Monday, June 4, 2018

alone on the peak

Saturday night I went up to Fremont Peak for a night's observing.  The 80-something percent waning moon rising at midnight kept everyone else from coming out, deep-sky obsessed as most observers are.  Seeing was predicted to be excellent, so I set my mind to observe very close doubles, the planets, and even the moon using the 30-inch Challenger telescope.

It gets dark very late now.  I arrived at 7:30 and opened up, setting a fan behind the mirror to help it cool off.  Then I had dinner and relaxed.  I didn't bother with the setting circles -- I'd need to star hop anyway.  I aligned finders on Jupiter and had a look for a while.  No great red spot, and no moon events -- three were staggered on one side and a fourth, Callisto probably, was way off to the other side.  There was a nice dark barge in the SEB, which seems to have been there every time I've looked the last couple of weeks.  Some white gaps toward the faint southern cap.  The purple festoons riding on the SEB were subdued: they looked more like rolling fog than whipping flags.  There was a thin dark band between the NEB and the northern cap; the band is usually swirled about by the GRS.  Three white separations in the northern cap region.  Most of this was viewed using my binoviewers with the 32mm plossls.

Then I moved on to my program.  Seeing was a disappointing 6-7/10, only getting better after 1am.  Transparency was 4/5, some haziness in the air, also a disappointment -- though the 2700 foot Peak put me above most of the muck in the valleys.  SQML was 21.04 at it's best around 11pm.

Ho 50: It took me a damned long time to star hop (stupid English cross-axis mount and non-RACI finders), and once I got there I found I set the secondary in the wrong position so had to start all over again.  The pair split immediately at 457x.  A little diffraction but no doubt a small blue point just outside the first ring.  Using the 8-inch aperture mask (effectively 8-inch f/18!) had a nice star image of A but B disappeared -- it became an averted vision, threshold object.  Barlow here was no help to show it better.  An 8-inch magnitude limit is 13.4 on a perfect night; so given my conditions I'd say for sure B is in the ~11th magnitude range.  I sketched the star field and used my best estimates of it's magnitude with other stars in view.  Using Aladin now I find SDSS J111314.92+410057.3 is 15.3g, which I say is brighter than H0 50B, and SDSS J111328.37+410828.1 at 16.6g , which I describe as "about as bright."  There are differences in how one perceives magnitude when it is closer to a brighter star, and my stellar magnitude estimation skills are not developed, but I think Ho 50B is fainter than the current data, and if the older data say it should be fainter, then it may well be variable. However, later in the night, I estimated Ho 50B to be as bright as STF 1964D, which is 9.02.  In any case, fainter than stated....
11H 13M 40.09S +41° 05' 19.8" P.A. 35 SEP 3 MAG 6.47,8.36 SP K2III DIST. 114.03 PC (371.97 L.Y.)

UC 2059: I observed this star a few days ago using my 12.5-inch from home, since it's plotted in CDSA and I was casually taking in that section of sky.  At that time I wrote: "Pretty well separated, 1.5 delta mag, not remarkable as I hoped given the odd designation."  Checking Stelle Doppie later I had only seen the AB pair.  There is also HSD1574 Aa,Ab is 0.2" and 11.06; Cou 1422 Ba,Bb is 0.6" and nearly matched 11.20, 11.50.  When I looked Saturday with the 30-inch, I wrote: "Bright star and pair of 11th magnitude stars very close -- but best I could get was an elongation with the seeing; tried 1219x without success."  I did not remember the A star was a 0.2" though at 11th mag I don't think I had a chance at Ab.

3, Beta CrB = JEF 1: Tried out the hexagon mask I made.  At low power the mask sends the diffraction spikes into six directions.  Tried 915x; the diffraction pattern turns into a kind of grid, 6x6 bright squares distorted into an overall wing shape.  I can focus a brighter roundish point but I cannot tell if this is an out-of-roundness due to the binary or just a weird misshape due to the seeing, which is causing the whole image to dance around.  Later in the night, when seeing was somewhat better, I tried again at 457x, and again suspected an out of roundness but nothing I could certainly claim.
15H 27M 49.85S +29° 06' 19.8" P.A. 149.5 SEP 0.31 MAG 3.68,5.20 SP A5+F2 DIST. 34.28 PC (111.82 L.Y.)

Cou 610 = The CrB: Fractured and dancing seeing.  915x, at full aperture and with 8-inch aperture mask, I see a slight out of roundness.  This one should have been a clean split if the seeing was better.
15H 32M 55.78S +31° 21' 32.9" P.A. 199 SEP 0.8 MAG 4.27,6.29 SP B6VNNE DIST. 115.07 PC (375.36 L.Y.)

STF 1964: 457x: Seeing and barlow too messy.  Bright pair wide separated resolves to the double-double.  Ho 50 is about as bright as the Struve B star, which is 9.02

MS Serpens: When marking close doubles in my cut-out copy of Uranometria, I marked "MS Serpens" as T CrB, the famous nova, since Uranometria did not plot T CrB and "MS" seemed to be in the right spot.  The nova is double, supposedly, 0.3" separation.  I thought I might have found it since my notes read: "!  Presents as a wide 1 delta magnitude pair at 457x.  The brighter star just shows an extremely faint point very close split, which widens with the barlow at 915x.  Seeing dependant and almost averted only, though can hold direct vision.  The slightly orange A star loses color with magnification."  However, as I review Aladin now, I cannot find a double star in this section, and the data for T CrB is uncertain.  Besides that the star hop to this area was arduous, and I was not certain of it.  So this one is a mystery.  WDS J15595+2555AB?  JEF 2?  I don't know...  I even made the mistake of writing this as "M 5 CrB" in my logbook... [Later edit: MS Ser and T CrB are not the same stars; seems T CrB at minimum 10th magnitude did not meet the plotting cut off for Uranometria.  I have AAVSO finder charts printed for both, and will give them a go next time I have a chance.]

How frustrating!  After nearly four hours of observing I have only six observations to show for it.  I've said before, I really want to love this telescope, but the physical effort to move it, and the trouble I have using the finders, makes it very frustrating.  I never zipped up my jacket, I was sweating making the effort.  Some of these observations I will try again in my 20-inch for comparison....

I looked at Saturn for a while, trying to use my binoviewers -- but maybe because it was so late, or the scope's damnable eyepiece position was so awkward, I had trouble merging my vision.  I also discovered I still had the 8-inch aperture mask on (did that hinder my MS Serpens view too? I was too tired to remember).  I looked at Mars for a while, which was a few degrees below the moon (which rose through a mist an hour earlier, turning it bloody).  Polar ice, and a wide dark jagged band, but not a good view.  The moon looked ok, but was extremely bright, such that when I tried to move about the observatory I could barely see because my eyes had lost all sensitivity.

I had a look at Antares through the 6-inch refractor finderscope, thinking if anything could split it this would -- yet it did not.  I tried different magnifications, but no split.  It should not be so hard!  The airy disk changed from blood red to a neon green, to taunt me.  Finally, it must be time to stop, so I did.

No comments:

Post a Comment