Tuesday, January 24, 2023

23 january 2023, 60mm

I finally had the opportunity to strap my "new old" Tasco 7TE-5 refractor to my 6-inch.  60mm with a 1000mm focal length, 1960s vintage.  After cleaning fungus off the objective and flocking, it gave some pretty sharp terrestrial views.  On the scope I only used very low power (just to align it with the 6-inch), but it was pretty sharp too.  There is some vignetting, probably from my flocking, which I will fix at some point.  It causes some balance problems on the mount, and I'm a little worried about it going out of alignment under the rain tarp, but these are all problems which can be resolved with time.

I made a few observations of Struve pairs.  Seeing was quite poor so I didn't stick with it for long.  It was also the first time using SkyTools with a new laptop, and I found some issues to fix too (screen brightness, screen settings, etc.).

STF 984 AB: 152; 200x: In poor seeing it apears mostly as an elongated smudge, hardening at the ends with seeing to a very close split.  WDS says not physical, and there is -74% parallax range overlap, it is not.
06h 56m 16.59s +32° 26' 41.4" P.A. 155.00 sep 3.3 mag 8.67,10.80 Sp G5

STF1054 AB: 152; 125x: 1 Dm, pretty wide, with a C pair in a similar PA a little further out.  WDS says parallax indicates physical, but the Gaia DR3 data shows -78% parallax range overlap, much too far to be binary.
07h 18m 05.48s +34° 57' 06.3" P.A. 292.00 sep 18.7 mag 8.16,9.96 Sp F2 dist. 139.08 pc (453.68 l.y.)

STF 983 AB: 152; 200x: B appears with averted vision only, 3 Dm, fairly wide.  It lies within a triangle of near equal magnitude stars.  WDS says it is not physical, and there is no parallax range overlap.
06h 56m 13.67s +34° 27' 32.7" P.A. 36.00 sep 10.7 mag 8.70,12.70 Sp B9

Sunday, January 22, 2023

pinnacles

After more than a month of rain, finally there was an open window to go out observing this new moon.  This Friday night was to be the clearest of several murky days, so I left in the early afternoon to beat traffic and headed to the Pinnacles.  When I arrived around 5pm, Pawan was nearly all set-up with his excellent 22-inch reflector.  I went for a walk to stretch my legs on the scenic overlook trail behind the visitor's station, and saw a deer and gazed at the yellow, orange, and dusky Pinnacles during the "golden hour."  It's my favorite thing about the park.  I noticed around a dozen condors circling the high peaks, all getting ready to settle down for the night.  Some of the High Peaks trails are closed due to nesting season.  Next time I will go and do a full hike up those trails.

There were around a dozen observers, too, who set up in the parking lot, some arriving after dark.  Some seemed to forget about the visitor center's motion detector lights, which flipped on several times (I set-up with my car as a light shield).  Generally, everyone was good about light control; the Astro photographer next to me even moved his scope when he noticed I was a visual observer, which was really nice.  But one guy slept in his car which was turned on all night long -- the engine noise was very annoying and made me feel I was at a truck stop.  It took away the silence.  

Pawan very kindly pulled up Mira at my request to let me hunt for JOY1.  I thought I noticed some little bump in the diffraction at the correct PA, but nothing I could claim.  Komal was there with his new refractor, and we looked at a couple double stars -- his scope gives about as perfect star images as I've ever seen, it's a really great scope.  Akarsh shared a view of Comet C/2022 E3 ZTF, which has a very bright fan-shaped dust trail sprouting from the bright coma.  I thought I saw the very thinnest ion tail, but it petered out very shortly after the dust tail.  

For my own observing I continued through the Sharpless catalog with the 4-/8-inch combo refractor and night vision.  The sky quality was not very good.  Seeing was poor early on, improving a little by 11pm.  SQML maxed out at 21.00 due to a blanket of upper-level water vapor.  It was cold too--less dew than I expected but there was frost on everything from about 12am on.  I was dressed warmly and didn't mind.  The observing was a little frustrating -- many objects next on the list were <3' and are really tough given the lack of image scale in my set-up.  And the larger objects were not very spectacular either.  I tried to mix in some showpiece objects, but the sky quality degraded the view, so it didn't help.  All with 67mm Plossl+, PVS-14; comments and images from Vogel's Sharpless Atlas.

Sh2-192/-193/-194: 02 47 13.3 +61 59 17: A trio of very small, very faint nebula, all <2' in diameter.  They were easy with the 4-inch and Ha since they are clustered together, so their combined glow helped make them more noticeable.  Best view with the 8-inch.  -194 is the largest and brightest, a fairly uniform round glow around a star.  -192 and -193 are smaller, fainter, and more oval shaped, also around stars.  Vogel: "Distance: 3200 pc, Sh 2-192, Sh 2-193 and Sh 2-194 are all near the W4 and W5 complexes." 


