willow springs midweek

Thursday night I arranged to observe from Willow Springs with Steve.  I really couldn't afford the time away from work, but I very much wanted to get out.  Steve had plans at Lake Sonoma but changed them for a chance of darker skies.

I brought my 20-inch, first time out in quite a while.  I finished doing the mechanical install of the ServoCAT but had not yet turned anything on, so I content myself with manual star hopping for the session.  I was already tired from a long day of work, and my note-taking suffered from lack of focus.

Before I began Steve showed me a finder chart for the Eridanus Loop, a second supernova remnant overlapping with Barnard's Loop.  I tried my 2x42 Vixens with various filters, and I thought I saw a N-S streak of something where it was supposed to be.  I could easily see Barnard's Loop, and the Rosette Nebula showed as a bright puffy glow.  Steve pulled Eridanus Loop Arc A up in his 24-inch, and we could see a brownish / muddy discoloration in the sky; best seen offset along its edge.  We were able to trace it for 2-3 degrees, including a kink in the stream.


I started out from Algol, intending to star hop up to IC 275:

NGC 1198: Small, fairly faint, brighter core with averted vision.  Two pairs of stars in the NE halo.  Very diffuse halo, 3:1 NW-SE, maybe spiral?  [E-S0, 12.5v]

IC 284: Bright foreground star at core, bright core, 4:1 fairly bright halo N-S, moderately large.  A non-stellar brightening to the W edge of the core [which turns out to be another galaxy, PGC 11646].  11.5v.

NGC 1177 & 1175: NGC 1175 is faint, moderately large, diffuse, brightens with averted vision.  3:1 NW-SE, with a brighter core.  Non-stellar glow to north of it, is NGC 1177, small, round, fairly faint, likely a pair [in fact these two are on the edge of AGC 426, with several more NGCs in the immediate area].

NGC 1164: Small, very faint, round haze, averted vision needed.  SBab, 13.1v

NGC 1193: Unresolved milky white oval shape, NW-SE, with a dozen stars resolved across face.  To NW is a pretty blue and orange pair of stars.

IC 275: Used 205x at first then 333x to try to see details. Largish mass of faint halo glow, with two brightenings near the center. I see another, smaller haze to the east, and another near an arc of stars [these are not galaxies, likely unresolved faint stars]. This is a group of three galaxies, PGC 11388 = A magnitude 16.5 elliptical galaxy (type E1?); PGC 11389 = A magnitude 16.3 elliptical galaxy (type E1 pec?); and PGC 11390 = A magnitude 15.6 elliptical galaxy (type E0?). I resolved the two brightest, but the third, PGC 11389, was not separated; its glow was likely combined with the other two.  ~460 mly distant.





NGC 1160 & 1161: Striking field.  NGC 1161 is smaller but brighter, irregular 2:1 N-S; looks like a reflection nebula shining by the light of two stars nearby to the west [S0, 11.0v].  NGC 1160 is a 3:1 NE-SW with gradually brightening core and diffuse halo, likely a spiral [Scd, 12.8v].

NGC 2438: PN in M46: Fat ring shape, ragged nebulosity inside the ring.  Two stars inside the ring.  Both OIII and UHC enhance the view.  It's a foreground object to the open cluster, and adds drama to the view.  Good in all powers.


CLR 5237: Calabash Nebula / "Rotten Egg" planetary nebula (since it is giving off sulfur).  This was plotted in Interstellarum, and so I supposed it could be visible.  Wrong.  I printed some finder charts and read one online reference that it was once seen as a "dim streak."  After much searching and confirming the star field (which is very close to NGC 2438), I noted an "excessively faint grey roundish glow a little east of the AAVSO finder chart position.  No central star unless the field star is it.  UHC seemed the best."  After getting home I realized what I saw was a roundish vacancy of stars to the east of where I was looking.  The nebula itself is extremely small, and when I search for Calabash nebula I find one positive observation in Jimi Lowrey's 48-inch telescope.  So why is this plotted in Interstellarum?  In this image, CLR 5237 is in the lower right corner, slightly bow shaped; note the round vacancy of stars just to its left; that's what I saw...



SaSt 2-3: Planetary nebula.  At 333x, appears as a faint star nearby to the SW of a brighter one.  Remains stellar with OIII.

Next I went up to Hydra's head and just looked for objects plotted on Interstellarum:

NGC 2644: Faint with a brighter mottled core, 3:1 N-S, with a faint extension / spiral arm looping up to the north then east. [Sc, 12.4].

IC 2420: Small bright core with a mass of halo sweeping up to the east, which could be the brighter part of a spiral arm.  [This is actually a round lenticular galaxy; the "spiral arm" I thought I saw may just be the unresolved faint star.]

