I drove down Panoche Road, remembering all the times I went to Willow Springs. I wished I was headed there, up above a lot of haze. Oh well. I arrived well before sunset and dozed in the car. There was still a wildflower superbloom in progress, with pretty sheets of yellow, purple, and pink flowers spread over the grassy hills. Cattle grazing in the wide expanse, very bucolic. Not to mention all the pollen in the air, but I had prepared with myself with eye and nose drops. Not many cars passing by. I ate and started to set-up, Akarsh arriving just after sunset with his 18-inch dob. I used my 4- & 8-inch combo refractor and night vision. While still during civil twilight I observed the Horsehead, showing off. I continued my Sharpless project, missing a few items which had set by the time I got to them. Observed a few other things. I enjoyed observing with Akarsh, who is a serious and adventurous observer.
Highlights to start, then the rest of the items:
Fal 1: 06:58:50 -06:33:33: This is a recently discovered OIII cloud and is included on Arkash’s “Insanity” CalStar observing list. Apparently, the discoverer takes astrophotos of random parts of the sky, just to see what might be there. Using my 4-inch with PVS-14, I confirmed the star field with Akarsh’s laptop & planetarium software. I flipped through my filter wheel, and when I got to the Ha+OIII dual band filter, the nebula popped into view. It was pretty large, faint but obvious. There were two ragged sections of diffuse nebula, shaped like parenthesis, forming a large broken circle. The section to the west is considerably thicker and brighter, with mottling and streaking, while the eastern section is thinner, fainter, and more uniform. I didn't have the discovery image with me, and I did not notice the central round "ying-yang" nebula as anything separate from the main. Next time I'll take a more careful look. I don’t think it’s been determined what the cloud is, but my guess is an ancient and/or nearby planetary nebula, the clouds of which have started to break up against the interstellar medium.
Fal 1: 06:58:50 -06:33:33: This is a recently discovered OIII cloud and is included on Arkash’s “Insanity” CalStar observing list. Apparently, the discoverer takes astrophotos of random parts of the sky, just to see what might be there. Using my 4-inch with PVS-14, I confirmed the star field with Akarsh’s laptop & planetarium software. I flipped through my filter wheel, and when I got to the Ha+OIII dual band filter, the nebula popped into view. It was pretty large, faint but obvious. There were two ragged sections of diffuse nebula, shaped like parenthesis, forming a large broken circle. The section to the west is considerably thicker and brighter, with mottling and streaking, while the eastern section is thinner, fainter, and more uniform. I didn't have the discovery image with me, and I did not notice the central round "ying-yang" nebula as anything separate from the main. Next time I'll take a more careful look. I don’t think it’s been determined what the cloud is, but my guess is an ancient and/or nearby planetary nebula, the clouds of which have started to break up against the interstellar medium.
Sh2-247: 06 08 30.2 +21 37 12, 9’: With 8-inch and Ha, it appeared very bright, fairly large, round, full of billows of cloud giving the impression of a spiral galaxy, bordered on one side by a nearly straight dark cut-off and with a central star. A smoke of nebulosity trailed off from one side toward Sh2-252. Vogel says: “Distance: 2000 pc, Size: 5.2 pc. The Sh2-247 molecular cloud is part of the Gem OB1 complex, contains 37 thousand solar masses at a distance of 2200 pc and appears to be physically connected through CO filaments with Sh2-252. The exciting star is LS V 21 27 (B0 III star).” Surprisingly, given how bright this appeared to me, Vogel reports “no certain observation” with his 22-inch.
Late at night, as the Milky Way rose, I scanned around with the PVS-14 mounted on a monopod, viewing 1x with an Ha filter. I enjoyed all the favorites: North America with the nebula connecting it to Cepheus on one side and Sadr on the other; the Veil Nebula; the very bright Lagoon, etc. I was able to observe two Sivan nebula which had set by the time I tried to observe them last summer:
Siv 10: 16 01 00.0 -20 19 00, 840'720’, 14° x 12°, 174 pc.
This nebula lies in between the Scorpion’s head and Sh2-27, the large bright cloud which many observers with night vision have noticed. It was faint, but obvious, large, round with an arc of brighter nebulosity along its NE rim. The center was mostly diffuse but had a slightly brighter and mottled “core,” and there was a bright puff to the south. Sivan says of it; “Almost circular emission region containing two concentrations, S1 and S7 surrounding the stars Pi Sco and Delta Sco respectively. Appears to be associated with an expanding shell of neutral hydrogen connected with the II Sco association (Sancisi 1973).” Color image from Finkbeiner's H-alpha full sky map.
