spring calstar

Spring Calstar was this week at Lake San Antonio.  I watched the weather carefully since it's a longish drive and a commitment to camp out for several days.  This Thursday the 16th was the most certain to be clear, with Friday a "maybe" due to some possible high clouds coming in during the night.  I packed for two nights and left around 1pm Thursday, for a traffic-free drive.  I stopped a couple times for gas and food and arrived a little before 5pm.  There were more people there than I expected all of them set-up in the baseball field.  I set-up next to Pawan along the first base line.

I brought the new-to-me 18-inch which I worked on this winter to install a Servocat and generally get working.  The movements are not smooth enough yet, and I still have some tracking and drift issues, which I hope debug in the coming weeks -- if I get frustrated enough I'll chuck the structure and buy a Telekit.  My Telrad's lens popped out so it barely functioned as a red-dot finder (since the reticule image was not enlarged by the lens) -- but luckily I had a finder scope and was able to navigate my way around.  Pointing accuracy was pretty good.   The mirror is outstanding, so I'm happy with that.

Seeing was not good and the wind didn't settle until midnight, when dew started to form.  Because I didn't think the weather would be good Friday night, I was determined to observe for as long as possible, which turned out to be 4am.  I didn't sleep well and was up by sunrise to find my telescope covered with frost!  The satellite images showed thick moisture would move in during the night, causing high thin clouds -- so after socializing for a bit I packed up around noon and went home.  I'm not set-up for a comfortable camping experience, and I don't really have the spare time to just stay the whole weekend, so going home was my best choice.

I used Alvan Huey's "Selected Small Galaxy Groups" as my project, and the below images are from that guide. I was happy to be viewing visually again, with nice small stars not bloated by NV.  The views from this darker site were about the same as using NV on my 20-inch from home, though I think I could see more finer detail and contrast if the galaxy was bright enough.

NGC 2943 group, Leo: 

8 galaxies in a 30' field.  Group WBL 229

My first observation of the night and it was a challenge!  NGC 2943 was large, bright, 2:1 elongated NW-SE, with a diffuse halo and a bright small core.  By increasing magnification from 130x to 260x I was able to see MCG+3-25-12 which was a non-stellar glow with averted vision.  Further to the east is NGC 2946, which was faint but easy to pick up, small, 3:1 nearly N-S, a mostly uniform halo with a brightening at the core.  Close to the east of NGC 2943 was NGC 2941, which was small, fairly faint, 2:1 nearly N-S with a brightened core.  NGC 2993 was small, very faint, 3:1 NE-SW, with a diffuse halo and slightly brighter core.  I did not see the CGCG-92-12, but NGC 2928 was easy, if faint, 3:1 NE-SW.

NGC 3607 Group (Leo)

7 galaxies in a 45' field.  Part of Leo II group.

NGC 3607 was a large and bright elliptical, out-of-round to NW-SE, large bright central region and small bright nucleus.  Just to SW is NGC 3605 which is a small bright glow like a broken shard from 3607.  Just to its north is NGC 3608, a smaller version of NGC 3607 but orientated E-W.  MCG+3-29-18 was easy to find as it forms an equilateral triangle with 3608 and 3607 and was a small non-stellar glow direct vision.  This triangle pointed to NGC 3599 to the west, small bright slightly elongated E-W.  To the south of the group were UGC 6296, very faint glow orientated N-S, best seen with higher magnification.  Rounding it out was MCG+3-29-24, a small faint non-stellar spot with averted vision and 260x.

IC 696 Group (Leo)

7 galaxies in a 20' field.

These were surprisingly difficult and I needed a fairly long time to observe it.  I started with IC 2853 because it was easy to find off of a bright pair of stars.  With 260x, it was faint, small, 3:2 N-S diffuse halo but unevenly illuminated to the middle, a very subtle brightening on the W and E sides of the halo, with a compact brighter core.  Its morphology is SBab, so I was picking up brighter knots in the bars!  Following the line formed but the two bright stars near IC 2853, I found IC 2850 as a small faint glow, just barely direct vision.  I then moved to IC 696, which was very faint, round, small, with a bright core which was slightly elongated (it is a face-on SBd).  IC 2857 was just to the east, a ghostly faint very long glow edge-on galaxy with a small bright core, noticed with averted vision and then can hold continuously with foveal coaxing.  To the west of these is IC 698, which was faint, fairly small, 3:1 NE-SW, and SE of it was the very small, very faint IC 2867 which was only seen averted vision.  The last member, IC 699, was to the south, and was faint, fairly large, diffuse halo 3:1 NNW-SSE with a bright core.

 

NGC 3801 Group (Leo)

6 galaxies in a 20' field.

