Wednesday, August 10, 2016

sporadic observing

My observing has been a little light the last couple of weeks.  Some nights I chose to work on the 10-inch mounting, which is slowly making progress.  Other nights I was fooled by the marine layer -- I would see it on my drive home from work and it would seem to be blowing in, so I would not bother to set up.  But after dark I'd look out the window and see clear sky.  Other nights I would set-up the 12-inch but just enjoy some simple gazing at Mars, Saturn, or some random doubles -- not much to relate.

Last night I worked on the mount until dark and then observed for about an hour and a half with the 8-inch.  Seeing was very good.  The first quarter moon looked great, very contrasty and interesting, at 184x to start then 368x.  Mars was noticeably gibbous and getting smaller.  Saturn was really nice, with Cassini Division very steady and even the Encke Minima seen.  The shadow Saturn casts on the rings seems to be getting larger.  I could see some red/orange in the equatorial and polar regions, mixed with the sickly green.

The find of last night was Ross 154 (aka V1216 Sag), a young < 1 billion year old hydrogen burning flare star in Sagittarius.  There were not enough stars to accurately star hop using the 50mm finder given the light pollution and haze near the horizon, so I positioned the reflex sight to the approximate location based on AAVSO finder charts.  Located after some sweeping with a low power eyepiece, it had about the same magnitude as distinctive triangle of stars about half a degree to the SW.  Reddish color.  It fluctuates by 3-4 magnitudes every two days; a very remarkable object and worth monitoring throughout the season.  It is a red dwarf, 17% sol mass and 24% sol radius, about 9 ly away and moving towards the sun, closest approach at 6.29 ly 157k years from now.  I will try to get out again tonight to see if it has changed in relation to those marker stars.  Oddly, I can't find any observations on AAVSO, I would think this is a commonly monitored star.

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