BSC Star Party Notice - Saturday 30th April 2011

 Hello Fellow OCA club members!

 This Saturday, I plan to open the gate about: 7:00 pm, which is a half hour before the sun sets. The weather report for this Saturday indicates that Orange County will be sunny and warm, so the April star party should happen. But keep an eye on the OCA website where I will post a notice on the home page should the star party be cancelled for any reason.

 This Saturday evening we will have a 3rd quarter moon that doesn't rise until well after midnight (about 4:30 am) so we will have fairly dark skies. 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 Nature Conservancy property rule)

 Satellites:

The ISS (International Space Station) will make a short Mag -0.6 visible pass starting at 9:36:44 pm 10 degrees high to the North, rising to 11 degrees North at 9:37:11 where it will slip out of view into the Earth's shadow. The ISS will continue making visible evening passes clear through next week. The HST (Hubble Space Telescope) will not make any visible passes this week, including Saturday.  There will be no visible Iridium flares Saturday evening but I am sure we will see a few dim satellites pass over as we are looking up in the sky.

Planets:

~Mercury, (Mag 1.3) sets about 5:37 pm well before the sun sets so cannot be seen this Saturday evening. However, this planet rises just after 5 am so could be seen 4 degrees to the lower left of Venus Saturday morning just before dawn. It has a diameter of 9" and is about a third lit. It is about 64 million miles from Earth in constellation Pisces.

~Venus, (Mag -3.8) will not be seen Saturday evening as it sets just after 5 pm but can be seen in the morning as it rises about 4:55 am in constellation Cetus. It will be very bright and about 87 percent illuminated with a 11.7" diameter. It is now about 132 million miles from Earth.

 ~Mars, (Mag 1.2) is now in Constellation Pisces setting just after 6 pm so cannot be seen this Saturday evening. It rises at 5:22 am and might be seen just above Jupiter.  It is about 216 million miles away, still too far away to see any detail on the planet anyway.

~Jupiter, (Mag -1.9) will set about 6:15 pm in constellation Pisces before the sun sets so will not be seen Saturday evening. It now is about 550 million miles from Earth getting a little closer every day. It can be seen 30 minutes before the sun rises very low (1 degree) above the horizon.

~Saturn, (Mag 0.5) rises about 5:23 pm Saturday in constellation Virgo so will be visible at the BSC star party. Saturn is about 809 million miles away slowly moving further from Earth. The ringed planet will not set until 5:15 am so can also be seen in the early morning sky this month. The rings are tipped to 9 degrees from edge on and span 44" along their main axis. Moon Enceladus will be just to the east of Saturn's rings while Titan will be much further east. Moons Tethys, Dione and Rhea will be to the west of Saturn, in that order at about 8:45 pm.

~ Uranus, (Mag 5.9) will set at around 4:45 pm this week in constellation Pisces so will not be seen Saturday evening. When seen, it shows up as a small blue-green disc in a telescope. Since Uranus will rise at 4:37 am, it might be seen in the morning but would be a challenge. It is about 1.945 billion miles away, moving closer to Earth.

~ Neptune, (Mag 7.9) is in constellation Aquarius, about 2.828 billion miles away this week slowly moving closer to Earth. It is seen as a bluish 2.2" disc in a telescope but we will not be able to see it at BSC this Saturday evening as it sets about 2:15 pm. However, it could be spotted about 10 degrees above the horizon before dawn as it rises at 3:10 am.

Meteors/Comets/Asteroids:

The April Lyrids meteor shower peaked on April 22nd, but was washed out by the moon. Under a dark rural sky, one might have seen 10 meteors per hour. We normally see a few stray meteors at every BSC star party even when no meteor shower is expected.

Comets: There are no visible comets brighter than magnitude 12 right now.

Brightest visible asteroids:

Minor Planet 4 Vesta (Mag 7.4), the 2nd most massive object in the asteroid belt, can be found in the top of constellation Capricornus along the ecliptic. Vesta has a diameter of about 330 miles and was discovered in 1807. It is about 184 million miles from Earth at this time and has an orbit period of 3.63 years. It won't be visible until about 1 am so will not be seen at the BSC star party.

Minor Planet 1 Ceres (Mag 9.4) is the biggest object in the asteroid belt with a diameter of about 590 miles. It is in constellation Aquarius below the Ecliptic. Ceres is about 322 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 not be visible Saturday evening until 3:30 am so will not be seen at the BSC star party.

Minor Planet 10 Hygiea (Mag 9.5) is the 4th largest object in the asteroid belt with an oblong diameter of about 220 -310 miles. It is in constellation Libra and can be found about 5 degrees directly in front of the Scorpion's 3 head stars. Hygiea is about 168 million miles from Earth and has a period of 5.58 years. It was Annibale Gasparis's first asteroid discovery made on April 12th, 1849. He lived in Naples, Italy and went on to discover 8 more asteroids.

  Deep Sky:

This month let's go galaxy hunting again near the Big Dipper along the bottom of the dipper pan. These will be the next to the last two objects Messier cataloged. Let's also look at the famous "Owl" planetary nebula between the two galaxies:

M108 (Mag 10.0) is a spiral galaxy found near the Ursa Major Beta star. It is about 24 million light years away and has a diameter of about 56,000 light years. We view this galaxy nearly face on, much like we view M81, so it has an oval shape. Messier observed it in 1781.

M109 (Mag 9.8) is another spiral galaxy found near the Ursa Major Gamma star. It is about 27 million light years away and has a diameter of about 63,000 light years. We view this galaxy edge on, much like we view M82, so it looks like a cigar. Messier observed it in 1781.

M97 (Mag 11) is a planetary nebula below the Big Dipper pan in between M108 & M109. It is somewhere between 1,200 - 12,000 light years away and has a diameter somewhere between 1.1 - 10 light years.  This is a very faint diffused, round object that is 2-3 times bigger than the Ring Nebula (M57). Messier observed it in 1781.

  Don't forget to bring your gloves, coats & sweaters because it will get even colder 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 darken. 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,

Steve