NGC 3801 was large and bright, with a large bright core and 3:1 halo WNW-ESE.  The halo is very subtly bulkier and slightly longer on the eastern side; it is an S0/a so this might be some spiral structure.  NGC 3802 is close to its north, smaller, with a bright round core and nearly edge-on halo E-W.  And, to the north of this is NGC 3803, a small faint glow, a little larger than non-stellar.  NGC 3807 (= NGC 3806) is to the west, and was faint, fairly small, with a compact round nucleus and a faint irregularly illuminated round halo.  It is a face-on Sb.  To the east of the group is NGC 3790, small and moderately bright, brighter core in a 4:1 elongated halo NE-SW.  Lastly, MCG+3-30-35 was very faint, small, non-stellar with high magnification and averted vision, difficult. Did not see CGCG 97-46 to the north.

NGC 4005 (Leo)

12 galaxies in a 30' field.

An amazing group.  I started with NGC 4005 which was easy, bright, small 2:1 E-W with a bright core, and just SE from a magnitude 8 star.  This star is one corner of a triangle where one can locate NGC 4011 and NGC 3999, which were faint, very small non-stellar glows.  On the opposite side of the star was NGC 4000, which was faint, quite small, 5:1 N-S with a large relatively brighter region in the center and hazy tips.  Further to the NW lay three bright galaxies near a chain of stars -- I wrote "wow, wow, wow" in my log for each one, it is such a striking scene.  Easternmost in the string is NGC 3987, with a ball-like bright core pierced by a very long 5:1 halo orientated NE-SW.  Just to the NE is NGC 3993, slightly smaller than NGC 3987 but of similar appearance, orientated NW-SE.  In between these two was the very small and faint non-stellar glow of NGC 3989.  Last in this row was NGC 3997, which had a bright concentrated core and a very weak, misshapen halo NW-SE.  It is a SBbp barred spiral nearly face-on -- I detected hints of mottled structure but nothing certain.  NGC 4018 was to the NE from this string, and was a faint, very long 4:1 edge-on NNW-SSE.  The southern end of this galaxy pointed to NGC 4022, which was faint, round, small, with a bright core.  Further south, NGC 4021 formed another triangle with NGC 4023 and NGC 4015, which was the brightest of the three, all of them being small, round, on the faint side, with bright cores.  NGC 4015 is also Arp 136, as MCG+4-28-110 hags off the northern edge of the core and, seen with high magnification and averted vision, is very a very faint and small spur which points to the NE.  

To make it all the more interesting, a study in 1986 (1986ApJ...311...25W) proposed that the members of this is a rotating system of galaxies along the major axis of the group, with a period of 4 billion years!  An eddy of galaxies, having made one turn from the formation of the earth until now.  Overall, an extraordinary grouping!

M106 (CVn)

8 galaxies in a 60' field

M106 was very large, 3:1 elongated NW-SE, with a bright nucleus and very broad bright core which had slight finger-like brightenings on opposing ends -- spiral arms.  Around this was an unevenly diffuse halo which faded slowly at the edges.  Close to the NE is NGC 4248, a thin faint glow 4:1 ENE-WSW.  It pointed further east to NGC 4231 and 4232, which were closely separated faint bean shaped glows, which were tilted to towards each other.  To the north was NGV 4220, moderately large and bright, 4:1 elongated NE-SW (similar to M106's), with a bright core and tapering tips.  Back to M106 as a starting point, just to the south was UGC 7356 which I could only see by studying the star patterns on the photo and using averted vision -- it was a small, very faint puff with averted vision and 220x.  Directly to the east was yet another edge-on, NGV 4217, bright, fairly large, with a bright core and a fairly bright streak running through the halo, 5:1 NE-SW.  Perpendicular and to the south was NGC 4276, a small round glow with direct vision.

M100 (Coma Berenices)

10 Galaxies in a 60' field

M100 was pretty large and showed its spiral structure as well as I've ever seen it.  Bright round central core, there are two prominent arms, one which starts on the eastern side, is a little flattened as it comes north then sweeps east and then south.  The other starts from the north (and seems to sprout from the first arm) and is also a bit compressed as it quickly swirls to the SE then north, where it stretches quite far.  There are brighter patches in each arm, and a diffuse halo through all of it.  NGC 4323 was a very faint weak glow with higher magnification, picked up with averted vision and could briefly hold it direct.  Directly west of M100 is NGC 4328, similar to NGC 4323 I picked it up averted and held direct.  To the SW of M100 are IC 783 and 783A, two widely separated small very faint puffs seen with averted vision only -- 783A being more difficult as it was smaller, non-stellar.  South of these is NGC 4312, which is a gorgeous long edge-on, 6:1 NNE-SSW, with a bright small round core which floats on the faint halo which stretches and seems to twist at the tips.  I did not pick up the other galaxies.

NGC 5714 (Boo)

5 galaxies in a 25' field

NGC 5714 is a large bright edge-on, some 6:1 with a bright core and sharp tapering tips.  The core appears to float in the halo, which has a less-bright side, probably due to a dark lane.   To the east are four fainter, smaller galaxies, all with their own brighter core and diffuse halos of varying sizes.  Only NGC 5723 needed averted vision to pick up, though higher magnification helped to see all of them.

I also spent time picking out individual objects from the Pocket Sky Atlas, which I'll save for a different post.

