21 april 2024 movement pairs

Seeing was predicted to be good during the first half of the night, and excellent after 1am.  I opened up the 20-inch and hoped I could go after some pairs from my "movement" list.  I did catch a few.  Seeing was ok but not perfect.  A haze blew in from the ocean most of the night, getting thicker after midnight.  There was a nearly full moon, and the sky was filled with its glow because of the haze.  For the first few hours the moon was hidden behind the large meridian tree in a neighbor's yard, but eventually came out.  Since seeing didn't improve all that much I spent a half hour on the moon before closing up at 1am.

HU  718 AB: 508; 635x: With seeing, fainter B is seen with PA SW, good close split at this power (currently 0.237").  SOC grade 3 orbit, 140-year period, it is widening to apastron in the mid-2030s. 

09h 00m 30.68s +32° 25' 03.2" P.A. 42.00 sep 0.237" mag 9.30,9.49 Sp G5 dist. 89.05 pc (290.48 l.y.)

B  2530 AB: 508; 635x: Using the peephole in my eyepiece cap, I see an elongation with a weaker end tht the SE.  No notch visible, but an obvious magnitude difference. SOC grade 2 orbit, 34.8-year period, it will reach apastron in its nearly edge on orbit in 2030, then rapidly close to periastron in 2040.

09h 27m 46.78s -06° 04' 16.4" P.A. 143.00 sep 0.405" mag 5.63,7.52 Sp G2V dist. 30.41 pc (99.2 l.y.)

HU  716 AB: 508; 425x: Lovely light orange stars, >1 Dm, nice split at this magnitude, PA ESE.  This will close rapidly and turn E then N by 2045.

08h 31m 35.03s +34° 57' 58.5" P.A. 42.00 sep 0.491" mag 7.58,9.02 Sp G5 dist. 28.22 pc (92.05 l.y.)

BU 1422 AB: 508; 280x: Wide pair, near equal is the HJ, the BU is more closely separated, around 2", 1 Dm, B appears with foveal coaxing out of nowhere. -9% PRO, it is not likely binary.

09h 21m 12.70s +27° 27' 59.6" P.A. 358.00 sep 1.9 mag 10.47,12.90 Sp K0

A  1088 AB: 508; 1270x: Very weakest of elongations, appears the weak end is to the SSW, very difficult.  SOC grade 3 orbit, 134.9-year period, it is widening to split-ability by the mid-2030s to 2040s at around 0.25".

12h 00m 37.54s +69° 11' 07.8" P.A. 2.00 sep 0.196" mag 7.88,8.81 Sp F2V dist. 206.19 pc (672.59 l.y.)

BU  794 AB 508; 1270x: At all high powers, in moments of finest seeing, I see a very elongated & very subtlety notched pair on a W-E line, guess weaker is to E.  SOC grade 2 orbit, it will make a quarter turn to the south by 2050.

11h 53m 43.07s +73° 45' 21.6" P.A. 63.00 sep 0.506" mag 7.23,8.32 Sp F8V dist. 58.17 pc (189.75 l.y.)

2024 eclipse

We didn't travel to see the April 8, 2024 eclipse over Mexico and North America, though I wanted very much to.  The event was on the first day of school, and amazingly all the kids wanted to be in school.  Lin wasn't excited about it.  I think all of them associate eclipses with the mosh pit that was the county fairgrounds in Madras, Oregon, where we camped out to see the 2017 eclipse.  Except for the eclipse itself, it wasn't a good experience for anyone.

So I contented myself with viewing the partial eclipse from home.  Fortunately we had good weather and good seeing.  I used my long focal length singlet solar projector, which showed a nice image but the tracking is off so it wasn't convienent.  I mainly used my 6-inch with the quark.

I studied the prominences hanging off the sun's limb because I knew I would be able to see the moon in front of these features before first contact.  And sure enough I was able to watch the moon slowly cover over two large prominences, including a distinctive V-shaped one which was visible during totality by the naked eye.  As the eclipse was ending, I watched as these prominences re-emerged from behind the moon.  

During partiality I enjoyed seeing the uneven line of the moon's curved shape -- crater mountains as so on -- silhouetted across the sun.  Filaproms disappeared and reappeared and were partially covered by these subtle irregularities in the shadow.  

