UT Apr 09, 2018: Observational Astronomy class measures SZ Lyn

Michael Richmond
Apr 15, 2018

On the night of Apr 08/09, 2018, Jen Connelly and students in the Observational Astronomy (PHYS 373) class observed the variable star SZ Lyn.

The main setup was:

Notes from the night:

The object is located at

  RA = 08:09:35.75   Dec = +44:28:17.61

A chart of the field is shown below. The size of the chart is about 24 arcminutes on a side.

I've marked the location of several comparison stars, which also appear in light curves below.

  star        UCAC4              B          V
   A       673-053176        11.706     10.852
   B       673-053163        
   C       672-051317        12.694     12.031
   D       672-051319        12.279     11.631
   E       673-053186        13.233     11.887



The sky brightness increased slightly throughout the run.

The number of objects found was relatively constant.

The FWHM decreased considerably once the electric focuser could be used.

Image adjustment factor shows a bump late, followed by a very sharp rise. Looks like some clouds came near the end of the run.

Using aperture photometry with a radius of 10 pixels (so a radius of 13.2 arcsec), I measured the instrumental magnitudes of a number of reference stars and the target. Following the procedures outlined by Kent Honeycutt's article on inhomogeneous ensemble photometry, I used all stars available in each image to define a reference frame, and measured each star against this frame.

Sigma-vs-mag plots show that the floor was about 0.012 mag. The brightest object -- with a large scatter -- is SZ Lyn itself.

Here are light curves of the variable and the field stars.

Last modified 4/09/2018 by MWR.