24 march 2026 deepsky nv from home

Transparent sky but poorer seeing, so I decided to use the 20-inch with night vision for this session.  Logged a lot of objects, mainly from the DeepMap 600 and TAC Eye Candy list, which is actually a very good list of showpiece objects.  I was pleased with the scope's pointing accuracy even with long slews, I did something right when cleaning and reinstalling the servocat controller!

NGC 2392, stunning bipolar planetary nebula located approximately 2,870 light-years away in the constellation Gemini. Seen at small scale, it looked like a fried egg with a brighter and slightly elongated mottled center oval, and a fainter ragged loose mane.  Dual band filter showed it best.

NGC 2419 Intergalactic Wanderer, globular cluster in Lynx, 300,000 light years distant, was a puff of unresolved stars in an irregular cloud at the end of an arc of three foreground stars, with some variation in greyscale tone. 

M 67 glorious large open cluster in Cancer, with bright and faint stars scattered 

UGC 4299 08h 15m 59.0s +23°11'58" mag. 14.0b 1.8 x 0.2' Flat galaxy, very small, in the middle of two stars forming an arc, small bright core and elongated halo.  IC 2248 is nearby, round halo with a bright round core.

NGC 2353 Loose open cluster, highlighted by two oval loops of stars overlapping along their edges.

NGC 2355 Pretty, loose cluster, wedge shaped with brighter and fainter stars in middle.  Per Wikipedia it is approximately a billion years old and is located about 5,400 light years (ly) from the Solar System and 1,100 ly above the plane of the Milky Way galaxy. At that distance, the angular size of the cluster halo corresponds to a radius of about 23 ly. The core radius is 2.3 ly, and the central component radius is 11 ly.

NGC 2420 Large loose, its brighter stars look like a Hercules asterism, with a body of faint stars in the middle.  The cluster is about two billion years old, and it is located 10,000 light years away.

NGC 2683 Stunning near edge-on spiral with bright compact core and swirling arms, prominent dark lanes in the near edge.

NGC 2775 Large bright oval core and what seems a 3:1 halo.  Did not resolve the fine dark lanes and arms, through the halo was subtly mottled.

NGC 2841 Bright glowing core with very large, very extended mottled halo.  30 mly, This is the prototype for the flocculent spiral galaxy,[5] a type of spiral galaxy whose arms are patchy and discontinuous.[8] The morphological class is SAa, indicating a spiral galaxy with no central bar and very tightly-wound arms. 

NGC 2903 Bright, compact core with large halo inclined and obvious spiral arms, the one side of which has an extension which flows down and away.  Two knots on each tip outer end of the arms.  A large diffuse haze surrounds the halo.

NGC 3003 Small bright galaxy, near edge-on, the core is off-center, and with the elongated tips the galaxy appears to be curved.  

NGC 3079 Amazing long flat galaxy with halo which seems to be curved in a gentle parenthesis, as if galaxy is falling with the bright compact core being slightly heavier and the halo extended wings.  The core itself seems to be submerging into the galaxy -- perhaps due to the "bubble" with may be due to star formation triggered by particles streaming from the supermassive black hole in the center.  Did not remember to look for the twin quasar nearby.

NGC 3184 Bright, small core and very faint diffuse irregularly oval mottled halo.  Did not pick out spiral arms.

NGC 3344 bright small core, round mottled halo, an arc of three stars runs through the halo.

NGC 3384  Three galaxy group, two nearly identical with small bright core and elongated halos, and a third fainter looser spiral with faint core

NGC 3607 Two bright large ellipticals with bright cores, two smaller galaxies in the field too.

NGC 3628 Amazing long flat galaxy with a dark lane twisting through the center from end to end.  The halo is hazy and almost rectangular, making the galaxy look like a coin spun on the table.  The long diffuse tidal tail was easy direct vision.  I remember how hard Akarsh worked for this with his 18-inch at a dark site...

NGC 3675 bright core large extended near edge on mottled halo.  Did not pick out spiral arms

NGC 3877 Bright elongated galaxy, near bright star 

NGC 3941 small galaxy with a large bright core and hazy oval halo, elongated 3:1 N-S 

NGC 3115 Spindle Galaxy Sextans.  Very compact bright round core like a ball on a large, elongated halo which looks like a coin spun coming to rest with two rods protruding from each thin side 

23 march 2026

A long drought of observations due to poor weather and a busy life.  Used the 20-inch but seeing worsened through the night so I masked down to 7-inches for some doubles and stars on the red star list.  I spent a lot of time at the start of the night on Procyon and felt like I detected it with the 20-inch at 280x, but it was fleeting and more of a brightening than a hard star.  I need to get up a mountainside and out from under the marine haze.  

33 Hya: Light yellow 

56 Leo: Light yellow 

60 Cnc: Deep yellow 

BLL  27 AB: Deep red color, faint.  It is a red carbon star, and has a wide faint companion which I did not see.

08h 56m 40.14s +19° 50' 56.8" P.A. 254.00 sep 139.0 mag 8.68,12.83 Sp C dist. 1063.83 pc (3470.21 l.y.)