I invited my neighbor Gary who brought along his mother-in-law, who is from New York and who looked uncannily like my own mother -- there might be some distant relation.  She had never looked through a telescope before but eventually was able to see the prominences.

They left soon after full partiality.  In fact a lot of observers stopped observing, as if the climax of the show was all the show to see.  I continued to watch the moon's shadow as it approached final contact.  It seemed to accellerate as it moved further off the sun, but of course this was an illusion of perspective.  Smaller prominences reappeared along the sun's limb.  Best of all was watching the moon through final contact: I saw the hacksaw-blade looking chromosphere along the limb of the sun, separated by a thin black line.  As the moon moved off the limb it was still covering this very thin feature appeared as wedges on both sides, rapidly moving toward the point of the moon which made last contact, filling up the wedges with the tiny blades which popped up whole as the moon moved away.  Difficult to describe but very interesting to watch.

Perhaps we will be able to make arrangements to see future eclipses at totality.  I hope so!

another weekday dark sky

Once again, a dark sky window opened on a Tuesday night.  By luck my work schedule was clear Tuesday afternoon, for the drive down, and Wednesday morning, for the drive back.  I went back to the "tranquility base" site, arriving at 7pm.  This time I brought my 4-/8-inch combo refractor, ready to be more productive in my observing.  After setting up I had my picnic dinner, and watched the day-old moon, fresh off its eclipse the day before, setting behind a nearby rocky ridge.  Its earthshine shown in the darkening dusk, and I had the privilege to watch first the thin bright crescent, then the moonshined sphere itself, set behind the ridge.  

After it being more fully dark, I quickly swept up Pons-Brooks near Jupiter in both the 4-inch and 8-inch.  It had a stumpy, broad fan shaped tail, but I did not see any long extensions coming off it.

I didn't have a set observing plan, though I did use my atlas to find different objects in various parts of the sky.  First up:

NGC 2354: An open cluster in Canis Major, which was a large rich round cluster with a pretty curved main stream delineated by a N-S lack of stars.  10 bright stars and numerous, easily 100, faint stars.   This picture shows a view similar to the low power 4-inch's field, with night vision -- the cluster is just right of center.

ESO 428-29: A small, bright elliptical galaxy close to Eta CMi.  Picked up easily in the 4-inch.

After checking out M46 & M47:

Cluster of open clusters, within the same field in the 4-inch: 

Ru 151: Fairly large, round and faint cluster, well separated, fairly rich with faint stars, with a bright star dominating the center

NGC 2428: Tight group of several bright stars in the middle of a large, round cluster, well defined, backed by another 50 or so fainter stars.

NGC 2430: fainter and smaller than the other two, still well seen and fairly well separated from the rich Milky Way field, it is fairly concentrated and probably 30-40 stars.

I tried once more for the Procyon Nebula.  Knowing it was to the east of Procyon, I held the bright star out of the field and used both 4- and 8-inch and flipped through my filters.  I consistently saw a patchy contrast change from the background sky in the 7nm & 3nm Ha filters, vaguely fan shaped and extending roughly 1-degree from Procyon.  But when I pan around the area, I notice other wispy patches of contrast change, which I believe are part of the Orion-Eridanus Super Bubble.  So I am not really sure if I saw it -- since the nebula is depicted in Finkbeiner as being quite bright.  I contacted Kevin Jardine, who runs the Galaxy Map site, and he said not to read too much into Finkbeiner's low-resolution composite.  There are several other bright stars which have nebula showing up around them, so I'm not sure how to understand this: is it sensor artifacts, or a very localized ionization of hydrogen and not an HII region per se?  

I skipped a lot of objects because they were too small to be enjoyed with my scopes.  I really must do something about the image scale, or get a large aperture dob for dark sky outings.  I did, however, return to some of the nebula I had observed at 1x the week before for a closer look:

RCW 19 = Gum 10, & RCW 20: Finally, a nebula I could explore with more certainty!  This was pretty bright and showed well in the 3nm filter in both the 4-inch and especially the 8-inch.  There is a bright and nearly round patch at the NE end of this long nebula, which in the 8-inch reveals two dark nebula / elephant trunk structures intruding into it from the north.  These were still small scale, but very clear.  The rest of the nebula trailed off to the SE and was generally diffuse and heavily mottled, though the nebula expanded again into a large puffy cloud at the SE end (RCW 20).  Galaxy Map says RCW 19 "is part of a 200 thousand solar mass giant molecular cloud related to the Pup OB3 association and the O7f III giant star HD 69464. This image shows only the bright rim of the larger RCW 19 complex.  Avedisova adds the O9.5 III giant CD -35 4412 as a second ionizing star. She places RCW 19 in the star formation region SFR 253.75-0.50 with the molecular cloud [MAB97] 253.63+0.00 (this may be the cloud mentioned above) and the reflection nebulae Bran 124b, Bran 125b and VdBH 9.