Siv 8: 16 43 24.6 -41 23 45, 420'x420', 7° x 7°, 2000 pc. This is at the southern tip of the Scorpion’s tail, and appears as an obvious, if faint, wreath-shaped cloud, with IC 4628 the Prawn Nebula as a very bright bow on it’s NE rim. There was a large sheet of nebulosity flowing further south to the horizon, a bright knot of which is NGC 6188. I also examined this through both the 4-inch and 8-inch scope, seeing a lot more wisps and billows, and very excitingly the pillar of dark nebulosity along the northern rim, which looks like a much larger version of the Cone Nebula. Sivan says: “Wheel-shaped nebula, possibly connected to RCW 114 by faint, outlying filaments. Contains RCW 113 and IC 4628. Connected with the Sco OB1 association. The derived linear diameter is 244 pc.”
Sh 2-248 = IC 443: 06 16 38.4 +22 30 01, 50’. Known as the Jellyfish nebula, for its bright dome with fainter wisps floating down from it toward the bright star Propus. These filaments curve and flow laterally away toward the bottom (SW section of the nebula). Vogel reports the southwest filaments as being extremely faint with his 22-inch, but they were quite easy for me. Vogel: “Distance: 1500 pc, Size: 21.8 pc, “3000-year-old Gem A supernova remnant (SNR 189.1+03.0).”
Sh 2-249 06 20 58.1 +23 05 23, 80’. Sh2-249 was in the same field with Sh2-248 with the 4-inch, and appeared large, diffuse, and bifurcated by a tree-like dark nebula (like a larger, fainter version of the Flame Nebula), near the bright star Mu Gem. Vogel: "Distance: 1600 pc, Size: 37.2 pc. This HII region is excited by members of the Gem OB1 association."
Sh2-268: 06 10 14.6 +13 19 55, 60’: Incredibly faint, large ring, seen with 4-inch and Ha and only by moving the scope to notice it. Brightest section to the east mingled with a ragged stream of 5 stars. Distance: 1300 pc, Size: 22.7 pc.
Sh2-302: 07 31 41.0 -16 58 43. 21’: 8-inch Ha, an irregularly round glow, irregularly bright, with two bright stars at NE and SW sides, and sprinkled throughout with fainter stars. There is a distinctive dark lane splitting the eastern rim from the rest. Vogel: “Distance: 1800 pc, Size: 11.0 pc. Also called RCW 7, Sh 2-302 is part of molecular cloud A in front of supershell GS234-02.”
PuWe 1: Purgathofer-Weinberger 1 = PGN 158.9+17.8, 06:19:36 DEC +55:37:00. Tried for it at Akarsh’s suggestion. With 8-inch and Ha, it was an extremely vague, medium-sized (half a degree?) round glow with diffuse edges, noticed when moving the scope but can then hold it direct. Image from Andre van der Hoeven, who gives some additional information about the object: "The nebula has an estimated diameter of about 4 ly, and therefore is probably a very old remainder of a planetary nebula that has expanded that far that the remaining gases are only weakly energized by the central star."
Sh2-242: 05 51 50.7 +27 00 38, 7': Appears as a ragged, mottled fan with the 4-inch and Ha. With the 8-inch, it is much brighter, and the thicker sides pop out from the murkier middle. The long back edge of the fan is diffuse with faint trailings of nebulosity dragging behind it east. Vogel: "Distance: 2100 pc, Size: 4.3 pc. This HII region is excited by a B0V star and appears to lie at a distance of 2700 parsecs."
Sh2-241: 06 04 06.7 +30 14 52, 10": With 4-inch and Ha, faint but quite apparent, larger than Sh2-242, looks like a comet emanating from a small bright cloudy come, with a blunt, fan shaped tail extending southwest, the sides of which are much brighter than the rest. Vogel: Distance: 4700 pc, Size: 13.7 pc. The exciting star for this nebula is the O9V star LS V +30 31. The nebula is a blister on the side of a molecular cloud at 5300 +/- 1100 parsecs. This field also contains the reflection nebula vdB 65 at 1100 parsecs, which is a completely unrelated object."
