Saturday 16 May 2009

Hello Fellow OCA club members!

This Saturday I plan to open the gate at 7:15 pm, about a half hour before the sun sets. Today’s weather report for this Saturday indicates it will be warm, sunny and clear. We will have a 3rd Quarter Moon Sunday which won’t rise until after we close at Midnight, so we should have a nice dark sky again for observing dim objects. 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 no visible evening passes of the ISS (International Space Station), the ISS Toolbag, or any Iridium Flares this Saturday evening. What a shame as the ISS has become bigger and very bright. Too bad we won’t be able to see the HST (Hubble Space Telescope) Saturday as it now is being serviced by a team sent up in the Space Shuttle.

Planets:

~Mercury (Mag 2.0) sets about 8:20 PM so must be spotted soon after sunset this Saturday evening. It is 54 million miles from Earth in constellation Taurus.

~Venus (Mag -4.4) rises about 3:50 AM, in constellation Pisces and is very bright and easily seen shortly before sunrise. It is 35% illuminated so looks like a crescent moon in a telescope and now is about 48 million miles from Earth. Venus will not be visible Saturday evening.

~Mars (Mag 1.2) is in Constellation Pisces and now is about 191 million miles away. Mars sets about 4:45 PM so will not be seen this Saturday evening. It rises about 4:10 AM and will be just 5 degrees to the left of Venus and a little below, Saturday morning.

~Jupiter (Mag -2.2) rises about 1:50 AM in constellation Capricornus and now is about 467 million miles away. It sets about 12:45 PM so we won’t see the big planet Saturday evening.

~Saturn, (Mag 0.8) rises about 2:10 PM so will be up high when the Sun sets Saturday. It is about 835 million miles from Earth and is about 6 degrees below the hind end of Leo the Lion. The rings are tilted about 4 degrees but will start narrowing in June. The moons also orbit edge-on so are seen more in line now and sometimes seen in the rings. Brightest moon Titan will be mid orbit to the west of Saturn on Saturday with Rhea near by, Tethys and Enceladus will be very close to the planet probably in the rings. Only Dione will be to the east of Saturn next to the rings.

~ Uranus (Mag 5.9) will set by 3 PM in constellation Pices this week so cannot be seen Saturday evening. It does rise at 3:15 AM so can be seen in the pre-dawn sky. It shows up as a blue-green disc in a telescope and is about 1.919 billion miles away.

~ Neptune (Mag 7.9) will be in constellation Capricornus about 2.798 billion miles away this week. It is seen as a bluish disc in a telescope but we will not see it this Saturday as it sets about 12:50 PM. Since it rises just before 2 AM, it can be seen the last few hours before dawn.

Meteors/Comets/Asteroids:

The Aquarid meteor shower peaked May 6th but one might see a few strays this month all the way up to May 28th if you look about 10 degrees to the left of Jupiter. These meteors are just small particles from Comet Halley smashing into Earth’s atmosphere at 150,000 MPH.

Comet C/2008 T2 Cardinal (Mag 8.4) will be deep in the Constellation Gemini this Saturday evening. We should find it far below Casper near that Twin’s right foot and is about 165 million miles from Earth. It will take at least an 8″ mirror to find this dim dirty snowball before it gets fainter and dives into the southern sky next month. It was discovered October 1st by University of Calgary researcher Robert Cardinal when it was just above Polaris.

Two other dimmer Comets P/2009 F7 & P/2003 H4 (Mag 11) are mid way between Corvus and Virgo. If you find one, you will see both in the same field of view this Saturday evening. They are about 76 million miles away and have a period of 6.1 years.

Minor Planet 1 Ceres (Mag 7.1), the very first asteroid ever discovered, is floating just over the middle of Leo the Lion-ììòs back. This asteroid has a period of 4.6 years and is about 202 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 14 Irene (Mag 9.2) is heading into Virgo and will be midway between Spica and Arcturus Saturday evening. This asteroid has a period of 4.16 years and is about 118 million miles away. It was discovered back in 1851 by English astronomer John Hind and is 112 miles wide.

Lets look for some double stars in Leo the Lion this month since it will be high in the sky with Ceres floating over it’s back and Saturn flying under it’s belly.

Bright star Regulus (Mag 1.35) is the 21st brightest star in the sky and about 77 light years away. It has a faint double sometimes visible even in binoculars. This star system is actually 4 stars, one a white dwarf that takes 40 days to orbit the bright A star and then dimmer B & C stars that are 4200 AU away taking 2,000 years to orbit each other which are about 100 AU apart. Regulus B is a small dwarf star and Regulus C is a dim red star.

The next brightest star in Leo is Algieba (Mag 1.98) up in the neck of the Lion. It is one of the best double stars in the sky with one looking orange/red and the other yellow/green. They are 126 light years away and orbit one another every 620 years. They are thought to be super giants at least 170 AU apart (4 times the distance between Pluto and Earth). One star is 23 times the diameter of the sun and the other about 10 times.

The final double star I want to address in Leo is Denebola (Mag 2.14) which is the tail of the Lion. It is a blue-orange pair that are an optical double meaning, they are not gravitationally connected but lie along the same line of sight. Denebola is a young star (about 400 million years old) and is about 36 light years away.

Don’t forget to bring your gloves, coats & sweaters because it may get fairly 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.
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Your OCA star party host,

Steve