Sh2-196: 02 51 18.8 +62 13 53, 4': Very small, round, diffuse edges, with a slightly less bright central region, making it look like a puffy ring nebula.  8-inch Ha & dual band.  Sh2-192/-193/-194 trio on edge of field to the SW.  Vogel: "Distance: 3200 pc, This HII region lies between W4 and W5."

Sh2-195/-197: Maffei II.  I scanned around for this but did not find it.

Sh2-198: 02 50 01.0 +59 42 01, 9':  =Simeis 5.  Bright, small arc of nebula around a bright central star, with an extremely faint cloud of small nebula on the side of the star opposite from the arc.  This nebula lies on the southern periphery of the "Soul" nebula.  Vogel: "Distance: 2900 pc. This region is located towards the south of the W5 star formation area / radio source."


Sh2-200: 03 10 44.7 +62 48 55, 6' = PNe HDW2.  Difficult, extremely faint small ring nebula with a distinctive arc of 8 faint stars along its northern rim.  The nebula is thicker and extends to the north in a smudge.  8-inch only, dual band Ha+OIII.

Sh2-201: 03 03 10.3 +60 28 42, 5': Very weak small nebula around a bright star, a broken-up wedge shape with the northern end narrower than the southern.  Just off the "east coast" of the Soul Nebula.  

Sh2-202: A very large 2°x3° nebulous region in Camelopardalis, to the east of the Soul Nebula.  4-inch and Ha only, it was an extremely faint & heavily mottled contrast change from the rest of the sky, detected only by moving the telescope back and forth.  It is not included in Vogel's Atlas, but there are several good images online, such as this one from Dean Salman's Sharpless Catalog.

Sh2-203: 03 22 00.3 +54 52 40, 45': Extremely faint large cloud of nebula, very mottled and noticed as a weak contrast change when panning the scope, bordered to the east by a triangle of similar magnitude stars, 4-inch Ha.  Difficult.  

Sh2-204: 03 55 45.6 +57 25 45, 40': Long, faint, sharply bowed nebula, appears mottled like a breaking-up contrail, 8-inch Ha.  I did not detect the faint nebulosity within the arc, which shows up in this image.

Sh2-205: 03 56 07.7 +53 11 40, 120': Large, complex cloud, fairly faint, which fills the 4° field in the 4-inch.  -205 itself is an irregularly round cloud and the northern end, slightly brighter than the rest, and seemingly centered on a relatively bright star.  Vogel: "Distance: 900 pc.  The exciting star for this region is believed to be the O8 star HD 24451. Like Sh 2-202, this nebula lies at the edge of the Camelopardalis OB1 association."


Sh2-206: 04 03 13.1 +51 19 46, 50' = NGC1491.  Fairly large, around a bright star, with a very bright forked western rim slanting NE-SW, with layers of diffuse clouds rippling from it to the east and south from there.  4-inch Ha for perspective, 8-inch for detail.  Vogel: "Distance: 3700 pc, Size: 4.4 pc, NGC 1491 is an older, evolved HII region ionized by the O5 star BD +50 886."

Sh2-207 (04 20 04.0 +53 08 37, 4') A very weak, small round glow, diffuse, around a cluster of faint stars, seen with 4-inch Ha but better with 8-inch. Vogel: "Distance: 3400 pc, Size: 4.0 pc, despite its appearance, this is an HII region ionized by an O9.5 IV star and not a planetary nebula."  
Sh2-208 (04 19 45.5 +52 58 39 1'): extremely faint non-stellar roundness, seen with 8-inch Ha only.  Distance: 7600 pc, Size: 2.2 pc.  Contains the optical cluster Waterloo 1 and the infrared cluster [BDS2003] 64." 

Sh2-209: 04 11 03.0 +51 09 47, 14': Roughly round, small, very faint patchy glow, mingled with a small cluster of a dozen faint stars, noticed with 4-inch but better 8-inch, Ha+OIII.  Distance: 7816 pc, Size: 7.0 pc.

Sh2-210: 04 30 59.0 +52 33 10, 20': Seen with 4-inch, better 8-inch, diffuse round mottled cloud, with a brighter nub to the south around a cluster of faint stars, and a wind-blown mist of nebula fading from it to the north.  Distance: 2200 pc, Size: 12.8 pc.  

Sh2-211: 04 36 57.3 +50 56 22, 2': Very small but bright, brokenly round nebula around a close group of stars.  8-inch Ha.  Vogel: "Distance: 5154 pc, Size: 5.7 pc. Contains infrared cluster [BDS2003] 66 and may be embedded in the same CO cloud as Sh 2-212."