Sh2-244: M1 = NGC1952 = Crab Nebula, 05 34 30.4 +21 57 09, 5': Irregularly shaped oval, mottled interior, soft edges, viewed in both 4- and 8-inch, Ha+OIII dual band. Distance: 1930 pc, Size: 2.8 pc. This is the Crab nebula supernova remnant.
Sh2-245: 04 02 32.8 +04 07 42, 720': 4-inch Ha, a very weak and long streak, seen when moving the scope only to notice the contrast change. The streak has different thicknesses and is somewhat mottled. This is just a small section of the Eridanus Loop, which is much better seen -- it's pretty bright, actually -- at 1x. Too much magnification and a smaller image scale is not the right way to observe this object.
Sh2-246: 05 02 08.9 +14 05 44, 65' 4-inch and Ha only, very extremely faint contrast change running N-S to the background sky, through a very pretty zig-zag pattern of stars which run NW-SE. With attention I notice mottling or unevenness, and it's quite large. Vogel: Distance: 3700 pc, Size: 70.0 pc. Sh 2-246 is visible in the direction of Lynds dark cloud LDN 1562, which together with Lynds dark cloud LDN 1563 forms a local dust ridge located well below the galactic plane at a distance of 180 pc, and is part of the Taurus dust cloud complex within the Gould belt, our local stellar neighborhood. Avedisova concludes that Sh 2-246 and LDN 1562 are part of the same star formation region, SFR 186.96-16.58. If Sh 2-246 is actually embedded in this dust ridge, it must be much closer than the distance estimate given here.
Sh2-265: 05 18 36.3 +07 26 23, 70': 4-inch and Ha, Broad, diffuse, large, running mainly W-E, bifurcated with a brighter / thicker wing to the N, and fainter more uniform wisps to the south. Vogel: Distance: 400 pc, Size: 8.1 pc. This diffuse HII region is part of the B223 section in the southern part of the Lambda Orionis ring (most of which forms the huge Sh 2-264 HII region). However, Sh 2-265 is not ionised by Lambda Orionis itself. Instead it is probably ionised by stars in the Ori OB1b association.
Sh2-266: 06 18 48.9 +15 16 40, 1': 8-inch only, difficult, very small non-stellar glow around a star, identified only with comparing the star field to the POSS image, no detail seen. Vogel: Distance: 6000 pc, Size: 1.7 pc. This may be a ring nebula surrounding its central star, the Be class supergiant MWC 137."
Sh2-269: 06 14 34.1 +13 49 18, 4', Distance: 3800 pc, Size: 3.9 pc.
Both are fairly difficult, seen as very small puffs with the 4-inch & Ha, brighter with the 8-inch, with -269 being more densely bright and -267 more diffuse. The dark lane splitting -269 was well seen.
Sh2-270: 06 10 12.9 +12 48 55, 1': Small round non-stellar glow, 8-inch Ha only, identified by comparing the star field to the POSS image. This really requires a larger aperture. Distance: 6800 pc, Size: 2.0 pc.
Sh2-271: PK 197-02.1 06 14 54.3 +12 21 14, 2'
Sh2-272: 06 15 00.3 +12 20 14, 1'
-271 is larger but just a faint puff seen with the 8-inch only, -272 is much smaller and seen with averted vision and only after studying the POSS image for its location. Vogel: Distance: 4800 pc. Includes infrared cluster [BDS 2003] 82. There is confusion in the literature about whether this is an HII region or planetary nebula
Sh2-273: NGC2264 = Christmas Tree 06 40 48.3 +09 54 28, 250': Fox Fur, which I have seen many times, all details seen with 4-inch & Ha, including the Cone Nebula. Vogel: "Distance: 800 pc, Size: 58.2 pc. The Fox Fur nebula is associated with the star cluster NGC 2264, dominated by the O7Ve multiple star system S Monocerotis (usually abbreviated to S Mon). This region also includes the famous Cone nebula, visible at the bottom of the image.
Sh2-274: Abell 21, 07 29 06.4 +13 15 43, 8': 8-inch and Ha+OIII dual band, a mottled and streaked crescent moon nebula, rather large, with an excessively faint curved band opposite (NW band) trying to close the circle. Vogel: "The Medusa nebula, Abell 21, is a planetary nebula located at a distance of about 188 pc and is 8800 years old."