BSO 8 AB: Light yellow, companion with a near equal, well separated star of the same color.  Spectral class G0IV/V (yellow).  -60% PRO, it is not binary.

12h 24m 49.45s -58° 07' 10.9" P.A. 334.00 sep 4.7 mag 7.84,7.98 Sp G0IV/V dist. 173.31 pc (565.34 l.y.)

A1588 AB: 508; 380x: With 7-inch AB is elongated and faint C (BU 590 AB,C) seen widely separated with averted vision.  With 20-inch, AB is split with seeing, 1 Dm, and C is direct vision.  No Gaia data for B.  

09h 27m 14.65s -09° 13' 25.3" P.A. 196.00 sep 0.4 mag 7.79,6.95 Sp A2V dist. 234.74 pc (765.72 l.y.)

H 6 111 Yellow 

R  Leo: Brick red 

RS Cnc Pretty light orange color

 

STF1355 AB: 178; 140x: Slightly unequal yellow white stars, closely separated. 76% PRO, 105 AU WS, 1.2+1.2 Msol, it is likely binary.  SOC grade 4 orbit 1073-year period.

09h 27m 16.69s +06° 13' 59.0" P.A. 358.00 sep 1.7 mag 7.71,7.76 Sp F7V dist. 54.32 pc (177.19 l.y.)

STF1357 AB: 178; 180x: Well split, very much fainter B seen with direct vision, dull yellow A.  -3% PRO, and RVD 3.7 > 2.2 EV, it is not binary.

09h 28m 20.52s -09° 59' 12.8" P.A. 54.00 sep 7.8 mag 6.94,9.85 Sp K0 dist. 242.72 pc (791.75 l.y.)

STF1365 AB: 178; 140x: Nice white pair, 1 Dm, well split.  5% PRO but with 4.7% error, 397 AU WS, 2.0+1.7 Msol, 0.06 PMV, it probably is not binary.

09h 31m 31.26s +01° 27' 55.1" P.A. 157.00 sep 3.4 mag 7.38,7.98 Sp F9III dist. 95.69 pc (312.14 l.y.)

STF1371 AB: 178; 140x: White and 2 Dm B well split.  -87% PRO, it is not binary.

09h 35m 25.26s +03° 54' 19.4" P.A. 275.00 sep 8.3 mag 7.86,10.19 Sp G0 dist. 47.04 pc (153.44 l.y.)

8 january 2025, Procyon B with an 80mm?

Nearly a month with no observing due to stormy weather.  Last night was clear but with mediocre transparency and choppy seeing, ever with the 6-inch.  I decided to observe with the 80mm f/15 Mizar Kaiser refractor I have mounted on the 6-inch.  It is a wonderful telescope, perfect optics, and was not as affected by the seeing.  I switched between a 25mm and 10mm Plossls for low and high powers (I should have used by turret to make the change more convenient!).  

For an observing list I used Argyle's An Anthology of Visual Double Stars.  I entered all the pairs discussed in that book into a SkyTools observing list a few weeks ago.  It is a richer experience to both observe and learn more about what I'm looking at.  Unfortunately, the log function was not working on SkyTools, so I entered my observations into a notebook.  It was cold, but fortunately not dewy.  I resolved Sirius B in the 80mm while doing the 2-star alignment with the Nexus DSC.

Since I mention it in this entry's title, I'll cover Procyon B first, though I observed it at around 11pm, half an hour before I stopped.  Many people will assume more aperture is needed for challenging pairs, but I find this is not always correct.  Larger aperture has the resolving power and light grasp, but it throws out so much more diffraction on bright stars than smaller apertures the view is spoiled.  With B at a 5" separation, and at 10.8 magnitude, would 80mm still have a chance to resolve it?  As a "rule of thumb" (as discussed by Bruce MacEvoy and others), a telescope should have a star magnitude limit of +2.5 the faint unequal companion to detect it.  An 80mm's magnitude limit is only 11.5 (and assuming better conditions than I had) whereas the rule of thumb dictates a telescope which can get down to 13.3, or >178mm.  I did resolve Sirius B with the 80mm earlier in the night, which at magnitude 8.4 is within the +2.5 (8.4+2.5=10.9, <11.5 limit of 80mm).  It's worth trying 80mm, especially one of fantastic quality, to see what would happen on Procyon.  My general sense for these challenges is that one needs to find a balance: small enough aperture so the primary's diffraction is not over-powering, but large enough to detect the companion.  

