seeing through the fog

Early this week the weather predicted clear skies, so I was excited to get a little observing done.  Astronomical twilight is not until after 9pm, and as these were work nights the sessions would be short.  I used the 8-inch to keep pace with my AL Carbon Star and Stellar Evolution lists, which are well suited for this scope.  However both nights were hampered by a thin marine layer blown in during the night.  The waxing moon's light was amplified and washed out much of the naked eye stars, so my star hops were much longer than usual.  On Monday night the moon resided in Virgo, for example, and the only star I could make out was Spica.  I could still star hop to Porimma, and even split it, but I could not find SS Virginis in the glare.  All the same, both nights were enjoyable.  Here are the observations, all at 113x / 0.9°:

Y Canum Venaticorum, carbon star, "La Superba": Orange in finder, bright pure orange in the scope.  By far the brightest in field, est. 5.0, C5 [AAVSO 5.3, C5].  One of the reddest stars in the sky, the brightest example of J-star, a carbon star with large amounts of carbon-13.  19th century astronomer Angelo Secchi gave it its common name.  It is likely in the final stages of fusing its remaining helium into carbon and shedding more material; it is ready to eject its outer layers to become a planetary nebula, with the remaining star to become a white dwarf.

RY Draconis, carbon star: Nice orange with a little yellow.  Brightest in field, est. 7.5, C4 [AAVSO 7.2, C4].  Uncertain period of around 200 days, 6.0-8.0 magnitude range

SAO 157721 (Virgo), carbon star: Very faint yellow orange star at the end of string of two other stars.  In glare of moonlight in thin marine layer.  Est. 9.0, C4.  [AAVSO N/A.  8.5, C2]

V Coronae Borealis, carbon star: Faint, small, faintly red in a rich field.  Est. 9.5-10.0, C5 [AAVSO 10.0, C6]  Long period variable, from 6.9 - 12.6 over 357 days.  To find this I used my 7x35 extra wide field binoculars and could fit all of this beautiful constellation in the field!

RR Herculis, carbon star: Small, faint, very red in arc of stars trailing NW to W.  Est. 8.0, C5 [AAVSO 8.5, C5-C8]

SAO 46574 (Hercules), carbon star: yellow-red, brightest in field, in a string of four stars W-E.  Est. 7.5-8.0, C2  [AAVSO N/A; 7.3 - 7.7, C3]

Beta Comae Berenices:  Long hop from Eta Virginis due to poor transparency and moon halo.  Very bright star, yellowish white color.  Main sequence dwarf star.  It is similar to our sun, slightly larger and brighter and only 3 billion years old. 

Spica / Alpha Virginis: Very bright, blue-white star.  It's a spectroscopic binary with orbital period of four DAYS!  Each star is distorted by the other. Both rotate faster than their orbital period, and the highly ellipsoidal orbit may mean this is a very young star system.  It is a polarimetric variable: protostellar material might be entrained between the two stars.

Arcturus / Alpha Bootis, Very bright, yellowish.  Brightest star in north celestial hemisphere.  An orange giant, has exhausted the hydrogen in its core and in active hydrogen shell burning phase.  Jean-Baptise Morin observed it during the day with a telescope, first time for that, in 1635.  A red giant star, 110x brighter than the sun, stronger in the infrared, while being only slightly larger than the sun.  It has a high proper motion of two arcseconds a year, and a possible planetary system. 

Theta Bootis: F-type star Pretty, orange yellow color, bright.  47 light years from earth, so the photons entering my eye are the same age I am!

HD 139341, Bootes: Double star, both type K Blue-white A, slightly yellow B double star.  4/3 the mass of the sun but 11x larger, but only 3 billion years old.  A planet discovered in 2009.

14 Herculis: Yellow-white, ordinary looking.  It is an orange dwarf, 90% the mass, 70% the radius, and 36% the luminosity of the sun, but with 2x the metal content.  Two planets have been discovered to orbit it.

SS Virginis, carbon star: SS Vir was blocked by moon two nights ago, now out of the way; but still a long hop from Spica due to moon halo in marine layer.  SS Vir is a faint orange in the finder and intense orange in the scope.  Est. 7.0, C6.  [AAVSO 6.8, C6].  It is a carbon Mira variable, hydrogen alpha emission increases as it grows brighter in its 361 day period.  radius is 500 sol.

T Draconis, carbon star: Moved scope to other end of yard to clear roof.  Orange red and rather faint, rich field, Est. 8.0-8.5, C7.  [AAVSO 10.0, C6-8].

Wednesday night I had a look at Jupiter.  At the start of my session the Great Red Spot was dead center on the band.  Before going inside two hours later, the Spot had moved so its further edge was just touching the limb, and it was greatly foreshortened.  Very cool to see the change.

Both nights I spent some time looking at the moon's terminator at high magnification.  Really good contrast despite the conditions.  One of these days, I'll learn the names of all these features.