NGC 2467: This very exiting nebula immediately impressed with its two large butterfly-like wings.  The bright concentration is the NGC itself, a round bright nebula centered over a star (Haffner 19 a compact cluster containing a Strömgren sphere which is ionized by a hot B0 V-type star).  From there a bright thick fountain of nebula forms one wing, and a brittle dark lane separated it from the other wing sprouts from a bright knot (Haffner 18, which contains a very young star, FM3060a, that has just come into existence and still surrounded by its birth cocoon of gas).  The rest of this wind is fainter, more diffuse and with a dark nebula running the main length, but larger, especially the top of the wing which trails off quite a distance and tapers.

RCW 27: A fine nebula in the large, loose open cluster Ru64, which consists of 10 brighter and countless fainter stars over a 1-degree area.  With Ha, the nebula is larger than the OC, overall round, thick doughnut shaped with crenellated edges, with a brighter quadrant to the SE.  It appears to be shot through with finger-like dark nebula, especially separating the SE and eastern segments (dark nebula SL 1).  It is very reminiscent of the Rosette nebula, but smaller and fainter.  The bluish, non-stellar glow in the lower right of this astro-photo is the reflection nebula NGC 2626.  I did not notice it in NV (which doesn't do well with reflection nebula with blue wavelengths generally).  Galaxy Map notes "RCW 27 lies in the same direction as the reflection nebula association Puppis R2 in the Vela molecular ridge. A major contributor to the ionization of RCW 27 comes from the O star HD 73882. (SIMBAD gives an O9 III class for this star.) The reflection nebula NGC 2626 is part of the same complex."

Gum 15 & Gum 17: Gum 15 is smaller than RCW 27, but brighter.  It is a mostly round puff centered on a bright star, heavily mottled with dark nebula, and with some viewing appears like a cave lit within by a fire -- the bright star clearing gas and dust from around itself.  It looks like a smaller version of the Trifid Nebula.  There are faint nebulous streams wafting faintly from Gum 15 to the NE.  Wikipedia says "located in the constellation of Vela, Gum 15 is about 3,000 light-years from Earth.  It is shaped by aggressive winds flowing from the stars within and around it. The bright star in the center of the nebula is HD 74804, a double star."

To the SE is Gum 17, more than 2x larger but more diffuse and fainter.  It is also round and mottled, with very faint dark nebula crackling through it.  

NGC 2658: Open cluster in Pyxis, it is small, round, rather faint and slightly difficult to separate from it surroundings, moderately rich. 

I moved on to view galaxies.  I used the 685nm filter the most, and sometimes unfiltered.  I took a tour of the Virgo Cluster, and of course found that NV at the relatively small aperture 8-inch, would show me galaxies just fine (as well as I remember my 20-inch in dark sky showed visually), but they are on a small image scale and not easy to appreciate.  I did change my afocal set-up from 67mm to 40mm, but the smaller exit pupil dimmed the sky so much I lost view of some galaxies.  I tried the Hydra cluster, and I could easily see NGC 3309 and NGC 3311 in a brighter clump between two stars, but the other galaxies were small faint imperfections in the sky darkness: I knew they were galaxies, but they were unsatisfying to look at.  The only way to have more image scale is to use more aperture.  I wish the Challenger scope was easier to use; otherwise, I need to beg others' time to observe on their large dobs or go and buy one for myself.  As it was, I stuck with the brighter, larger objects, knowing it' the most I could get out of the equipment at hand.

One good thing about NV and galaxies is it really helps with edge-on flat galaxies.  In flat galaxies, the dust has blocked blue wavelengths and red predominates, and red is more visible in NV.  I will plan my next spring outing on flat galaxies and globular clusters, and hopefully have a more enjoyable experience.