I first observed Rigel A-BC, which has a 9" separation, to get a sense of the distance 5" would be (slightly less than half).  I then observed Procyon, which presented a slightly wavering airy disk and several round concentric diffraction rings.  The transparency caused a haze to appear within and around the rings.  I saw three fainter, wider stars near to the primary.  Using 267x I had a sense of a star trying to resolve within that haze but was not certain.  I then used a 9mm orthoscopic eyepiece which has a crosshair installed, 297x.  I was able to hide the primary behind one line of the crosshair (and I impressed myself being able to do so, and the steady tracking of the mount!).  It neatly covered the primary and only the diffraction ring and haze appeared.  In better moments a small mass appeared to the north (the correct PA) and at roughly the correct separation.  It was trying very hard to resolve to a star, and I think maybe it would have if the transparency was better.  It moved with the scope and was steady in the same location no matter where I moved it in the field, so I am fairly certain it is not a reflection or an aberration.  Unfortunately, I could see no such mass in the 6-inch telescope (which is not as great optically, and the seeing threw up too much diffraction). As exciting as this was, I don't count this as a confirmed observation, it's too marginal.  I should have tried a hexagonal mask, and maybe some filters.  I long for the "no doubt about it" clean clear view, and I plan to take this and larger apertures up to one of our local mountaintops when seeing and transparency are better to make this observation again.

STF 774 AB: AC seen with 80mm at 48x, faint but solid.  AB is elongated at 80mm at 120x.  In the 6-inch at 180x, AB is split in poor seeing.  AB with a SOC grade 4 orbit, 5587-year period, and will not move much for the next couple of hundred years. Gaia parallax data is missing. 

AC: 05h 40m 45.52s -01° 56' 33.3" P.A. 10.00 sep 57.6 mag 1.88,9.55 Sp +A? dist. 225.73 pc (736.33 l.y.)

AB: 05h 40m 45.52s -01° 56' 33.3" P.A. 167.00 sep 2.5 mag 1.88,3.70 Sp +B0III dist. 225.73 pc (736.33 l.y.)

STF 900 AB: 80; 48x: Lovely wide white and 2 Dm B, which is bluish. No parallax range overlap, -26% it is not binary.  A Herschel discovery.

06h 23m 46.10s +04° 35' 34.2" P.A. 29.00 sep 12.1 mag 4.42,6.64 Sp A5IV+F5V dist. 37.5 pc (122.32 l.y.)

STF 919 BC: 80; 140x: Beta Mon. BC is elongated in the 80mm at 48x, split nicely with 140x, yellow-white stars, C fainter by a half magnitude.  It provides a nice surprise for the observer, to bump up magnification a bit and "discover" a double.  Argyle relates how Castelli discovered it by borrowing a telescope from Galileo in 1617.  And with the wider A star, which is half a magnitude brighter than B, it forms a small arc.  Herschel called it "one of the most beautiful sights in the heavens; but requires a fine evening."  There is only Gaia parallax data for A and C, but the two of those together have 77% parallax range overlap, 2,092 AU weighted separation, making a strong case they are gravitationally bound.

06h 28m 49.07s -07° 01' 59.0" P.A. 132.00 sep 7.3 mag 4.62,5.00 Sp B4V+B2V dist. 207.47 pc (676.77 l.y.)

STF 950 AB: 80; 48x: Bright star and its 3 Dm faint wide companion sitting in the middle of a large, sparse open cluster (NGC 2264, Christmas Tree cluster).  18 different components measured over the years.  Argyle says the primary is "thought to be the source of a bubble of hot gas which influences the kinematic properties of the surrounding gas and stars."  No nebulosity seen!  -15% PRO, it is not likely binary.

06h 40m 58.66s +09° 53' 44.7" P.A. 214.00 sep 3.0 mag 4.66,7.79 Sp O7V+B1.5V dist. 281.69 pc (918.87 l.y.)

STF 948 AB: 80; 140x: At first I saw a wide 2 Dm pair at 48x, and the primary did not appear round, so I increased power to 140x and had a hairline split, slight delta magnitude.  It is a wonderful 2+1 system.  AB has -3% parallax range, so it's a toss-up if it's binary.  SOC grade 4 orbit, 733-year period.  It was a Herschel discovery.  

06h 46m 14.15s +59° 26' 30.1" P.A. 64.00 sep 1.9 mag 5.44,6.00 Sp A3V+A1IV dist. 65.83 pc (214.74 l.y.)

STF 982 AB: 80; 140x: Best view between either scope was 80mm at 140x.  Well split 2 Dm, yellow-white and yellow-orange.  No Gaia parallax for the primary, though there is a SOC grade 4 orbit 1749-year period.

06h 54m 38.63s +13° 10' 40.1" P.A. 142.00 sep 7.4 mag 4.75,7.80 Sp F0Vp dist. 25.63 pc (83.61 l.y.)

HJ 3945 AB: 80; 48x: Orange and blue, wide pair, very Albireo-esque (it's nicknamed the "Winter Albireo").  -83% PRO, it is not binary.  

07h 16m 36.84s -23° 18' 56.1" P.A. 50.00 sep 26.5 mag 5.00,5.84 Sp K3Ib+dF0 dist. 434.78 pc (1418.25 l.y.)

STF 1066 AB: 80; 140x: Wasat. Excellent pair, pale yellow-orange A and very faint B outside A's diffraction ring, a very fine point.  Discovered by Herschel the same night he discovered Uranus!  45% PRO, 108 AU WS, 1.9+0.7 Msol, but with a -0.25 proper motion vector -- I wonder because its orbit is taking it in the opposite direction?      The orbit does predict a rapid swing from west to east, which is consistent with that -- so proper motion is sometimes not a good indicator of binarity.  SOC grade 5 orbit 1418-year period.  Another Herschel discovery.

