Tuesday, September 27, 2016

close doubles in equuleus

Last night's observing was a very satisfying.  It was a very hot day, in the low 100s, and only cooled a little during the night -- I wore shorts and a t-shirt.  A wildfire broke out at Loma Prieta during the afternoon, and looked like an erupting volcano, sending dark smoke in a thick column into the sky.  My regrets for those who lost property or were in the smoke.  Selfishly, as for my observing, the onshore winds kept the smoke to the south.  Transparency was very good and seeing improved to very good by 10pm.

I started out looking at Saturn, for a likely last long look at the beauty for this year.  It held up ok at 277x but was a little low.  The seeing at the low altitude and above the neighbors' roofs was rougher, but every once in a while Saturn would snap to sharp focus, showing the Cassini Division, color gradations in the rest of the rings, and four of its moons spun out from the plane of the rings.  I moved the scope to the east for a look at Mars, which was positively gibbous, and showed some markings.  I realized Mars was moving in front of the central region of the Milky Way, so I switched to low power (71x 1.1°) and slowly swept side to side, then raising up one degree at each sweep.  Many faint stars and a lot of faint cloudiness.  I noticed a faint nebula and put in an OIII filter; M8 revealed itself, including the bright Hourglass nebula, the dark lane, and the scatterings of open cluster stars.  Further up I came upon the Sagittarius Star Cloud, filled with stars of differing magnitudes and colors.  The edges of the field were dark and wispy: the smoke of creation wafted aside to reveal the rich star fields of the center of our galaxy.  It was beautiful.

After 9pm I set to work surveying the doubles in Equuleus.  I viewed the ones plotted in the CDSA and a list of close doubles I prepared beforehand.  I was especially pleased with HO 151, as I relate in my notes:  All at 553x, Pickering 7:

STF 2765 AB: Well split, equal magnitude, orange pair.  [8.47/8.50, 2.8"]

7 Equ / Delta Equ / STT 535 AB:  Too bright, too many diffraction rings.  Not much hope of seeing this except as an egg.  [5.19/5.52, 0.1"]

5 Equ / Gamma Equ / KNT 5 AB: Not seen; only a disk with surrounding diffraction rings. [4.7/8.69, 1.0"]

BU 163 AB: Close but definite split when seeing stills and the diffraction rings disappear.  [7.31/8.88, 0.9"]

STF 2786 AB: Easy; near equal white.  Two other fainter, widely separated above and below the pair, part of the system? [No.  7.49/8.2, 2.7"]

S 781: Very wide bright white, similar magnitude; well separated in 50mm finder.  [Should have looked this up beforehand.  AB is 7.42/9.4, 0.6" -- probably not possible with my aperture.  The AB,D set is 7.25/7.17 186.1" and likely what I saw.  There is a AB,C set 7.25/14.01 31.1", which I did not see probably due to the C's faintness.  A very interesting set.]

STF 2742: easy wide, equal brightness pair.  [7.41/7.64, 2.9"]

1 Equ / Epsilon Equ / STF 2737 AB: Strongly feel an oval AB pairing, but not quite certain.  C is below the main pair.  [AB is 5.96/6.31 0.2" -- detecting an oval or egg would be very difficult.  There are three additional pairings to AB in this complex multiple system.]

STF 2735: Pretty gold and blue; close but well separated.  [6.45/7.54, 2.0"]

STF 2744: Close, equal magnitude, bright yellow-white.  [AB 6.76/7.33 1.2" and is what I saw.  There is also an AC and AD, 12.9 and 14.3, 97.8" and 73.9" respectively, which I did not see.]

Howe 15: Orange; nothing close to it; a wide faint blue.  [Does not pop up on Stelle Doppie.  CDSA says it is 6.1/9.8, 26", consistent with what I saw.]

HO 151: !! Very faint, hazy unresolved patch which, when the seeing stills, is pierced by two small pinpoints; very firm, close but separated.  Both stars bluish.  Lies to the south of a brighter orange star.  I'm so thrilled to see these appear out of the murk.  [9.67/10.02, 1.5"]

STF 2791: Did not see.  It is another close faint pair [8.92/9.28, 2.9"]

BU 838: Not seen.  [7.92/10.02, 1.6"]

Anonymous plotted 5 minutes east of STF 2787: Brighter A, dim B widely separated to the north, another further away to the west.  Checked the Carro catalog, can't find a likely listing at this position.

