Saturday April 11th Black Star Canyon star party
By: Steve & Bonnie Short
April 3, 2015 8:14PM PDT
Views: 2473


Black Star Canyon Star Party notice - Saturday April 11th, 2015


Hello Fellow OCA club members!


This Saturday, I plan to open the gate around 7 pm, which is about a half hour before the sun sets. The weather report for this Saturday indicates that Orange County should be warm, have clear skies and humidity near 25%.  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.


The 3rd quarter moon begins April 12th so the Moon will not be up during our star party. 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

The BSC star party site has a Latitude of 33.7520N, Longitude 117.6745W and Elevation 297'.


Warning:  No 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 not make any visible passes Saturday evening.

  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 -1.7) sets about 7:20 pm in constellation Pisces this Saturday so will not be seen at the BSC star party. Mercury will be about 125 million miles from Earth and rises about 6:30 am. It will pass behind the Sun April 9th and not reappear for 10 days.

~Venus, (Mag -3.9) can be seen about 3 hours after sunset Saturday evening as it sets about 10:20 pm in constellation Taurus. Venus will be about 106 million miles from Earth with a disc size of 15” and 75% lit. Look for it near the Pleiades star cluster.

~Mars, (Mag 1.5) will be in Constellation Aries about 20 degrees high an hour after sunset so might be seen at BSC this Saturday evening in the southwestern sky. It will be about 225 million miles away with a disk size of about 4.0”, about the size of a star so don't expect to see any detail on the red planet. Mars sets about 8:30 pm so better view it early.

~Jupiter, (Mag -2.1) will rise about 1:40 pm Saturday in constellation Cancer so can be seen high in the sky Saturday evening. It will be about 458 million miles from Earth getting a little farther every day with a diameter of about 40”. It can be seen most of the night as does not set until 3:25 am. At 8:30 pm we should see moon Callisto far to the East of Jupiter while moon Europa will be much closer to the planet followed by moons Ganymede and Io (all 4 moons will be on the East side).

~Saturn, (Mag 1.0) will be in constellation Scorpius this Saturday so might be seen late Saturday evening after it rises about 10:30 pm. It has a disk measuring 18” with rings spanning 41” and tilting 25 degrees. Saturn will be about 857 million miles away Saturday.

-----Both Uranus & Neptune are low in the morning sky so would be better viewed a few months from now.

 Uranus, (Mag 5.9) will be in constellation Pisces this Saturday evening setting about 6:50 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. Uranus will be about 1.953 billion miles from Earth this Saturday. It could be seen in the early morning sky when it rises at 6:20 am.

Neptune, (Mag 7.9) is in constellation Aquarius, about 2.855 billion miles away this week slowly moving closer to Earth. It is seen as a bluish gray 2.3” disc in a telescope but we will not see it at BSC this Saturday evening early as it set about 3:50 pm. It could be seen early morning as it rises about 4:40 am.

 Pluto, (Mag 14.1) sets about 11:40 am in constellation Sagittarius so will not be seen Saturday evening. It is about 3.045 billion miles from Earth, rises about 1:30 am and is so dim, you would need a 10” or larger telescope to see it visually.


The major meteor shower in April is the Lyrids from the 16 - 25th with a radiant near Vega where at the peak, one might see 18 meteors/hour. But we always see a few stray meteors during every BSC star party.

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, except for the one everybody is still talking about, Comet Lovejoy.

Comet C/2014 Q2 Lovejoy is a magnitude 6.0(according to the Heavens-above website) and will be 178 million miles from Earth Saturday in constellation Cassiopeia. It can be seen about 15 degrees above the weak “W” side of the constellation. The path it is taking in April is shown on page 42 of the April Astronomy Magazine.

This comet was discovered on August 17th, 2014 by amateur astronomer Terry Lovejoy from Brisbane, Australia, his 5th discovery. It looks to have a period of 14,234 years.

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 8.0), the 2nd most massive object in the asteroid belt. It would be found in constellation Aquarius this month, just below the Ecliptic. Vesta has a diameter of about 330 miles and was discovered in 1807. It is about 265 million miles from Earth at this time and has an orbit period of 3.63 years. It will not be visible Saturday evening as is an early morning object. NASA’s Dawn spacecraft was in orbit around this asteroid and sent back stunning close-up pictures.


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 Capricornus just 10 degrees below the Ecliptic and well in front of the Goat. It will be about 270 million miles from Earth Saturday 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 an early morning object. The Dawn spacecraft has just reached this asteroid and will be orbiting it taking pictures for at least a year.

Minor Planet 44 Nysa (Mag 9.7) is a small object in the asteroid belt with a diameter of about 44 miles. It will be in constellation Virgo above the Ecliptic about 10 degrees below the bright Leo tail star. Nysa will be about 123 million miles from Earth Saturday and has a period of 3.77 years. It was discovered in May, 1857 by German-French astronomer Hermann Goldschmidt and 4 years later he had discovered 14 asteroids, the record at that time. But don’t expect to see anything more than a small dot. It will be visible Saturday evening and the path it is taking in April is shown in the April Astronomy Magazine on page 43.

Deep Sky:

This month, lets consider looking at some galaxies in Virgo near M49 just behind Leo the Lion:

M49 is a magnitude 8.4 elliptical galaxy and one of the many Virgo Cluster Galaxies. It spans at least 147,000 light years and is 56,000,000 light years from Earth. Not easy to find but it is 8 degrees west of Virgo star Vindemiatrix by itself between two bright 6th magnitude stars that are about 1.5 degrees apart. Messier observed this object in 1779 and compared its brightness to a comet he was watching. But he first observed it in 1771 and logged it on February 19th.

NGC4526 is a magnitude 9.7 lenticular galaxy that is seen nearly edge-on. It is one of the brightest lenticular galaxies, which is defined as an intermediate galaxy between an elliptical and a spiral galaxy. It is 55,000,000 light years away and has a massive black hole in it's center. It was the first to have that mass estimated by an astronomical interferometer measuring the rotation of gas molecules around its center. It's mass is thought to be 450,000,000 times our Sun. You can find NGC4526 about one degree to the left of M49 and slightly lower, with two stars on either side.

NGC4535 is a magnitude 10.0 barred spiral galaxy that is seen 43 degrees face-on. It is 53,000,000 light years away and has two major spiral arms. In 1999, the Hubble telescope was used to observe Cepheid variable stars in this galaxy and the period-luminosity relationship confirmed its estimated distance, which is consistent with other Virgo cluster galaxies. You can find NGC4535 just a half degree above NGC4526.


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,


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