07/25/09 Black Star Canyon star party

Posted On July 22, 2009

BSC – Saturday 25 July 2009

Hello Fellow OCA club members!

This Saturday I plan to open the gate at 7:30 pm, about a half hour before the sun sets. Today’s weather report for this Saturday indicates that the low at Black Star Canyon will be just under 70F. The New Moon was July 21st so we will have a 1st Quarter Moon that will set around 10 PM. 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. 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.


There will be one bright (Mag -2.5) visible (to the naked eye) evening pass of the ISS (International Space Station) at 9:06 PM starting at 10 degrees NNW rising to 40 degrees NE at 9:09 and dropping down to 28 degrees E at 9:10. For an even bigger challenge, the ISS Toolbag (Mag 5.9) will pass over this Saturday evening at 8:15 PM starting at 10 degrees WNW rising to 42 degrees SW at 8:18 and then dropping back down to 10 degrees SSE at 8:20. We will also get to see one Iriduim flare Saturday evening starting at 10:47 at 12 degrees high NE (51 degrees) from Iridium satellite 50 (Mag -6) . The HST (Hubble Space Telescope) will not be visible from Orange County this Saturday evening.


~Mercury (Mag -1.1) sets about 8:30 PM so might be seen this Saturday evening. It is 123 million miles from Earth in constellation Cancer heading towards Leo. Mercury can best be seen just before sunrise.

~Venus (Mag -3.9) rises about 3 AM, in constellation Taurus and is very bright and easily seen shortly before sunrise. It is 70% illuminated so looks like a half moon in a telescope and now is about 99 million miles from Earth. Venus will not be visible Saturday evening.

~Mars (Mag 1.1) is also in Constellation Taurus and now is about 168 million miles away. Mars sets about 4:15 PM so will not be seen this Saturday evening. It rises about 2 AM so can only be seen in the early morning sky. Venus will shine 100 times brighter.

~Jupiter (Mag -2.6) rises about 9:15 PM in constellation Capricornus so we finally have time to view the big planet again at BSC. It now is about 382 million miles away. Europa will be the lone moon to the east while moons Ganymede, Io & Callisto will be to the west of Jupiter in that order.

~Saturn, (Mag 1.1) sets about 10:30 PM just a few hours after the Sun sets Saturday. It is about 936 million miles getting further from Earth. It will be found below the hind end of Leo the Lion somewhat washed out in the glow of the sunset. The rings are tilted almost edge on so will be hard to see in July. The moons also orbit edge-on so are seen more in line now and are often seen in the rings. Brightest moon Titan will be very close to Saturn on the west this Saturday with Tethys, Enceladus and Dione a bit further from the planet. Only moon Rhea will be to the east of Saturn further from the planet than any other moon..

~ Uranus (Mag 5.8) will rise about 10:40 PM in constellation Pices this week so can be seen Saturday evening. It shows up as a blue-green disc in a telescope and is about 1.816 billion miles away inching closer to Earth.

~ Neptune (Mag 7.8) will be in constellation Capricornus about 2.708 billion miles away this week. It is seen as a bluish disc in a telescope and we should see it this Saturday as it rises about 9:15 PM. It will be within 2 degrees of Jupiter this month so both can be seen in the same field of view using a wide angle eyepiece.


The Delta Aquarids meteor shower peaks July 27/28 so we might see some activity Saturday evening up around Aquarius (near Jupiter). This meteor shower is attributed to the breakup of comets Marsden & Kracht.

Comet 22P Kopff (Mag 8.1) will be just a few degrees from the Ecliptic in Aquarius half way between Jupiter and Uranus. It is about 73 million miles away and has a period of 6.44 years.

Two other much dimmer Comets P/2009 F7 & P/2003 H4 (Mag 11.9) are in easternVirgo next to the Ecliptic. If you find one, you will see both in the same field of view this Saturday evening. They are about 119 million miles away and have a period of 6.1 years.

Minor Planet 1 Ceres (Mag 8.6), the very first asteroid ever discovered, is floating under Leo the Lion below the hind end. This is the last month we will see this asteroid before it slides behind the sun. This asteroid has a period of 4.6 years and is about 281 million miles away. It was discovered back in 1801 and is the largest asteroid we have found, having a diameter of 580 miles.

Another Minor Planet 16 Psyche (Mag 9.8) is along the Ecliptic just above Capricornus 10 degrees west of Jupiter this Saturday evening. This asteroid has a period of 4.99 years and is about 161 million miles away. It was discovered back in 1852 in Naples by Annibale de Gasparis and is 120 miles wide.

Deep Sky:

Lets look for some Antares Globulars this month in the Scorpion. They are fun to find in binoculars but using a telescope will bring out far more detail.

Globular cluster M4 (Mag 5.9), the Cat’s Eye, is just 1 degree west of bright star Antares in constellation Scorpius. It is now thought to be just 7,200 light years away and 107 light years in diameter. M4 has an estimated age of 10 billion years. Messier observed this object in 1764.

Globular cluster M80 (Mag 7.3) is midway between Antares and Beta Scorpii. It is estimated to be 33,000 light years away and 86 light years in diameter. The stars in this cluster are much more compacted than most globular clusters. Messier observed this object back in 1781.

Don’t forget to bring your gloves, coats & sweaters because you never know if it will get cold 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 it to get dark. Please remember to cart off all your trash as there are no garbage cans at BSC. Hope to see you there.
Your OCA star party host,