STF 2787: Bright A and bluish B, wide separation.  [AB 7.49/8.64, 22.4".  There is an AC pair, 11.41, 70.7", not seen]

Since it was closeby I moved the telescope over to M2.  I remembered how hard I needed to work to star hop to it when I first got my telescope a couple years ago.  Now it was easy.  It was bright, and large in the field, resolved stars throughout with a grainy grey background, misty shoots and clumps of stars.  A very nice way to end the session.

Friday, September 23, 2016

the moon this early morning

I have become more motivated to observe the moon, in a more diligent way.  I came across a "Lunar 100" list by Charles Wood, and decided to complete the list as an observational project.  The list includes a table of the best age of the moon to observe each feature, and almost all of them have two days, the beginning of the moon's cycle and later in the cycle -- meaning the "best" times to observe are at differing angles of light.  So the "100" has become a list of 195 separate observations.  It will be interesting to see the effects of the light angles.  I'm looking forward to getting to know the moon better.

Yesterday I looked up the chart pages in the Hatfield and the Rukl atlases, but did not complete integrating those with the list.  So, I did not have a list prepared for my session.  No matter.  Since the moon is third quarter now I decided to wake up at 4:30am, as it was predicted to be clear.  I woke at 3am but couldn't fall back to sleep, so I went outside a little after 4am.  Orion was arching over the meridian tree, and I could even see the lower shield stars despite the moonlight.  Other familiar shapes appeared: Pleiades, Hyades, Auriga, and Gemini.  I rolled the shed back from the 12.5-inch and set-up, then pointed it up to the moon -- which was hidden by the apricot tree!  I went back inside and brought out my 8-inch f/7.25 and set it up in the moonlight, so I could observe a while as the moon cleared the tree for the 12-inch.

The 8-inch mirror was still warm and took about 20 minutes to equilibrate.  I spent a fair amount of time along the terminator, and in general all around the moon, at 227x.  I really need to clean my barlow; three dust specs appeared as dark mare features on the moon.  The Montes Alpes had scattered bright peaks and grainy, rubbly slopes.  Mons Piton cast a fairly long shadow.  The feature I described as the square on the moon -- actually a rectangle -- turns out to be the well known feature Aristarchus Plateau.

After a half hour and a cup of coffee (which I prepared before bed and put in a thermos), I moved back to the 12.5-inch and found the moon had finally cleared the tree.  The view through this scope was much more finely resolved, as to be expected, and it was nice to have it tracking the sky.  I spent a fair amount of time studying Arzachel, which has high crater wall ramparts, terracing, a central peak, round craters of various sizes, and a rille winding through it.  A very interesting crater.  Mons Piton's shadow was appreciably longer -- I'm certain due to the passage of time rather than just the larger scope and higher magnification (340x now).  Pluto's craterlets were out of reach but there will be more nights.  Well before I expected it dawn started.  The highway traffic noise was louder, a couple neighbors had switched on the lights in their kitchens, and only the brightest stars in Orion shown in the lightening blue sky.  Our own kitchen light switched on and I knew then it was time to step inside.

I felt happy driving into work, having indulged my hobby before going in to the job.  I'm drowsy now but I don't mind.  It's supposed to be clear all tonight, so perhaps I'll get up early again.  I'll have to use the 8-inch though since the moon won't clear the apricot tree again this morning.  Maybe I'll even steal a peek at the Orion Nebula before I blind myself on the moon.

Thursday, September 15, 2016

square on the moon, part 2

I reobserved the marble green square area on the moon again last night.  At low power (71x) it was still distinct from the brighter area but not quite as dark as it was the night before, likely from a change in the light angle (93% illuminated).  Seeing was very good, so I ramped up power to 277x then 553x. The color change making the square was still very apparent, but there was a lot more fine detail to observe too, and I could see the delineation between the color changes was not as sharp as at low power.

Starting from Aristarchus: This crater has a bright wedge shaped ejecta field streaming toward Herodotus; these two craters take a corner off of the square.  The darker area continues to Schiaparelli then takes a nearly right angle turn following Dorsa Burnet to Humason.  The next turn seems to be at Nielsen and then back up to Aristarchus, with Rupes Toscanelli as the divider.