Sh2-212: 04 40 37.3 +50 22 52, 5': Appears as a small luminous, cloudy orb with slightly diffuse, mottled interior, brighter on the norther side, with a small tight cluster of faint stars in the middle.  Seen with 4-inch but better in 8-inch, Ha.  Vogel: "Distance: 6593 pc, Size: 18.2 pc. Contains the star cluster NGC 1624 and may be embedded in the same CO cloud as Sh 2-211."

Sh2-213: 04 20 42.9 +44 55 30, 1': Extremely faint, very small streak of nebulosity, appears as an elongated non-stellar glow, in a small tight open cluster (Berkely 11) of ~20 faint stars with 4 brighter.  8-inch Ha only, very difficult.  Vogel: "Distance: 5300 pc, Size: 1.5 pc. Sh 2-213 may be a very faint Stromgren sphere around a B4 class star in the cluster Berkeley 11. If so, it likely lies at a distance of 2100 parsecs."

Sh2-215: 04 17 32.8 +42 36 54 2': = Pa 167 planetary nebula. Very small extremely faint arc N-S and bending to the east, with a star in the northern tip.  This was quite difficult, 8-inch, Ha & dual band Ha+OIII, and a lot of patience only.  

Sh2-216: 04 44 56.9 +46 49 15, 80': = Simeis 288. Very large round glow, with a brighter northeastern rim, very faint mottled middle, and very subtle contrast changes to the western rim.  4-inch Ha.  The view this night was much duller than from a year ago, also from Pinnacles and with the same scope, but with a 0.5 better SQML reading.  Vogel: "Distance: 120 pc.  This is the closest known planetary nebula and one of the oldest."

Sh2-217: 04 58 47.1 +48 00 20, 9': Irregular round cloud, brighter in the mottled middle, with broken and diffuse edges.  Vogel: "Distance: 5200 pc, Size: 13.6 pc, Sh 2-217 contains 4100 solar masses of material."

Sh2-218: 05 41 16.4 +52 11 18, 70': Very weak feathered layers of cloud streaming W-E through some bright stars.  Large area >2°, best with the 4-inch, Ha.  No notes in Vogel but Galaxy Map says of it: "Very faint and diffuse nebula. Avedisova places Sh 2-218 in star formation region SFR 159.54+11.29 along with the dark nebula LDN 1460. BFS does not give a distance estimate for this object but in their notes describe it as a "bright dark cloud". The direction high above the galactic plane and the association with a dark nebula suggests a local dust cloud, but there are no significant references in the scientific literature to confirm this."

Sh2-219: 04 56 07.3 +47 23 43, 3': Small, fairly bright, round nebula with a spur to the west, a slightly offset over a bright star, with several fainter stars within the nebula.  The central area is mottled, and the cloud and soft edges.  4- and 8-inch, best in dual band Ha+OIII.  Distance: 4200 pc, Size: 3.7 pc.  

Sh2-221: 05 01 39.3 +46 20 56, 120': = SNR 160.4+02.8.  Need to hold bright Capella out of the field in order to see it.  Very large, excessively faint wispy nebula spread throughout the field, seen only as contrast change in the field and noticed by panning the telescope. 4-inch Ha+OIII only.  This is more difficult than Sh2-240 (Simeiz 147).  

Sh2-222: 04 30 09.2 +35 16 13, 6': = NGC1579. Wedge-shaped, chaotically mottled, with a bright core mixed with many stars, and diffuse edges with a faint tail trailing north.  4- & 8-inch, unfiltered and Ha & Ha+OIII showed different features.  Vogel: "Distance: 800 pc, Size: 1.4 pc, this dusty reflection nebula contains a cluster of about 5 bright B class stars and 35 other stars. The cluster is dominated by the massive young star LkHÄ® 101. 

Sh2-223: 05 17 11.1 +42 12 43, 70': = SNR 166.2+02.5.  Very faint large arc of feathered nebulosity, north to south with the bend pointed west, a little brighter and thicker on the northern end near some brighter stars.  4-inch Ha.  Distance: 8000 pc, Size: 162.9 pc

Sh2-224: 05 27 15.2 +42 58 16, 30' = SNR G166.1 +4.4.  Excessively faint curved cloud, with a relatively brighter, nearly bean shaped northeastern arc, and a thinner and even fainter parenthesis arc to the southwest.  4-inch Ha+OIII.  Did not see any feathering detail as shown in the POSS image.

Sh2-225: 05 27 00.3 +40 37 17, 10': Fairly small, very faint nebula to the east of a trapezium-like asterism, appears as a E-W wisp. 8-inch Ha only, did not see the fainter glow to the south as in the POSS image.  Distance: 3700 pc, Size: 10.8 pc.

