Saturday Jan 2nd Black Star Canyon star party
By: Steve & Bonnie Short
December 27, 2015 10:13PM PDT
Views: 1839

Black Star Canyon Star Party notice - Saturday January 2nd, 2016
Hello Fellow OCA club members!
This Saturday, we plan to open the gate around 4:15 pm, which is about a half hour before the sun sets. The weather report for this Saturday indicates that Black Star Canyon should get cold fast, but have fairly clear skies and humidity near 20% inland.  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.
With a 3rd quarter Moon rising after midnight, our star party should have a dark night sky. 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. Or just park along Black Star Canyon Road and walk down to the star party site.

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 at BSC.
  The HST (Hubble Space Telescope) will make two visible passes Saturday evening. The first magnitude 1.9 pass starts at 5:54:11 pm 10 degrees high WSW going to 38 degrees high S at 5:58:05 pm and then falling to 12 degrees high ESE at 6:01:32 pm. The second magnitude 305 pass starts at 7:35:41 pm 10 degrees high WSW going to 16 degrees high SW at 7:36:57 pm where it will fade out of sight.
  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 -0.1) sets about 6:15 pm in constellation Capricornus this Saturday evening so might be seen at the BSC star party but it will be low in the SW sky. Mercury will be about 80 million miles from Earth and does not rise until 8 am so would not be seen in the morning sky. Mercury reached superior conjunction with the Sun November 17th.
~Venus, (Mag -3.9) will set at 2:20 pm in constellation Scorpius so won't be seen this Saturday evening. Venus will be about 110 million miles from Earth with a disc size of 14” and about 80% lit. Look for it just before dawn when it rises about 4 am in the SE sky.
~Mars, (Mag 1.2) will be in Constellation Virgo setting about 12:30 pm so will not be seen Saturday evening. It might be seen to the left of the crescent Moon near dawn as it rises about 1:20 am. It will be about 155 million miles from Earth Saturday evening. Mars will have a diameter of 5.6” growing to 6.8” at the end of the month while brightening by half a magnitude.
~Jupiter, (Mag -2.0) might be seen Saturday evening after it rises about 10:30 pm in constellation Leo. It will be about 470 million miles from Earth getting a little closer every day. Jupiter will have a disk size of 39”. It will be visible all night after rising as does not set until 10:50 am. At 10:30 pm, largest moon Ganymede will be far to the east of Jupiter followed by Europa a few planet widths closer and then Callisto will be next to the big planet. To the west will be moon Io.
~Saturn, (Mag 1.4) will be in constellation Ophiuchus this Saturday setting about 2:45 pm so will not be seen this Saturday evening. It rises at 4:40 am so might be seen at dawn in the SE. Saturn will be about 1.009 billion miles away Saturday evening .
---The 2015 September Sky & Tel magazine shows the paths Uranus & Neptune are taking on pg 49.--
 ~ Uranus, (Mag 5.8) will be in constellation Pisces this Saturday evening rising about noon so should be seen at the BSC star party. It shows up as a small 3.5” blue-green disc in a telescope. Uranus will be about 1.850 billion miles from Earth this Saturday. It can be seen all evening as does not set until 20 minutes after midnight.
~ Neptune, (Mag 7.9) is in constellation Aquarius, about 2.838 billion miles away this week. It is seen as a bluish gray 2.2” disc in a telescope and might be seen at BSC this Saturday evening as it rises at 10 am. It can be seen much of Saturday evening as does not set until about 9:15 pm.
 ~ Pluto, (Mag 14.2) will set in constellation Sagittarius about 5 pm so will not be seen Saturday evening low in the sky after sunset It is about 3.162 billion miles from Earth and is so dim, you would need a 12” or larger telescope to see it visually. Pluto does not rise until 7 am so cannot be seen in the morning either. The New Horizons probe reached Pluto July 14th and the path Pluto & the probe were taking through December is shown in the July Sky & Telescope Magazine on pages 52-53.

The Quadrantid meteor shower is active between December 28 – January 12 peaking January 4th. This year we can expect to see 120 meteors/hour at peak in dark skies. The radiant for this shower is in northern Bootes below the Big Dipper's handle. This meteor shower may be from debris from comet C/1490 Y1 observed 500 years ago. I am sure we will also see a few stray meteors Saturday evening as we always do at 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:
There are several dim comets in the sky this month, but the best one that will be visible Saturday evening might be Comet Catalina or Comet C/2014 Panstarr.