What was very interesting was a ghost crater (or is it called shadow crater?) which was a very old formation filled in with lava which had subsequently been deformed by later, smaller crater impacts.  I could trace the sunken, faint round outline from Schiaparelli to below Montes Agricola and into that field.  I don't find this traced on Rukl.  Careful attention rewards the time and effort spent observing.

After only 40 minutes observing the moon went behind the meridian tree.  I used my 7x35 binoculars for a while and was able to pick out some Messier objects despite the light pollution and nearly full moon: M31, M11, M13.  Also the Coathanger and the lovely star fields of Cassiopeia.  The sky around Delphinus and Sagitta was grainy, faint Milky Way stars wishing to be seen.  New moon is coming up, I will have my chance.

Tuesday, September 13, 2016

square on the moon

Just in from a very short session, but I want to get it down while it's fresh in my mind.

While observing with the 12.5-inch, using 71x and the moon filter, from 4:00 to 4:30 UT, I noticed a distinct square on the moon, a little foreshortened by the curve of the moon, but it was there.  It was a relatively dark color, marble green.  It was as if there was a piece of square tape on the moon, left for a long time -- while the moon collected dust the part underneath the tape stayed clean -- then someone removed the tape leaving this clean green square on the moon.  It must have been a trick of the light (waxing gibbous, 86% illuminated).

The square started at Aristarchus and went to Schiaparelli; then turned at a right angle to Humason; then another right angle to Krieger, then back up to Aristarchus.  A corner of the square was bitten off by Aristarchus and Herodotus, which were still bright, but everywhere else within this boundary was a marble green, contrasted with the rest of the brighter surface.

I see on Rukl there are wrinkle ridges and mountains along the boundary line (Dorsa Burnet, some unnamed, and Rupes Toscanelli) -- somehow these define the boundary, either a change in elevation, or some blockage of light.  The square area is much more rugged than the surrounding area, suggesting it may night reflect as much light back and so appears darker.

It's a very surprising and unique sight.  I'm in early just to write this down but also because the moon went behind the meridian tree and the marine layer started coming in.  I hope it is clear tomorrow, I'll see whether the feature is still there.

Friday, September 9, 2016

more close doubles in aquila

I tried again last night for more close doubles in Aquila in the 12.5-inch.  These were not plotted in CDSA, being either too close or having too wide a magnitude difference between the pairs.  Seeing was perhaps Pickering 6-7, not really good.  I found some and missed some:

BU 265: Yes!  After quite a while of staring and focussing.  Very faint but resolved B at outer diffraction ring when seeing stills.  Yellow A, bluish B.  [7.37, 9.24; 1.4"; 1698 ly].

STF 2408:  A star resolves but is hazy.  There is an airy disk flashing out in the middle of the haze where B is.  [8.47, 9.38; 2.3"].  I wonder if the haze is due to its faintness, poor seeing, or if there is nebulosity in the area?

D 20: Didn't see AB pair (which is 9.58 1.3") despite the tight airy disk of A; but I do see faint star much further out which should be the C pair [AC 7.22, 10.51; 24.6"].  Very near to a pretty orange carbon star.

I tried another few (KUI 91, HU 72, BU 976) but could not make any of the pairs.  There was a thin fog blowing in from the ocean which interfered with seeing fainter stars.  The moon was getting too low to observe well so I packed it in early at 10:15pm




Thursday, September 8, 2016

close doubles in aquila

Clear Sky Clock predicted excellent seeing for last night, so I prepared a list of close doubles in Aquila for the night's observation.  Most were <2" separation and about half of the 25 were plotted on the CSDA, and those were the ones I observed.  Seeing is to be good tonight too, so I am printing finders for those not plotted in the atlas.  I used the 12.5-inch at 553x throughout.  I started at 9pm when seeing was good but not great, yet still had nice airy disks.  By 10pm it was very good and by 10:30pm it was fantastic, but that was when I needed to pack in.  "Wide" in my descriptions refer to the easy by which they were separated.  Some of the C pairings were missed because they weren't on the list, being wider than my cut-off criteria:

STF 2404, well split, yellow A and yellow-orange B.  [6.92, 7.77; 3.6"]

STT 368 AB: Definite split, 1/2 an airy disk width; near equal brightness.  Did not notice AC  [7.53, 8.49; 1.1"]

23 Aql AB: Pretty wide separation, just a large difference in magnitudes.  A bright orange, B bluish. [5.28, 8.29; 3.2]  Faint star much further out was the AC, 13th mag 10".