Sh2-226: 05 11 06.6 +37 59 33, 3': Small fairly easily seen spike of nebula in a fairly rich field.  8-inch Ha.  Galaxy Map: "Little appears in the scientific literature about this nebula. It is more prominent at radio and infrared frequencies than hydrogen-alpha, suggesting that it is visually obscured. Avedisova places it in star formation region SFR 168.48-0.97 with two masers. It is near in the sky to the better studied Sh 2-228 and has a roughly similar distance estimate. Both nebulae appear to lie behind the Aur OB1 association in the outer galaxy."

Sh2-227: 05 19 52.8 +38 57 19, 20': Fairly large, diffuse cloud, almost a thick ring or doughnut with the center being less nebulous and with an offset relatively bright central star.  The northern portion is thicker with a prominent, if very small, streak in the northeast rim.  Obvious in the 4-inch and more detailed view with 8-inch, Ha.  Distance: 4300 pc, Size: 25.0 pc.  Galaxy Map: "Avedisova concludes that this little-studied nebula is ionized by the O9 V star LS V +38 12 [which is the exact center of the nebula and 1 magnitude fainter than the offset star I noticed]. It appears behind the western edge of the Aur OB1 association in the outer galaxy."


Sh2-228: 05 13 34.7 +37 27 12, 8': Fairly small but obvious irregularly round smudge of nebulosity, with a brighter central and many fainter ones (seen with the broadband filter) within the glow.  Vogel: "Distance: 7926 pc, Size: 9.2 pc, Sh 2-228 contains the massive infrared star cluster [IBP2002] CC01. (This is misidentified in SIMBAD as a possible globular cluster.) The 1800 solar mass cluster is 1 to 2 million years old, and the surrounding field stars about 5-6 million years old."

Sh2-229: 05 16 18.6 +34 27 48, 65':  Large, very bright central region chaotic with filaments of nebula, surrounded by a nest of wisps evaporating from it to the north, dissipating very slowly.  Best in the 4-inch Ha to take it all in, but also fun to see details with the 8-inch.  Vogel: "Distance: 510 pc, Size: 9.6 pc.  The Flaming Star nebula, IC 405, is excited by the runaway O9.5Ve star AE Aurigae, which is believed to have been knocked out of Orion's Trapezium cluster by an interstellar collision about 2.5 million years ago."

Sh2-230: 05 22 30.3 +34 07 55, 300': Huge comma shaped nebula, pretty bright, with N-S ripples through its many fine tendrils, very complex.  4-inch for perspective, 8-inch for details, Ha.  Vogel: Distance: 3200 pc, Size: 279.4 pc.  This enormous nebula appears to surround the Auriga OB2 association in the outer galaxy."

Overall, a very interesting part of the sky with nebula of different sizes and densities, which I spent quite a long time studying, 4-inch for perspective, 8-inch for detail, Ha & Ha+OIII. Vogel: "a giant molecular cloud containing Sh 2-231, Sh 2-232, Sh 2-233, and Sh 2-235 that is at a distance of about 1800 pc."  Galaxy Map: "Sh 2-231 to Sh 2-235 form a complex of HII regions located together in the Perseus arm in the outer galaxy. This complex may be associated with an old (330 thousand years) supernova remnant, FVW 172.8+1.5."
Sh2-231: 05 39 18.9 +35 55 30, 12': Compact but bright nebula around star, irregularly round.
Sh2-232: 05 42 26.4 +36 12 03, 40': Large, round, shot through with dark lanes, very diffuse with soft edges.
Sh2-233: 05 38 42.6 +35 47 35, 2': Fairly difficult, small, seen with 8-inch Ha only, very faint irregular mottled cloud.  It is not part of the bean shaped cloud to its west.
Sh2-235: 05 41 00.8 +35 51 15, 10': The brightest of the group, it is diffusely round with dark lanes in the western half, with two brighter stars in the south and northern rims.  


Sh2-234: 05 28 07.0 +34 26 06, 12': Fairly bright, large, with long arms extending from a chaotic bright central region, giving the impression of a spider (in fact it's nicknamed the Spider Nebula).  Vogel: "Distance: 2300 pc, Size: 8.0 pc. This is IC 417, sometimes called the Spider nebula. Sharpless 2-234 and 2-237 are together sometimes called the Spider and the Fly."

Sh2-301: 07 09 48.4 -18 28 43, 9': Fairly large, bright, the nebula is round and smooth rim on the east side, and more dispersed, diffuse, and nibbled by dark lanes on the west side.  Small faint stars clustered in the center.  Best 8-inch and dual band Ha+OIII.  Vogel: Distance: 5800 pc, Size: 15.2 pc, this HII region, also called Gum 5, may be associated with the GS234-02 star forming supershell."