Hello Fellow OCA club members!
Sunset will be about 6:30 pm so I plan to open the gate about 6:00 pm so there will be plenty of daylight left for setting up telescopes. It is fall now so bring warm clothes to wear even though the day should be in the warm low 80's. Remember we close at midnight so it probably will get pretty cold (maybe 50F) by then.
A reason to come early might be to try and catch Mercury (Mag 0.0) just as the sun sets or maybe spot faint Comet C/2007 F1 (Mag 9.1) in Coma Berenices. This Comet will be just under Galaxy NGC 4278 (Mag 11) and by Oct 21st will be just under Arcturus (Mag 0.96). But the brightest object in the evening sky will be Jupiter (Mag -1.9) just behind the head of Scorpius with giant red star Antares (Mag 0.96) shining below. All of Jupiter's moons will be on the left side of the planet (but seen on the right side in my Maksutova telescope). Ganymede will be farthest out, then Callisto while Io & Europa will be seen almost clinging to each other.
Not far from Jupiter will be Dwarf planet Pluto (Mag 14) in Sagittarius but will require at least an 8" telescope, high power and dark sky to be seen. Neptune (Mag 7.9) will be easier to find in Capricornus as will Uranus (Mag 5.8) in Aquarius. Mars (Mag -0.1) will rise about 11:30 PM and may not be visible to us until midnight as it skims past open cluster M35 (Mag 5.1). Venus (Mag -4.7) & Saturn (Mag 0.8) will not be visible during the star party as they can only be seen near dawn right now.
Large asteroid 4Vesta (Mag 7.2) is now to the east of Jupiter right along the ecliptic while another 300 mile wide asteroid 2Pallas (Mag 9.0) sinks through Aquarius this month heading into southern skies. This was the second asteroid ever discovered back in 1802 right after 1Ceres was discovered in 1801.
We are in luck this Saturday evening as the ISS space station (Mag -0.1) will pass overhead at 7:10 pm 10 degrees to the west and get up to 23 degrees NW before slipping back down to 10 degrees NNE around 7:15 pm. A little later the HST Hubble Space Telescope (Mag 3.3) will pass over at 7:52 pm 10 degrees WSW rising to 25 degrees SSW and falling back to 20 degrees SSE at about 7:58 pm.
For deep sky objects this month I want to suggest two of the brighter globular star clusters, first discovered by Maraldi in 1746, which can even be seen under a bright city sky. That is why they are normally shown this time of the year at our OCA outreaches. M15 (Mag 6.4) observed by Messier in 1764 is 34,000 light years away and 122 light years in diameter consisting of about 30,000 stars. It can be found in the constellation Pegasus near star Enif (the horse's nose) on an arm opposite of the Andromeda. M2 (Mag 6.5) observed in 1760 is 40,000 light years away and appears slightly dimmer than M15. M2 is just 13 degrees south of M15 and forms a right triangle with the two brightest stars in the handle of Aquarius making it easy to find. About 150 such globular star clusters are scattered in a vast halo around our Milky Way Galaxy. They usually consist of several hundred thousand very old stars in a sphere.
Remember, Black Star Canyon is only 10 miles East of the 55 Newport Freeway measured from the Chapman Avenue East off ramp. It looks like we will have clear dark skies this Saturday so why not join us.
Your OCA star party host,