07h 20m 07.39s +21° 58' 56.4" P.A. 229.00 sep 5.5 mag 3.55,8.18 Sp F2V+K6V dist. 18.54 pc (60.48 l.y.)

STF 1110 AB: 80; 48x: Castor. Bright unequal white pair, with 2 fainter wide stars nearby.  SOC grade 3 orbit, 459-year period.  Argyle: "It was used by William Herschel in 1803 to demonstrate that pairs of stars are genuinely connected by a mutual force of gravity."  

07h 34m 35.86s +31° 53' 17.8" P.A. 51.00 sep 5.4 mag 1.93,2.97 Sp A1V+A4Vm dist. 15.6 pc (50.89 l.y.)

STF 1196 AB: 80; 140x: Zeta Cnc.  Lovely close pair, nearly 2 Dm, split at both 48x and 140x, including the C pair.  Flamsteed discovered the AB-C pair in 1680, Herschel the AB in 1781.

08h 12m 12.79s +17° 38' 51.2" P.A. 349.00 sep 1.1 mag 5.30,6.25 Sp F8V dist. 25.08 pc (81.81 l.y.)

STF 1268 AB: 80; 48x: Iota Cnc.  Gold and blue, wide, lovely.  Discovered first by Mayer in 1777, then Herschel in 1782.  Might not be binary due to parallax difference.

STF 1321 AB: 80; 48x: Faint, equal pair, wide.  7.79/7.88, 14".  Tentative orbit published, and both stars might be exoplanet hosts.

STF 1334 AB: 80; 140x: !! Very fine close split, large delta.  A Herschel discovery.  3.92/6.09 2.6"

STF 1424 AB: 80; 140x: Orange 2 Dm, good split.  Herschel discovery.  2.37/3.64 4.7".  

11 december 2025, random nebula from the peak

Had a nice opportunity to go out observing this new moon cycle to Fremont Peak Thursday night.  The 2600' elevation was above the inversion layer which has been holding cold air, and poor seeing and haze, in the Bay Area.  It was indeed warm and dry all night, not a trace of dew.  Seeing was ok but not great.  I set-up on the pads next to Peter N. and Dave C., both of whom I haven't seen since a CalStar a couple years ago.  Peter had a 16-inch dob and I suggested we try Mira later in the night, but when Peter tried, he knew seeing would not be up for such a difficult observation.  SQML was 20.5 according to Dave, not great but OK for me.

I brought my 10-inch f/3.7 Swayze and night vision.  I didn't have a particular plan, other than to observe various large objects with this scope, which I don't recall having out in the winter.  I searched around in Interstallarium searching for nebula.  I observed exclusively with the PVS-14 afocally with the 67mm plossl, with a 2.5º TFOV.

NGC 1491: Sh2-206, aka "The Fossil Footprint Nebula," is an emission type bright nebula located about 9,800 light years away in Perseus.  It is an older, evolved HII region ionized by the O5 star BD +50 886.  It was discovered by William Herschel.  With 3nm Ha there was a very bright central milky knot mottled heavily with dusty-looking haze, and a sharp cut-off on the west side.  The mottled nebulosity rippled away from this central area and diffused to the east, and with some bright semi-arc streaks mixed in with fainter dusty haze.  Later in the night I observed this region with the NV device handheld with an Ha filter, and this nebula seemed to form the apex of a long stream of very faint nebulosity running south parallel to Perseus, forming a sort of cape.

vdB 14 & 15: Part of the van den Bergh catalog of bright reflection nebulae, located in Camelopardalis, and circumpolar. They are faint bluish reflection nebula created as starlight from nearby bright stars scatters off interstellar dust.  Nicknamed "The Space Waterfall" by astrophotographers.  vdB 14 is a faint, dusty looking mottled elongated glow, with some sinuous seams flowing its length, its illuminating star off to one side, like a mini California Nebula.  vdB 15 was an irregularly round glow around a bright star, with diffuse edges. 

NGC 1333: Embryo Nebula.  In my notes I wrote "this looks like a beetle."  The "head" is mostly round with edges nibbled with dark nebula, with two pillar like formations.  There is a prominent dark intrusion which helps separate the head from the rest of the body.  The body has bright rims or ridges of brighter sections which are denser areas facing stellar winds. It is bisected lengthwise (the "suture") with darker mottling, and there are also crusted with dark nebula. According to the internet, the nebula is primarily composed of molecular hydrogen, dust, and ionized gases. Ultraviolet radiation emitted by nearby young, massive stars causes surrounding gas to glow and forms intricate filaments, knots, and cavities in the nebula.

 

NGC 663: The "Letter 5" nebula, which can be seen as an asterism of some of the brighter stars in the large, fairly loose, and rich cluster.  There is a central round region of fainter stars, with arc of moderately brighter surrounding it. 