STF 2545 AB: Easy, wide separation yellow and orange.  [6.79, 8.54; 3.8"].  Did not notice C pairing.

AC 12: [Alvin Clark!]: Pretty wide separation, about 1 magnitude difference.  [7.54, 8.32; 1.5"]

52 / Pi Aql / STF 2583 AB: Very definite split.  A mini Alberio, gold and blue.  [6.34, 6.75; 1.5"]  Did not see AC pair.

STF 2596: Definite clear split, 2 airy disk widths.  (High on the ladder, hanging over to see; drive on the equatorial platform ran out!).  [7.29, 8.68; 2"]

HI 93: Easy, fairly wide separation.  [7.67, 8.39; 1.8"]

Anonymous ~ 2 minutes east of STF 2654: Bright A and faint B, ~2.5" separation.  Very nice.

65, Theta Aql: listed as having an Ab and Ac, with 1" separation, but nothing was seen.  Surely an error, or spectroscopic only -- no magnitude given for the 1" pair.

STF 2644: Nice near equal pair, wide separation.  [6.92, 7.06; 2.5"]

STF 2643: White and reddish stars, wide separation, large magnitude difference.  [8.17, 9.23; 13.8"]

STF 2651 AB: Very close but clear split, equal brightness white stars.  In a rich field.  This wasn't plotted in CDSA so I swept the area to find; I feel the thrill of discovery.  Beautiful sight.  Seeing is very calm.  Great way to end the session.  Too bad I need to go in.  [8.41, 8.44; 1.0"]

Wednesday, September 7, 2016

impressions

Was out last night with the 12-inch, but mainly wandered and gazed rather than observed.  As a result I have a set of impressions rather than observations:

The Moon:
Far detached peaks at sunrise -- first flash of dawn
The grey round mass of the unlit moon: perfect grey-black sphere, closing in on a star
Mountain ridge looks like a gecko missing its tail
Dark craterlets, sinuous crater rims
Ghost craters in the shallow seas, like ripples on smooth water
Wrinkle ridges, the moon showing its age
Fans of ejecta

Mars: Syrtis Major jutting down like India

Sweeping for doubles in Aquilla:
Faint close triple, same magnitude, a triangle with equal sides
Many faint double pairs
Teal blue pair, equal, about 9th magnitude, 3" separation -- lovely pair of eyes

Tuesday, September 6, 2016

pinnacles

Sunday night joined Jamie Dillon at the Pinnacles National Park at the Chaparral Trailhead parking lot, beneath the hoodoos.  While driving above Soledad on Route 149 I noticed smoke from the Soberanes fire in the mountains to the west.  The winds from the north / north-northwest blew it away from the Pinnacles.  We had an impromptu star party for some hikers who came to the parking lot after dark – they said they got a little lost on the trails and were relieved to make it back.  After turning off their flashlights they enjoyed the starry sky; two of them lay down on the pavement, to both rest and take in the Milky Way.

Seeing was not great in the beginning of the night, but it got better.  I estimated Pickering 6 by 10pm and 7 after 11pm, and I daresay up to 8 after 1am.  Transparency was merely good; minor dewing persisted through the night.  It was surprisingly cold, low 40s at midnight dipping into the upper 30s very late –along with the rise of the Hyades, it was a herald of the approaching winter.  I should have just taken the best near zenith, but the tyranny of my lists drove me to Sagittarius and environs.  Toward 2:00am Jamie was able to make out the Gengenschein just below and to the east of the Circlet in Pisces.  I could not discern it despite Jamie’s careful description; I have never seen it and didn’t know quite what to see.  Here are some other highlights, all in my 20-inch reflector:

NGC 6620, PN in Sgr, 12.7v, 5.3” x 3.8”: @ 205x a small bright disk, bluish grey unfiltered, more strongly blue-green with OIII.  Soft but consistently round rim; no central star. 

