EAA Observing Session: 16, December18/12/2025
Astronomy

Session Data

  • Date:  16/12/2025
  • Time:  21:53 – 00:06 UT
  • Seeing: II. Good – Slight
  • Transparency: III. Clear with slight haze
  • Temp: 4 C,
  • Air Pressure: 1018mb
  • Humidity: 92%
  • Dew Point: 3 C
  • Wind Speed: 2 mph
  • Average SQM:  20.30magn/arcsec^2

Scope: Altair 150mm RC f/6  Camera: ZWO ASI 183MM. Darks and Flat subtracted

Further testing of the collimation of the 150mm RC, which is a lot better now. Not imaging quality, but not bad for EAA.

I also took about 20 flats using Sharpcap’s flats wizard. Like the one in NINA, this calculates the best exposure and then takes how many flats you have requested and then combines them into a single Master Flat.

M52, NGC7654

Located 6.0 degrees, PA 298 degrees of Beta Cas in Cassiopeia

Quite a concentrated cluster spanning about 8 arc min at its most concentrated with an overspill of stars outside of that to the Northeast.The majority of the stars are in the 11.0 – 12.0 mag range. There is also a bias in direction of these with a PA 136 degrees

Total Integration Time:  270 sec

M74, NGC628

Located 7.0 degrees, PA 343 degrees of Omicron Psc in Pisces

A textbook face on spiral. Categorised as an Sc type, we have three bright spirals. The one to the Northwest is jagged and not smooth as though the arms are being perturbed in some way. The end of this looks to have a hook that backs back in on itself. All these spirals show small bright knots which indicate areas of star formation.

Total Integration Time:  480 sec

M109, NGC3992

Located 0.6 degrees, PA 119 degrees of Gamma UMa in Ursa Major

With quite a sparse star field you can see that we are looking out of the plane of the Milky Way.

An angled on view of a Sbc type spiral with three visible arms. You can clearly see the bar extending out at each side of the bright core. The bar doesn’t look to be straight, but that maybe just because the integration time is so short.

We also have two obvious galaxies in the frame. Both appear to be nearly edge on.

PGC37700 15.4 mag to the Northeast, with a position angle of 150 degrees. You can make out a little of the core but no bright pinpoint centre.

PGC37553 13.4 mag to the Southwest, with a 175 degree PA. Here you can make out the brighter core easily.

Total Integration Time:  585 sec