Tuesday, July 5, 2016

some planetaries and more

The night of July 2nd I met Mark Wagner and Mark Johnston for another session at Willow Springs 3000.  Transparency was very good with some haze around the horizon.  Seeing was variable – pretty good near zenith but not too great lower down; however it did improve overall after midnight.  Besides some of my Astronomical League project list targets, I did some free-range observing, wandering to objects on my Interstellarum Deep Sky Atlas which seemed interesting.  That led me to some unusual finds.  My thanks to Bob Ayers for the use of his property.

All in my 20-inch f/5.25 reflector:

NGC 6070, spiral galaxy in Serpens, @ 205x: Pretty large, fairly bright oval, SW-NE 2:1, with a clearly disrupted low surface brightness halo [which are the SA type spiral arms].  Brighter elliptical core with some knotting.  Faint star on SW tip of halo and two on the NE tip -- could be star forming regions?  [Aladin doesn’t say].  Best to keep bright star to north [HD 145204, 6.64 V] out of FOV.  I failed to notice NGC 6070A or B, just 4' and 5' to the NE.

UGC 10288, edge-on galaxy in Ser, 16 14 24 '-00 12 27, 14.2 V, Sc spiral, 4.023' x 0.483'. @ 205x: Faint edge on of mostly even brightness, gradually brightening to a small elongated core in the middle.  Quite long, 6:1 or more orientated precisely E-W.  DSS image shows a dust lane running the length and even disrupting the eastern tip. Surprised this is not an NGC!

Shane 1 = PN G013.3+32.7, @ 205x: Not too faint (12-13 mag) bloated star; OIII made it into a small round disk which blinks in and out.  Central star tentatively seen.  UHC has a good response.  Small arc of three faint stars just to the west.  Moderately rich field.

NGC 6172, elliptical galaxy in Ser, 12.9 V, 1.0' x 1.0', @ 205x: Small, round bright core with a very small / diffuse halo.  Forms a box with three other stars which lie just to the west.

NGC 6118, "Blinking Galaxy," Spiral galaxy in Ser, @ 205x: [Grand Design Sc II spiral, 4.7' x 2.0', 83mly].  Large, easily seen DV.  Halo is diffuse with ill defined edges, but I detect a gradually brightening center for a core.  3:1 NE-SW.  Why is it nicknamed Blinking?  Perhaps because AV helps it pop out a little from its surroundings; or helps it appear at all in moderate apertures.

NGC 5882, PN in Lupus, @ 205x: Very low (-45d 38m 58s)!  Unfiltered appears as a yellow-white sphere, boiling in the poor seeing with red flashes.  OIII pops it out strongly as a bright, even surface brightness disk with well defined edges.   No central star seen.

Havlen-Moffat 1, open cluster in Scorpius, @ 205x: Spray of 11 brighter stars in field, looks like a miniature Hercules constellation.  Hint of fainter small grey mist of unresolved stars at the bottom of the "keystone."  Bright star preceding.  [III 2 p]

NGC 6453, globular cluster in Sco, @ 333x: GC to 20' NE of M7, in same low power field.  Bright but not very resolved; moderately large irregular mass of unresolved stars behind a scattering of faint stars.  Two brighter stars on the eastern edge of the mass.

Minkowski M1-64, PN in Lyra, @ 333x:  Appears like a comet; fan shaped nebulosity with a star on the northern tip; almost a triangle.  [It is in fact a thick-ringed PN -- round with a dark interior.  The triangle may be an illusion due to the bright star on its rim.  I probably needed to use more magnification to see the ring.  It is, after all, referred to as "The Other Ring Nebula".  13.3 mag / 17.5'' x 17''].

NGC 6713, spiral galaxy in Lyra, @ 333x: [S0 13.4 v, 0.4' x 0.3'] Small, faint, oval slightly elongated ENE-WSW, slightly brighter to the middle with averted vision.  Rich star field.  Interesting to see it given the Milky Way plane is in the way.

Minkowski M1-92, PN in Cygnus, @ 333x: [Pre-planetary nebula, star drives high velocity collimated winds which shape and shock its shell.  11.7 v, 8’ x 16”.]  Very faint, small bloated star.  OIII elongates it very slightly, maybe NW-SE but hard to tell.  It brightens ever so little with blinking.