NGC 6629, PN in Sgr, 11.3v, 16” x 14”: @ 205x it appears as a smallish hazy disk with a bright central star.  Has a ragged blue-green outer shell [others report seeing sharp edges, so my view may have been distorted by poor seeing].  Very dense field.

IC 4732, PN in Sgr, 12.1v, 3”: @205x, small and faint somewhat bloated star in line with two other brighter stars.  OIII makes it blink as a PN.  No central star seen.

NGC 6644, PN in Sgr, 10.7v, 2.5”: @205x, small but bright & stellar, blinking with OIII.  Soft edged, bluish disk, no central star.  333x made the disk more apparent but did not give more detail.

IC 4776, PN in Sgr, 10.9v, 8”: @205x, bright and small, bluish, blinking with OIII.  Soft edges and no central star.

NGC 6526, Bright Nebula in Sgr, and part of M8, 40’ size: A real stunner and an easy Telrad find.  @ 121x the M8 complex filled the field; UHC was best filtered view, bringing out much detail.  6526 is the SW portion of M8, and was a bright sweep of nebulosity, providing contrast for the dark nebula dividing it from NGC 6523, the NE portion of M8.  A very bright bow-shaped nebula appeared at the end of three stars near the SW tip of the dark nebula, which I took to be 6526 but which I find out now is the Hourglass Nebula.  Panning around the scene, there was more, fainter nebulosity to the north and east, and many pretty groups of stars.

NGC 6309, PN in Oph, 11.5v, 20”: “Exclamation Point Nebula”: Bizarre looking bright cigar shaped PN elongated 3:1 NNW-SSE with a bright star off the NNW tip, making it appear as an exclamation point.  Used 333x; UHC helped contrast.  The NNW portion of the PN is brighter.  According to Wikipedia it is quadrupolar but I did not resolve the separate portions.

M 2-9, PN in Oph, 13.2v, 60”x30”: “Minkowsky’s Butterfly”.  @ 333x a small, elongated 3 or 4:1 N-S.  It looks rather like a galaxy, overall very faint but with a small brighter round central region with quickly fading and tapering tips.  The center flashes a central star with averted vision and brief moments of good seeing.  Filters don’t seem to help the view.   

NGC 6712, Globular Cluster in Sct, 8.1v, 7.2’:  @ 333x, pretty large and irregularly round, with a couple dozen stars resolved in front of the misty grey core, and more stars sparking out to the west side.  Very dense field of stars mixing up with the cluster’s stars.  (I used M11 as the start of the star hop to this object, and had a nice if not picturesque view of the center of the cluster, its red star reigning over the crowds of faint and fainter stars surrounding.)

IC 1295, PN in Sct, 12.5v, 102”x87”: Unfiltered at 333x a large round haze, mottled through the central region.  OIII and UHC both help.  The edge appears uneven at first but it is really round, with some parts dimmer than others; the south / southeast edge is brightest.  The center is more strongly mottled with the filters.  A second planetary, K 4-8, was plotted on the atlas just to the NW, and I found it blinking with the UHC filter.  A nice contrast in sizes of planetaries in the same field of view.

NGC 6604, OC with nebulosity in Ser, 6.5v, 4’: At 86x and 1° TFOV, the large nebulosity is an irregularly round fairly bright patch around a handful of stars in a shallow arc, with chains of stars stretching to the north and south.  UHC brought out more faint wisps of nebulosity.  Nearby to M16 which was visible in the 80mm finder.

Peimbert Costero PC 19, 12.2v, 14”: PN in Ser:  At 333x, small, fairly faint, bluish, blinks with OIII.  Two close fainter stars make a string with it pointing NW.  I think this was put on the AL PN list to make people research it: Digital images of the PN reveal it looks something like a spiral galaxy with bright “arms” in the SW and NE part of its “halo”.  It is a “Point-Symmetric” PN, meaning the star’s material is being ejected by a bipolar rotating episodic jet, giving it its weird shape. 

NGC 6572, PN in Oph, 8.1v, 16”x13”: “Emerald Nebula”: Very bright and a very beautiful deep green color.  Out of round and orientated N-S.  I think I saw a central star flash out of the very bright central region when using averted vision, very brief.  The edge is hazy and seems to be a diffuse outer shell. 