Sh2-278: 05 19 48.2 -05 39 49, 50': A few degrees east of M42, but never noticed: Wedge shaped with the brighter tip pointed east, and fainter wings spreading out from it and fading very slowly and faintly into the background. 4-inch Ha. Vogel: Distance: 500 pc, Size: 7.3 pc, this is the high latitude cloud MBM 110."
Sh2-280: 06 34 18.7 +02 32 23, 40': Large diffuse cloud orientated NE-SW, bifurcated to two bright wispy halves, with a diffuse fog curling from the SW end up to the north. 4-inch Ha. Vogel: Distance: 1700 pc, Size: 19.8 pc, The exciting star for this HII region is HD 46573."
Sh2-282: 06 37 58.5 +01 30 51, 35': Large diffuse nebula running N-S, with some wispy streaks and puffs of nebulosity to the north, it looks like a footprint. Worth another look with more aperture as I missed the cometary globules. Vogel: "Distance: 1500 pc, Size: 15.3 pc. The exciting star of this HII region, HD 47432 (the bright star in the upper part of the image), is located at a distance of 1250 pc and is probably a member of the Mon OB2 association (whose distance is usually given as 1550 pc). The HII region contains a system of eight cometary globules."
Sh2-284: 06 45 02.0 +00 13 51, 80': Extremely weak large round glow, with an inner ring of faint stars. 4-inch Ha. Vogel: Distance: 5200 pc, Size: 121.0 pc. This large HII region is associated with the star cluster Dolidze 25 and is one of the few relatively unobscured major star formation regions in the outer galaxy."
Sh2-285: 06 55 12.2 -00 30 37, 1' Small non stellar glow with a very short comet-like tale to the south, 8-inch Ha only. Vogel "Distance: 6900 pc, Size: 2.0 pc. Contains at least two B0 V stars and the infrared cluster [BDS2003] 85."
Sh2-286: 06 54 32.6 -04 30 32, 6': Very faint round glow, a little brighter in its eastern half and diffuse and with fading edges to the west, 8-inch Ha. Distance: 6600 pc, Size: 11.5 pc. Contains the infrared cluster [BDS2003] 88.
Sh2-287: 06 59 32.3 -04 48 14: 12' Patchy cloudiness following an arc of five moderately bright stars, 8-inch Ha. Vogel: "Distance: 2100 pc, Size: 7.3 pc. Sh 2-287 appears to be associated with Maddalena's cloud (G216-2.5). It contains 4000-5000 solar masses of gas and dust and a bipolar nebula, NS 14."
Sh2-288: IC 466 07 08 33.0 -04 18 30, 1': Small, bright glow around a star, and a very faint and small diffuse cloud around that brightest concentration, 8-inch Ha. Distance: 3000 pc, Size: 0.9 pc. This HII region, also called IC 466, is ionised by an O9V star."
Sh2-289: 06 45 56.3 -07 20 18, 11': Fairly large amorphous round glow, with a stronger concentration to the south, mingled with many stars. 8-inch Ha. Distance: 10100 pc, Size: 32.3 pc
Sh2-290: Abell 31 08 54 10.5 +08 55 16, 17': Fairly difficult, 8-inch Ha+OIII, diffuse round cloud with brighter/sharper southern rim, mottled central region, and diffuse and broken northern rim, with a distinctive L-shaped asterism in the middle.
Sh2-291: 06 55 24.6 -08 01 40, 8': Small, faint, oval puff, diffuse to the south. 8-inch Ha. Distance: 8500 pc, Size: 19.8 pc
Sh2-294: 07 16 34.3 -09 26 38, 7': Small bright clotted concentration of nebula, with a fainter lobe to the north, and a very faint wisp of cloud to the north of it. Vogel: "Distance: 4600 pc, Size: 9.4 pc. This HII region contains the loose infrared star cluster [BDS2003] 95. Its odd shape looks like an upside down octopus - should it perhaps be called the Octopus nebula?"
Sh2-313: Abell 35 12 53 31.0 -22 51 35, 12': Extremely faint, rather large round diffuse glow but with two bright streaks running E-W through the southern half. Tough. 8-inch Ha. This is the planetary nebula Abell 35. Like Sh 2-52 (Abell 65), it has a highly unusual binary central star. It probably
lies at a distance of 160 pc."
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