NGC 1624 = Sh2-212: Small sparse open cluster surrounded by a bright but hazy, dusty glow.  Brighter to the middle and diffuse edges, mottled and streaked with dark nebula, looks to me like a lion's mane.  

PN IPHASX J055226.2+323724 in the open cluster M37.  Discovered in 2022, the PN in M37 is the third known planetary nebula associated with an open cluster, and it has been determined to have a kinematic age of 70,000 years. This age is based on the nebula's expansion rate, which is consistent with the properties of the host star. I first tried to observe it a couple of years ago in Mark Wagner's 18-inch telescope with night vision but could not convince myself I saw it then.  This time, after a few minutes observing, I noticed a very faint oval glow in the correct area of the nebule (northern edge).  In my field sketch I roughly drew the cluster and in particular three brighter stars on the periphery which were just to the side of the faint glow I saw, which I drew and pointed and wrote "here?" for me to follow up later.  Now that I have the discovery image below, I can confirm I did indeed see the nebula, nearly to its fullest extent (minus the very faint wisps trailing away from the cluster).

B33 Horsehead Nebula: Everyone with NV will look at the Horsehead, since such a difficult object is so easily seen with the device.  I observed it with 1x, just holding the device without a telescope, as a dark intrusion into the nebula.  At 3x, with a lens attached to the front of the device, I can see the direction of the snout.  With the 10-inch scope, I saw the bump on the horse's head, the protrusion of the snout, the rim of bright nebula running along the top of the head, and even the trail of dark nebula which would be the mane of the neck, but it's separated by a very thin strip of brighter nebula.  IC 434, the bright nebula, forms a bright, sinuous line not unlike some portions of the Veil Nebula (i.e. the Witch's Broom), and huge sheets of the bright nebula seem to evaporate off this line into the sky.  

Sh2-261: Lower's Nebula.  According to the internet, H. A. Lower discovered this nebula in 1939 by using an 8-inch f/1 Schmidt camera with Agfa Superpan Press film and exposure time of 20 minutes.  An emission nebula with both Hb and OIII emissions, it showed up well in my Tri-band filter (Ha, Hb, OIII).  The dark central region is lined with irregular streaks and patches of nebulosity, brighter on the southern side.  The southern side is smaller than the northern, which is turbulent and diffuses slowly in a great arc which trails to the east.  The western edge has a very faint pointed stream of nebulosity which looks like a break-out from a planetary nebula.  A great amount of detail in this large nebula which nearly filled the field of view.

Abell 12: Appeared as a tiny thick, smooth-edged ringed planetary with a soft milky middle next to bright star Mu Orionis.  Did not have enough magnification to notice the breakout along the northern edge.

M1: Best seen through the dual band filter (Ha+OIII).  Hairy oval shape, heavily mottled, with two round bright loops in nearly complete intersecting circles.  I'd love to view this with a larger scope with more image scale.

Abell 21 Medusa Nebula: Bright dome shape with a fairly crisp upper edge and two trailing "legs" on either side.  The center is filled with milky nebula, and the very faint breakout nebula can be seen flowing away opposite from the dome.

NGC 2261 Hubble's Variable Nebula looked like a small squat comet with a broad fan-shaped tail.  One edge of the tail was like a bright small spike, and the other was a bright, longer streak which curved back behind the nebula.  In between these sides was filled with subtle greyscale changes of bright nebula, suggesting structure even in the tail.  Wish I could have used more magnification.

Sh2-310: Large wash of nebula floating near open cluster NGC 2362.  According to Wikipedia t is one of the largest H II regions known in the Milky Way and us ionized by the stars Tau Canis Majoris and UW Canis Majoris. What I was looking at in the scope was the brightest patch of this giant cloud.  Its entire extent is best seen with the NV device handheld at 1x, where it forms a kind of tail to Canis Major.  I also noticed faint streams of nebula which linked it to the Seagull Nebula -- of which most are familiar with the brightest part forming the Seagull shape, but don't see the bubble the wings form unless using low power NV.  Here is the Finkbeiner image from Aladin to illustrate.

Planetary Nebula FR 2-25.  For a full description and a wonderful image of this object, go to Jon Talbot's Astrobin page here.  I noticed this on my atlas and gave it a try, using my Nexus DSC with the Ra & Dec entered to find the general area.  After at least 10 minutes of careful observation, I noticed an extremely faint small glow arcing away from a string of four faint stars (an arc of brighter stars was to the SE).  My notes are "vague cloudiness here in the right spot" with a sketch of the curve and the star field.  A pretty difficult observation but worth the effort!

NGC 2403: According to Wikipedia, this is an intermediate spiral galaxy in the constellation Camelopardalis. It is an outlying member of the M81 Group and is approximately 8 million light-years distant.  In the scope it was small and fairly bright, with a bright quasi-stellar nucleus, and a heavily mottled 3:1 halo, with two arms visible on each side looping inside the halo.  

NGC 4236: Appeared very faint, at the edge of perception, unfiltered as a small cloudy elongated contrast change.  NV is not always good for galaxies. Per Wikipedia, it is a barred Magellanic spiral galaxy located in the constellation Draco.  The galaxy is a member of the M81 Group, a group of galaxies located at a distance of approximately 11.7 Mly (3.6 Mpc) from Earth.