I made another unsuccessful attempt for Pease 1 in M15.  The globular itself bristled with resolved stars down to the brilliant core, and was very impressive at 333x.  My main struggle to find the planetary is to pick out the “trapezium” stars to begin the star hop on the finder chart.  I eventually just tried blinking with my OIII in the general vicinity of where I thought Pease 1 was, but with no certainty.  Today I went back to blackskies.org and found a good picture of the trapezium stars’ location – turns out I have been searching for them too far away from M15’s core.  I’m hopeful next time out I will be able to find the PN.

NGC 7094, PN in Peg, 13.4v, 99”x91”: Visible in 80mm finder as a stellar point.  @ 333x central star is visible within a round faint moderately large shell; view improves with OIII

NGC 7042, GX in Peg, 12.2v, 2.0’ x 1.8’: I found this easier to hop to from Gamma Equuleus than from M15 where I just was.  @ 205x, fairly faint, pretty large, 3:2 elongated NW-SE, bright core and clearly disrupted diffuse halo [Sb spiral].  Another galaxy in same field, NGC 7043 to the NE as a small, faint round glow with a brighter core. 

NGC 7177, GX in Peg, 11.4v, 3.1’x2.0’: Immediately see a strange sight: the bright core is elongated (barred?) and sits at a sharp angle SW-NW compared to the faint halo, which is E-W 2:1.  Pretty large overall.  The halo has diffuse edges and is mottled. 

NGC 6991, OC in Cyg, 6’x4’ & 12’x8’: At 125x, open cluster who’s brighter loop of stars form an omega or octopus shape, with a bright red star as one of the arms.  A mini little dipper asterism is to the south.  Loose, poor, no concentration or nebulosity.  [It seems I observed John Herschel’s cluster, rather than William’s, which is close to a 5.7 magnitude star to the NE.]

NGC 6997, OC in Cyg, 10.0v, 6’: In the east coast of the North America Nebula; so viewed without filters otherwise it would be obscured.  At 125x, roughly circular arrangement of ~60 stars within a couple magnitudes of each other.  A distinct “S” shape runs through the middle.  Nebulosity apparent even without filters.  A poor, loose, but pretty cluster.   

NGC 6946, GX in Cyg, 9.1v, 11.5’ x 9.8’: “Fireworks Galaxy.”  Its brightness spread over a large area so appears dim; seen through a heavy sprinkle of foreground stars.  Bright small core with three arms easily seen, the most prominent of which sprouts from the core and heads north in a thin line before sweeping and spreading to the east.  Its opposite heads west and is much thicker.  A third is tucked under the north arm in a tighter arc to the core.  I know from prior reading there are several HII regions to be seen in this galaxy but did not bring a finder.  I see one in the NE rim of the northern arm [A4]; a bright oval in the third arm between the north arm and the core [HB481-486]; a nearly detached cloud at the tip of the eastern arm [H1-2]; and a very faint cloud in the gap between the eastern and northern arms [A36-41].  [Identified come HII and star clouds with a finder from Deep Sky Forum.]

NGC 7008, PN in Aquarius, 8.0v, 44” x 23”: Unappealingly called the “Fetus Nebula,” which does, however, describe the appearance fairly well.  Pretty large, it would be oval shape if the SW side of it wasn’t raggedly missing from the rest, with some extensions hanging down from the remaining nebula.  It reminds me a little of one of those broken heart pendants, which is supposed to be matched with a corresponding, missing half.  The NE side is smoothly oval round, and has a bright rim.  Bright star at the SSW rim, the nebula seems to rise up from it like a gene from a bottle.  There are a few stars superimposed on the nebula but there is one in the geometric center.  What a weird sight.

NGC 6824, GX in Cyg, 12.4v, 1.7’x1.2’: Fairly large and oval, 4:3 NE-SW, bright core, stellar nucleus, and diffuse halo.  Star on the southern tip of halo; very bright star just to the north.

NGC 7023, BN in Cyg, 7.1b, 5’: Bright star with extensive milky nebulosity surrounding it.  Seems to have a dark lane to the SW radiating from the star.  Nebulosity permeates the whole view.

NGC 7129, Cluster with nebulosity in Cep, 11.5b, 2.7’: About 7 stars with extensive nebulosity in the area.  7129 forms around three stars in a squat triangle shape.  The nebula seems not just bright but dusty, as if we could see the grains of dust floating in the star beams.