NGC 6853 / M27, Dumbbell Nebula, PN in Vul, @ 205x: Visible as irregular small grey patch in 80mm finder.  In the scope it is very large, nearly fills the field.  Bright bi-polar lobes SW and NE; apple core shape apparent; SW lobe is brighter.  Central star seen unfiltered in exact center, along with 8 more foreground stars scattered about.  Fainter nebulosity streaked with filaments fill in the empty core sections to complete the overall round shape of the nebula.  Streaks, knots, and condensations throughout the apple core area.  UHC has the best view; more stars and balance with the nebula.

IRAS 19477+2401, 19 49 54.5 +24 08 51, PN in Vul, @ 333x: "Cloverleaf Nebula".  This is plotted in Interstellarum and I “thought” I found it: a faint star which turns into a very small bluish blinking irregularly round glow with OIII; it is part of a triangle of stars of similar brightness.  But, looking at DSS images later I found the nebula is an extremely faint point just to the north side of one of these stars in the triangle, and not the one I thought was the PN.  It would be very cool if it were visible: it is a Pre-Planetary Nebula, a short-lived transition object between AGB stars and aspherical PNs.

Kohoutek K 3-35, PN in Vul, @ 333x: "Seahorse Nebula" [Very young planetary nebula with characteristic S-shaped radio emission morphology… one of two PNs with water maser emission detected -- means it's ejecting water into space!  See link for discussion of how the shape is being formed.]  In the scope, it appeared very small, extremely faint, out of round, and blinked with OIII.   It is the brighter of two very close stars; the other star is to the north and appears as an optical pairing; it doesn’t blink.  This one matched my sketch and a DSS image so I’m fairly confident of the sighting – but feel such an obscure object deserves a return visit for confirmation.

NGC 6857, emission nebula in Cyg, @ 205x: Pretty bright and large, it is irregularly round with diffuse edges.  OIII helps to bring out more nebulosity especially to a faint smudge heading west from the main body.  Very dense star field.

NGC 6888, EN in Cyg, @ 121x: “Crescent Nebula”:  Wow!  Amazing and large.  Triangle of bright stars to NE with a bright, thin band of nebulosity sweeping west and then south in an arc.  Continuing to the south, the nebula widens into a cloud with a prominent condensation at the SW rim.  Many faint stars interspersed within the nebula.  OIII makes it instantly brighter and completes the arc into an overall oval shape with streaks of nebulosity reaching back from SW to the NE.  But, UHC had the best view given the greater number of stars visible in the dense field.

NGC 6894, PN in Cyg: Unfiltered appears as a thick ring, slightly darker middle.  No central star.  OIII brightens the ring and adds highlights to the center.  There are differing bright and dark areas in the smooth round nebula; it looks like a primary mirror under Foucault test!

NGC 6723, GC in CrA, @205x: "Chandelier."   Large, bright, well resolved to the core.  Chains of stars seem to hang down from a concentration in the northern part of the core, thus its nickname.  Beautiful object. [7.3 V, 11' diameter].

NGC 6726-7, Bright Nebulae in CrA, @ 205x: Two fairly bright stars with nebulosity.  The one to SSW is 6726 [7.2 mag star] and NNE is 6727 [9.5 mag star].  Both nebulae are irregularly round and contact each other; look like porch lights in a fog, one house further away than the other.  To the SSE in the same field is another star with short cone-shaped nebulosity coming from it, appearing like a comet's tail [this is NGC 6729].  To the SW at the edge of the field is a pair of stars with more, fainter nebulosity; this is IC 4812 and it is illuminated by a double star.  There is general haziness in the sky in the view, part of the Corona Australic Molecular Cloud.

IC 1297, PN in CrA, @ 333x: Bright bloated star unfiltered, blinking disk with OIII.  Disk is bright with an even brightness, defined edges.  Central star seen, with very subtle darkening in the middle.  Very faint star on western rim.

NGC 6891, PN in Delphinus, @ 333x: Unfiltered, can see central star with averted vision.  Direct vision it is a disk with defined edges; seems to have an apple core shape within the round shell.  With OIII it has a bluish tinge and the "apple core" inside the disk is better defined.

Patchick 23, PN in Sge, @ 205x: Large (filled 60% of the 0.5* FOV), excessively faint, irregularly round.  Seen only with OIII, appears as a subtle greyscale difference less dark than the dark sky background, and moves with the telescope.  I offer this as a tentative observation; frustratingly I cannot find any information on the internet, even on the Strasbourg ESO catalog – though I’m probably entering “wrong” search terms.  I find some research papers written by Mr. Patchick, but none that reference #23.

Before turning in I made a half-hearted attempt at Pease 1 in M15; but is was past 4am and for the life of me I could not find the “trapezium” of stars which are, on my finder, the starting point to star hop to this object.  Will save it for another time.

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