NGC 2997: Small bright core, diffuse halo, seems slightly inclined -- it's a face-on spiral with strong arms on either side, making it appear inclined to me at low magnification.

IC 2469: Gorgeous, ghostly near edge-on, NE-SW, bright nucleus, fairly bright halo is very long tapers to thin points, is a very rich field.  A faint star is next to the nucleus on the SW side.

A trio of flat galaxies, in a line NE-SW, about equally spaced from each other, look in the field like three tossed coins.  NGC 4216: The largest of the three, in the center of them, it has a bright core, well elongated and thin edge on, NNE-SSW, mottled along the edge especially to the NNE side.  To its SW is NGC 4206, very faint, emerges from the dark, about half the size of NGC 4216, it stands nearly N-S and has a bright nucleus and thin tapering tips.  NGC 4222 is to the NE, the smallest of the three, faint, very elongated NE-SW, close to a fairly bright star to its east.  Really beautiful scene with these three flat galaxies.

NGC 3109: Difficult large faint flat galaxy, very long, 4:1 NE-SW, weak core, it seems to melt into the background.

NGC 3087: Small elliptical with a bright core in a triangle of similar magnitude stars

M61: Bright core, round and diffuse halo which is cut off sharply along the SE side.  Did not notice spiral arms.

M58: fairly large round halo and bright core.  NGC 4567 and NGC 4568, both inclined, elongated galaxies, of similar brightness and size, nearly touch the outer edge of their halos, form an arrow shape.  Very small round non-stellar glow nearby is NGC 4564.

NGC 4927: Elongated, pretty bright, small.  Nearby in a 90-degree difference in position angle is NGC 4536, smaller and fainter (I didn't notice the round halo of this face-on spiral).

NGC 4037: Nice, elongated galaxy, bright nucleus, diffuse 3:1 halo N-S.

M83: Bright nucleus, comparatively large round halo with some hints of spiral structure on the NW side.  I think this would look better with even moderate aperture with glass.

NGC 5102, Iota (Centauri)'s Ghost: A slightly elongated elliptical with fairly bright core near the very bright star.

Omega Centauri filled the 8-inch's 2-degree field, and looked pretty good despite some haze which had built up on the low horizon.  

I tried pretty hard to see ESO 270-17, Fourcade-Figuerora Object, but could not.  It's a galaxy "shred," the remnants of a galaxy which merged with Centaurus A and appears similar to a flat galaxy.  I could see Centaurus A, and its distinctive dark lane, just fine.

I then switched to visual (!) observing.  Using the 8-inch, I found

Abell 35: Weak partial C-shaped glow, with OIII.  Of course what I saw was only the brightest, thickest portion of the nebula.  

NGC 4517: Beautiful, very long flat galaxy, ENE-WSW, very subtly mottled halo, bright nucleus.  A star, brighter than the nucleus, touches the northern edge of the halo.  

NGC 4565: "The Needle": Gorgeous flat galaxy running most of the field SE-NW, clear dark lane splitting the mottled halo which tapers to sharp tips, bright round nucleus. 

weekday dark sky

Tuesday the 2nd seemed the best chance for a dark sky this new moon, so I took it.  I needed to get a lot of work done during the day and take calls during the drive down, but I was able to fit it in ok, and get back the next morning to resume work with only a couple hours sleep.

I went to "Tranquility Base" in the central coast range.  The usual route was closed, so I followed the longer dirt road.  I noticed a couple cars heading out as I was heading in.  One person drove past around midnight, likely a hunter as his dogs were barking and yelping in the back of the pickup truck -- but otherwise I had the place to myself.  Seeing was poor in the beginning of the night but improved.  It was dark -- 21.3 by astronomical twighlight, and a peak of 21.55 around 1am -- as I found the next morning driving home, a thick fog covered the Salinas valley.  

I brought my NP101 and C8, and it was a rather difficult night.  I have trouble balancing that set-up, and if I want to observe an object with the 4-inch, I have to move the NV set-up to the other scope and rebalance.  It wastes a lot of time.  So in spite of the NP101's optical superiority, I think I need to live with the combo bent refractor.  I need to do a close collimation of both objectives in that scope before bringing it out.  

I tried for various new objects and observed some galaxies with the C8.