Comet C/2014 Catalina is shining at a magnitude 6.5 (according to the Heavens-above website) and will be 80 million miles from Earth Saturday in constellation Bootes just a few degrees above Arcturus. This comet was discovered on 31 October 2013 by the Catalina Sky Survey when at an apparent magnitude of 19 using a 0.68 meter (27”) Schmidt-Cassegrain telescope. This comet came from the Oort cloud and looks like it is on an ejection trajectory never to come back. See page 42 of the January Astronomy Magazine for the path Catalina is following.

Comet C/2014 S2 Panstarrs is shining at a magnitude 9.5 (according to the Heavens-above website) and will be 178 million miles from Earth Saturday in constellation Draco just 10 degrees below the Little Dipper's pan. This comet was discovered on 22 September 2014 by the Pan-Starrs 1 telescope (Haleakala). The latest calculations show a period of 2,210 years.

Brightest visible asteroids:
Finding an asteroid is always very challenging as they are dim and are just small dots.

Minor Planet 4 Vesta (Mag 8.0), the 2nd most massive object in the asteroid belt is the brightest asteroid again this month. It is still found in constellation Cetus this month, just above the Whale's nose. Vesta has a diameter of about 330 miles and was discovered in 1807. It is about 223 million miles from Earth at this time and has an orbit period of 3.63 years. It might be seen Saturday evening in the South. NASA’s Dawn spacecraft was in orbit around this asteroid and sent back stunning close-up pictures.
Minor Planet 1 Ceres (Mag 9.3) 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 star Deneb Algedi. Ceres will be about 345 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 be visible Saturday evening starting after sunset. The Dawn spacecraft has reached this asteroid and will be orbiting it taking pictures for at least a year.

Asteroid 15 Eunomia (Mag 9.4) is the largest of the stony (S-type) asteroids and somewhere between the 8th - 12th largest main-belt asteroid. It is estimated to contain 1% of the mass of the asteroid belt and will be in constellation Pisces Saturday evening so visible all evening long. This asteroid has a diameter of about 162 miles and is about 175 million miles from Earth. Eunomia was discovered by Annibale de Gasparis on July 29, 1851. It has an orbit period of 4.30 years and is 5 degrees to the left of the great “Square” near the bottom left side so might be seen at the BSC star party.

Deep Sky:
This month let’s consider looking at some neat multiple star systems:

y Andromedae is an attractive double star consisting of a bright orange star with a mag 5 blue companion. All that is needed is a 3” or larger scope to split these stars that are separated by 9.8” (arc-seconds). The stars called Almach AB are the third star in the first Andromeda strand starting from Alpheratz. This double is 355 light years from Earth and the stars are 1,065 AU distance apart with a rotation period of 61.1 years. The secondary is itself a double, both blue in color and separated by just .4”. The stars are each 1,179, 56 & 27 times brighter than our sun.

y Arietis is a pair of magnitude 4.8 bluish-white stars that appear to form a true system separated by 7.8”, although the relative motion of the stars is very small. Very little change has been noted in the last 350 years. The stars are 36 times brighter than our sun. There is a third component of this set of stars that is not gravitationally bound to the AB components. It is much fainter at magnitude 9.6 and is separated by 221”. This star system is found just a few degrees west of Aries Beta star.

n Cassiopeiae is a gorgeous double star consisting of contrasting colors. The colors are most often seen as gold and purple or yellow and red. The primary star is magnitude 3.4 while the secondary is a magnitude 7.5 M class dwarf. The two stars orbit each other every 480 years. The stars are just 19 light years from Earth and are 76 AU distance apart. This double star is found about half way between alpha star Shedir and the Gamma star in Cassiopeia. These stars form the inside of the big “V”.

I have given you the double star separations in arc seconds (“) but you can use an astrometric eyepiece to check the separation distance yourself. These eyepieces have a laser etched reticle with a ruler graduated at 100 micron intervals that can be used to measure distance. They have a battery powered variable illuminated system so the ruler scale can be easily seen.

Before an accurate measurement can be made, you must calibrate the linear scale to determine the number of arc seconds per division. This is done by using a stop watch to time how long it takes for a star to pass from one end of the scale to the other. To convert to arc-seconds, multiply the time by 15.0411 Cos Y, where Y = the star's declination. Then divide by the number of divisions in the scale.
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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