As Peter and Dave packed up at around 12:30am, Peter pointed out he could see Kemble's Cascade naked eye and gave us the instructions to look.  It was at zenith, and one started from Perseus' "head" and looked east several degrees for a line of stars.  Really nice to see it this way.

9 december 2025

First observing in a month!  We've had a high-pressure system locked in over the Bay Area for weeks.  It created an inversion at around 1500' and has locked in haze and fog over all the valleys, so it has not seemed worth going out.  The inversion also creates a layer of turbulent air, so while seeing might be predicted as good, it is usually a seething mess. 

I also had a malfunction of my ServoCAT on the 20-inch.  I searched and found another Gen2 set to replace it, and finally tried using it over the last few days.  It turns out (having re-read the instructions), when I replaced the azimuth encoder, I accidentally flipped a control switch on my original unit to incorrect position -- one which turns the motors off!  I put my original unit back in place and used it last night -- it worked fine.  And my pointing accuracy was pretty good too.

Mira is at minimum, though I missed the window slightly as it is brightening from it's mag 8.5 low.  I tried desperately to see JOY 1, currently 0.4" per the SOC grade 4 orbit (due east).  I could not see any companion at any power, but I did get a strong sense of an elongation.  The seeing was just too poor.  This pair will close in the coming years, so really now and maybe next minimum is my only chance.  I'm planning to go to Fremont Peak this new moon, to get above the inversion layer and hopefully borrow someone else's telescope -- or use the 18-inch dob I got recently, once I have the new ServoCAT installed on it.  Must work on that project urgently!

I continued observing other pairs but masked down mostly due to the seeing.  It felt good to have the old girl running again.

BU    8 AB: 203; 280x: Very close, subtle split, large delta.  No Gaia data for the secondary.

02h 21m 22.11s +08° 52' 50.6" P.A. 224.00 sep 1.6 mag 8.03,9.20 Sp F0 dist. 120.34 pc (392.55 l.y.)

BU  506 AB: 508; 560x: A solid fleck of a star, fairly well separated, with seeing in A's diffraction.  A is light yellow orange.  No Gaia data for the secondary.  SOC grade 5 orbit 850-year period.

01h 31m 28.99s +15° 20' 45.0" P.A. 62.00 sep 0.6 mag 3.83,7.51 Sp G8III dist. 107.18 pc (349.62 l.y.)

KUI  8 AB: 203; 560x: Unequal overlapping disks all powers.  Need slightly more aperture.  No Gaia parallax data.  SOC grade 4 orbit, 653-year period, little change the next few decades.

02h 27m 59.93s +01° 57' 39.1" P.A. 40.00 sep 0.5 mag 7.09,7.63 Sp K0III dist. 166.67 pc (543.68 l.y.)

STF 231 AB: 203; 140x: Pretty pastel yellow and light blue, 1 Dm, wide. Bedford Catalog, "pale yellow...sapphire blue."  -18% PRO, it is not likely binary.

02h 12m 47.54s -02° 23' 37.1" P.A. 235.00 sep 16.8 mag 5.72,7.71 Sp F8V+G1V dist. 39.7 pc (129.5 l.y.)

STF 239 AB: 203; 140x: Part of a large loose group of stars but is not an open cluster, unequal white wide. Bedford Catalog, "silvery white."  -7% PRO, it is not likely binary.

02h 17m 25.29s +28° 44' 42.1" P.A. 212.00 sep 14.0 mag 7.09,7.83 Sp F7V+F9V dist. 34.52 pc (112.6 l.y.)

STF 271 AB: 203; 140x: White A and wide 3 Dm B.  Bedford Catalog.  Lacks Gaia parallax data.  

02h 30m 32.31s +25° 14' 06.8" P.A. 184.00 sep 13.0 mag 5.93,9.94 Sp F6IV dist. 51.76 pc (168.84 l.y.)

STG   2 AB: 203; 140x: Bright light green A, B not seen. Bedford Catalog, A pale orange and B cinereous ("especially of feathers, light grey").  No shared parallax, it is not binary.

02h 44m 56.54s +10° 06' 50.9" P.A. 344.00 sep 158.4 mag 4.20,13.60 Sp F0IV dist. 25.77 pc (84.06 l.y.)

STT  45 AB: 203; 280x: Very close split, white, with seeing only.  Lacks Gaia data.  SOC grade 5 orbit 1207-year period.

02h 40m 56.61s +04° 52' 14.6" P.A. 256.00 sep 0.8 mag 7.39,8.95 Sp F0

STT  47 AB: 203; 140x: Bright A has almost a greenish blue tint, and foveal coaxing reveals two faint stars not far off forming equatorial triangle.  Nice scene.  Lacks Gaia data.

02h 49m 59.03s +27° 15' 37.8" P.A. 296.00 sep 34.7 mag 3.63,11.04 Sp B8Vn dist. 50.79 pc (165.68 l.y.)