Comet 12/P Pons-Brooks was somewhere below Jupiter, which was setting fast, so I searched for it with the 4-inch but didn't notice it.  I used NV 1x and saw what I thought was a hazy area, so I pointed the scope to it and saw a bright coma with a stumpy tail pointed east, which hinted of more flowing beyond the field of view but it was very tenuous. 

Next I tried for the Procyon Nebula, but I forgot that it's rather small scale.  Using NV at 1x and 3x with Ha, I did notice a very extremely faint, mottled greyscale change primarily to the south/south-east of the main stars of Canis Minor.  This turns out to be the outer remnants of the Orion-Eradinus Super Bubble, which is a pretty cool observation by itself, but not what I was going for.  I need to try again.

The nearby Seagull Nebula was quite beautiful, and appeared as a bubble with wisps and puffs completing the arcs started by the "wings"

Next I tried some supernova remnants which were the subject of a recent paper.  These were so difficult with NV I doubt they are visual objects:

G209.9-8.2, 4-inch and Ha+OIII dual band: Appeared as a very extremely faint eyebrow of nebula to the NE of two "closer" stars.  to the south of these stars I saw a long, curved glow, heading south then east, but it quickly petered out when it curved east.  I noticed a flow of nebula passing diagonally through the view NE to SW, which seem to be the wider, fainter extensions of the nebula.  

G181.3+12.1, 4-inch and Ha+OIII, it is a new supernova remnant.  All I saw was a very extremely faint curved north rim, though there seemed a milky haze where the "inside" of the circle the arc, extended, would form.  The structure is 9-degrees in diameter and could perhaps be tried with 3x, but very doubtful.  I tried to follow the arc around its shape, but quickly lost the rim to the sky background.  I did not see G181.1+9.5, which is much smaller and on the inner eastern edge of G181.3+12.1.

Next was a series of galaxies using the C8 with NV, mostly unfiltered.  M51 was really spectacular, showing clear spiral structure with three arms, mottling, and a haze around it.  I wished to be able to magnify the view more easily (rather than unscrewing the NV).  I would have added a Powermate but the extra weight would force me to pause and try to rebalance the scopes.  NV certainly showed M51 better than my 20-inch in a dark sky, as I remember it, but the view feels not clean.  The cores of the galaxies were much brightened and bloated (as NV tends to do with bright objects).  It is like this for most galaxies -- and I miss seeing a "stellar" core which actually looks like a star.

I wasn't taking notes, just cruising around.  I moved over to Markarian's Chain and thought to do an experiment.  Using NV I was able to very clearly see both NGC 4388 and NGC 4402, two nearly edge-on galaxies which bracket M84 and M86.  Switching to glass, I could only see NGC 4388 with some difficulty (brightening averted vision) but I could not see NGC 4402.  I was using only a 22mm Nagler, so low magnification, and I might've seen it with higher magnification.  But it just points to that NV can show you more galaxies, but perhaps not as aesthetically as one would wish, and certainly not allow easy study of them for lack of image scale.

I will say NV does a very good job with faint edge-on galaxies, making them clearly visible, but again at small image scale.  NGC 4517 was very bright, it's bright core off-centered in the mottled long halo.  There were others I noticed but didn't make note of.  

I spent a fair amount of time on the Gum Nebula, which had risen fairly high.  Here is an Aladin Finkbeiner layer representation of what I saw, annotated with the major designations.  Also attached is my rough field sketch.  The "cometary" nebula is Sh2-311, and it was quite bright.  The "SC w/N" or star cluster with nebula, is RCW 19 -- in which I noticed a grouping of brighter stars which seemed like an open cluster, but I don't find a designation for one -- though large and loose NGC 2546 is nearby, and I may have thought they were together.  It would be better next time to explore this more closely with the 4- and 8-inch to capture more of the smaller structures.

Toward 1am I repeated my observation of the Spica Nebula, using 1x and 3nm Ha.  It's very satisfying to be able to have this "as my own" -- I very much doubt anyone else has seen it.

I need to do a better job planning my sessions, as I didn't remain focused.  I wandered around a bit -- Omega Centauri had risen but it was behind a tree -- it was fun to watch stars blink on and off as it moved through the sky.  Later, I watched the North America Nebula rise over a rocky ridgeline.