night of two comets

I had the itch to go to a dark site this new moon, and this past Sunday presented an opportunity.  I went up to Fremont Peak, feeling the higher elevation would make up for the very slight 0.2 MPAS difference in sky darkness from my usual site.  I had the place to myself; I don't think there were even any campers.  There were low clouds along the southern horizon, so I kept to higher targets.  Seeing was very good.

I struggled as to which scope to bring.  I decided on the Ayers 4-/8-inch combo refractor, since it has been many months since I brought it out, and I had cleaned and collimated it a couple weeks ago.  It performed nicely, which I noticed right away when aligning my Telrad on the communications tower's warning lamps -- I could clearly see every detail.  

There were two comets up in the sky, which I observed as soon as it was dark enough.  

The first was C/2025 A6 Lemmon, a bright magnitude 2.78 with a 13.3' diameter coma and only 0.6 AU.  It was a few degrees SW of Rho Boötes, and I swept it up in my 8x42 birding binoculars before panning to it with the 4-inch visually, then conveniently switched to the 8-inch visually by flipping the folding mirror up.  Lemmon had a small, very intensely bright coma immediately around the nucleus, and the coma was rounded some distance in front (with a bright bow-shock arc).  The dust tail was bifurcated and rather stumpy, distinctly mottled inside.  I also looked at it with 3x night vision, and it was very striking in the field with a fat, stumpy tail, with a star in the center of the tail.  In the 8-inch with night vision, the tail was much lengthened and with two bright streaks in addition to the mottling.  I could detect subtle movement in the comet from when I had observed it 20 minutes prior visually.  This image is brighter and more detailed than what I saw, but conveys the impression:

The second comet was C/2025 R2 SWAN.  This was fainter, magnitude 7.00, with a 10.3' diameter coma with only a 0.3 AU distance.  It was more difficult to find since it had slipped east of the main Milky Way in Scutum.  I eventually swept it with my binoculars as a largish hazy glow, and then needed to sweep in the area with the 4-inch with night vision to find it.  It was smaller, with a fairly bright coma and a stumpy thick tail.  It's too bad I wasn't out a couple nights ago when this comet flew past M16.

I proceeded to observe with night vision in place.  I observed a few items from Steve's Deep Map 600 before realizing it is more suited to a telescope with greater image scale.  The 4-/8- combo is best suited to larger fields.  So, I searched my atlas for larger nebula.  I won't relate every observation, many of which I've seen before.  Just a few were more interesting:

Sh2-176: 00 31 38.3 +57 17 09, 10' diameter.  Planetary nebula. 

Very faint, round, mottled, with broken sides.  8-inch Ha.  

Sh2-170:  00 01 42.0 +64 37 24, 20' diameter

Irregularly round, mottled inside, it's the gas cloud around the unremarkable open cluster Stock 18.

NGC 6946: Fireworks Galaxy, a face-on spiral appeared small, faint, overall oval with a small bright nucleus and hints of spiral mottling inside.  Near open cluster NGC 6939, bright, dense, fan shaped.  Both in a dense field.

NGC 7380 / Sh2-142 "Wizard Nebula" but I described it as "fish-head shaped" diffuse nebula with a small dark pillar, associated with rich open cluster NGC 7380.   8-inch Ha

IC 342: face on spiral, best seen unfiltered with gain set to low, very faint halo was a contrast change with the background sky which nevertheless intimated spiral form, with a moderately brighter central mottled cloudiness with stars like a small open cluster. 

NGC 1499 California nebula.  Appeared positively solid, like part of a thundercloud, with darker and lighter streams and puffs, the central part is thick and heavily mottled with dark blotches.  4- and 8- inch, Ha.

NGC 752, a favorite open cluster, which I vividly remember observing for the first time from CalStar in 2015? with my old 12.5-inch f/7 dob, remembering the richness of the stars with the bright nearby red stars, and fainter red stars in the cluster.  Large and loose, with a good range of star brightness, it seemed less dense than I remembered (difference in aperture), but still wonderful.  8-inch, visually.

Toward the end of the night, I observed with night vision 1x with Ha, and what struck me was the cape of faint nebulosity off Perseus' shoulder, Mel 20 and east.  There are some small brighter knots to it (NGC 1491 is one), but it is really an unnoticed flow of nebula.  I can't find a good image of it, even in Finkbeiner's survey.   Worth further exploration.

Woke at 5am to try to beat traffic and be home to drive the kids to school (there was still some traffic in Morgan Hill).  I drove down to the bathroom building having left my eyepiece and clothes bag on the roof of my car!  Luckily I noticed before driving down the hill.