Sunday, January 3, 2016

new year day's night, Lake Sonoma

I had been hoping to get out this weekend but checking the weather Friday morning found my usual sites in the South Bay would be clouded over by 8pm Friday night, and Saturday would be a total loss.  I was about to give up when I noticed Steve Gottlieb’s post on TAC about observing at Lake Sonoma.  The cloudiness would not reach there until midnight, leaving several solid hours of observing time.  Since it was New Year’s Day there was no traffic, and I could make the drive from Fremont in 2.5 hours; so I decided to come up.

This was my first visit to Lake Sonoma.  The site is pretty dark, SQML was ranging from 20.90 – 21.20.  This is lower than what is usually reported for the site; there may have been some water vapor in the air reflecting light from Santa Rosa.  The sky to the West is particularly dark and I spent most of my time there catching up on objects on my AL lists I missed in November and December.  We were able to observe until around 12:30am.  It was a very productive night.  Here are some of the more memorable observations, often objects I noticed on the chart while star hopping to my intended target [I made around 30 observations total but it will take some days to transcribe my notes.].  All in 20”:

NGC 1501, PN in Camelopardalis, “Camel’s Eye.”  At 205x without filter it was a grayish green round sphere with defined edges; central star visible with averted vision and some mottling in the center of the sphere.  OIII darkened the field and help bring out the mottling; the edges appeared softer.   At 333x without filter the central star was direct vision, there were more stars in the field, more definite mottling in the center and softer edges.  

NGC 896, EN in Cassiopeia: At 121x no filter it appeared a bean shaped glow.  UHC permitted better view; the nebula was brighter to the west but there was a thick arc starting from the south and looping east and north.  Open cluster Teu 55 just on the edge of the FOV (needed to move N896 out for best view) to the east was a faint mist of stars in an otherwise dark area of sky.

Jones 1, PN in Pegasus.  Very faint, larger than I thought it would be.  At 205x and seen only with the OIII, it looked like a C lock washer – “C” shaped with thicker / brighter tips, connected by a thinner band.  I had a tough time noticing it and only felt it was there by moving the scope around and seeing the dimness move with the stars.   (Thanks for the confirmation Carter & Steve!)

UGCA 441, “Barbon’s Galaxy” (Markarian 328, 23h37m39.5s +30d07m46s), in Pegasus.  I noticed this on the chart near Jones 1 and gave it a try.  I had to check my finder placement several times because when I looked in the eyepiece nothing was there.  Staring with averted vision, a small glow slowly emerged into view; it was like looking down at something white rising to the surface of a deep dark lake.  It had a brighter core and almost stellar nucleus, with a hint of halo, too faint to hold an elongation or tell a position angle.  NED shows this as 15.5 magnitude.  I find Roberto Barbon is an Italian astronomer, but not why the galaxy is named for him.  [After posting this report on TAC Steve replied with a link to Barbon's 1969 paper in which he measures spectra from several compact galaxies; this particular object was named for Barbon because it had previously been identified only as anonymous.  It is a blue compact galaxy, some 45 light years away.]

NGC 246, PN in Cetus, “Skull Nebula”.  OIII helped bring out significant mottling inside the pretty large and irregularly round nebula.  Central star easy along with three other stars involved which form a “V” open to the south.  Brighter arc on the WSW rim.

NGC 660, Gx in Pisces.  This was pretty bright with a slightly brighter elongated core, 4:1 SW-NE.  The DSS image shows it has dramatic “X” shaped dark lanes in the NE quadrant of the halo, and spiral arms trailing to the SE and NW, none of which I saw.  Definitely worth another look.

NGC 1535, PN in Eridanus, “Cleopatra’s Eye.”  Best view was 333x without filter.  Bright, blue, and round, it showed a bright inner and fainter but thicker outer ring structure; central star held with direct vision.  The inner ring was mottled and in moments of good seeing showed sharp curving lines of structure.

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