BU 335: Close, ~1", 2 delta mag.  [Way off on the separation estimate; I found seeing / collimation may have been a problem with doubles during this session.]
08H 48M 12.24S +02° 34' 48.4" P.A. 266 SEP 2.7 MAG 7.46,9.41 SP F5 DIST. 153.37 PC (500.29 L.Y.)


NGC 2713 & 2716: NGC 2713 has a just stellar nucleus, compact round core, and a bright, surprisingly long halo, ~6:1 NW-SE, tapering slowly.  NGC 2716 to the NE in the view is small, round, but mottled -- maybe spiral arm to the north?  Bright core but not stellar nucleus.

NGC 2723: Galaxy is small, fairly faint, round but mottled, seems to have arms east and west sides.  Stellar nucleus with a foreground stars east and west of halo. [S0, 13.2; arm on west side may be unresolved stars.]

NGC 2729: Small, generally round, fairly faint, mottled, may be spiral.  Bright round core with a foreground star just east of core.  [S0, 13.4]

NGC 2718: Fairly bright, bright core elongated NW-SE, stellar nucleus, and oval halo [it is a barred spiral SBab 11.8v].  UGC 4703 is a extremely faint, very small non-stellar round glow 5' to the NW.

Per 1: double star: Tried a number of magnifications, but no split.  It's an orange-yellow star, suspected very faint star to the north but it's too far and intermittent with seeing.  Should have brought my off-axis mask!
08H 51M 13.71S +08° 20' 18.6" P.A. 354 SEP 0.8 MAG 8.30,9.59 SP K0

Leo I and IC 591: Leo I was very large greying of darker sky background, saw the round outline while panning around the field and with Regulus out of the field.  IC 591 is small, fairly faint, has a bright core and fainter halo, elongated 3:1 N-S; it is on the western rim of Leo I.

NGC 3130: In field with 31 Leo; can see the galaxy with the bright star in the field but view improves when keeping it out.  Bright core, just stellar nucleus, 3:1 NNE-SSW, some mottling in the core and halo.

IC 595: Small, extremely faint, round.  Averted vision brightens the core and small bright nucleus; diffuse halo.

NGC 3070 & NGC 3069: NGC 3070 is small, round, fairly faint, with a bright core, stellar nucleus, larger halo.  NGC 3069 is very small and very faint but has a long 5:1 N-S halo, bright core appears offset to south of halo.

NGC 3226 & 3227: Striking scene.  NGS 3227 is large, bright, with stellar nucleus and elongated core with faint tapering halo, 3:1 NW-SE.  NGC 3226 is a round to oval elliptical mass bordering the NE tip of NGC 3227, with a bright core & quasi-stellar nucleus, elongated 3:2 NNE-SSW.  Two galaxies either side.  I see two more galaxies on either side of 3227 [which according to the DSS image seem to be wispy ends of spiral arms of 3227! It is a SABa Seifert 1 11.79v]  3226 z=0.00423, 3227 z=0.00365, so maybe they are not interacting?  However the area is referred to as the NGC 3227 Group...

2M1134-2103: Quadruple-lensed quasar: I noticed this item in a post on Deep Sky Forum.  This and another lensed quasar were discovered in the last few months (pre-print published in January 2018 https://arxiv.org/pdf/1711.02674.pdf ).  One was ~19th magnitude, but 2M1134-2103 was around 16th, so I prepared some finder charts and gave it a try.  I found the field with low power then increased to 333x, and the star field matched the finder.  The quaser was very faint, stellar, not resolved to any components, and part of a trio of stars of similar magnitude.  I don't find any redshift value given for this one yet.

NGC 3763: Small, faint, bean shaped / irregular, 3-2 N-S, no core but a mottled haze.  5th magnitude Theta Crateris is very near to the NE and must be kept out of view. [SBc, 11.8v].  MCG-1-30-12 is on the opposite (north) side of Theta Crateris, in different field, and is a small, faint elliptical with a bright core.

Crater Globular Cluster, aka Laevens 1: This was plotted in Interstellarum, so I gave it a go.  I did not have a detailed finder chart, just a rough estimation from the atlas.  After a while staring at 333x I felt a "lucida" or brightening which reminded me of some Palomar globulars, within a triangle of stars.  I made a sketch of it and the surrounding star field.  Checking it on Aladin at home, I did sketch a string of stars very near to the globular, but the "lucida" I took for it was really an "over-density" of faint stars about 6' too far east.  This globular was discovered in 2014 and is likely the furthest away from the Milky Way center, some 470,000 light years (17x farther from the galactic center than earth).  It is thought not to be from the Milky Way, since it is too young (7b years).  It is thought to be a capture from the Small Magellanic Cloud, since its stars share spectral properties with SMC globular Lindsay 38, and it is found within the SMC debris stream.  It might also be leftover from an anonymous dwarf galaxy eaten by the MW.  In any case, why would Interstellarum plot such a no-see-um, except to have a "complete" list of all known MW globulars?