. This asteroid has a diameter of about 338 miles and is about 269 million miles from Earth. When Pallas was discovered by astronomer Heinrich Wilhelm Matthaus Olbers on March 28, 1802, it was counted as a planet, as were other asteroids in the early 19th century. The discovery of many more asteroids after 1845 eventually led to their re-classification. It is about 130 million miles from Earth at this time and has an orbit period of 4.62 years. It will become visible at sunset so might be seen at the BSC star party.

Deep Sky:

This month let's consider looking at 3 of the Fabulous Five globular clusters shown on page 47 of the July 2014 Sky & Telescope magazine:

M13 is the most famous, a magnitude 5.8 globular star cluster, known as the "Great Hercules Cluster". It is in constellation Hercules about 21,000 light years away and spans 104 light years. You can find it along two cornerstone stars, about 1/3 of the way down from the most northern, right-side corner star. Its age is estimated to be 14 billion years old and the estimated 500,000 stars have a tighter compactness than average. Messier observed this object in 1764 and logged it on June 1st.

M3 is a magnitude 6.2 globular star cluster in constellation Canes Venatici. It is about 35,000 light years away and spans 165 light years. You can find it about half way between bright star Arcturus and the bright "corner" star of Canes Venatici. The cluster contains about 50,000 stars and its compactness is considered average. Its age is estimated to be 6.5 billion years. Messier observed this object in 1764 and logged it May 3rd.

M5 is a magnitude 5.7 globular star cluster in constellation Serpens, about 26,000 light years away and spans 132 light years. It is slightly oval in shape and the compactness is tighter than average. There is a bright 5th magnitude star 5 Serpentis ¬Ω degree from the cluster. You can find it along a line from Arcturus to Antares, about 1/3 of the way to Antares. Its age is estimated to be 13 billion years. Messier observed this object in 1764 and logged it May 23rd.


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.