Supernova and comet

[Robin Scagell]

A couple of photos taken on the night of May 23–24 using my Sky-Watcher 80 mm ED on HEQ5 mount with Atik 314l+ camera from Flackwell Heath, Bucks.


Comet Johnson. 4 x 30 sec L, 30 sec each R, G and B (bin 2). Not perfect driving! The comet was easily visible on the locating exposure of about three seconds.


NGC 6946 and supernova. Five x 40 sec exposures in L only, bin 2. The galaxy didn't show up even on my 8-binned trial exposures of several seconds, but I recognised the star field. The SN showed up before the rest of the galaxy. Equipment problems meant that I had to use old dark and flat frames, and some flat-fielding would have been good. Some exposures on the camera were completely blank, for unknown reasons.

Robin

[brian livesey]

Fine images Robin. It's truly amazing what can be achieved these days with digital imaging applied to small apertures.

[mike a feist]

An interesting photograph, Robin, showing the smudgy tail of the comet. What is the orientation of the image and rough magnitude of the stars shown. I was trying to judge the scale to tie it in with the visual observations that I made at the same time. regards mike

[Robin Scagell]

The 'bright' star above the comet is mag 10.56 and the one to its right is 10.00 according to SkyMap. The faintest stars shown are around mag 15. The FOV is 51 arcsec wide and 38 high, with north more or less at the top.

Aligning a CCD camera on the sky is a matter of turning it in the eyepiece mount so that pressing the RA button makes the stars move roughly east–west, so often it isn't precise.

Robin

[mike a feist]

Thank you Robin, so none appear in Uranomethria, which has 9.7 as its faintest. Of course many stars fainter than this can be seen even in my various small instruments and these scopes have much much larger FOVs too. Hence the reason for me not being able to match what you photographed (imaged) and what I saw visually. regards mike.

[mike a feist]

Hello Robin, I think that should be 51 arcmins and not arcsecs.In a later photograph of something else you do say arcmins (not arcsecs). regards maf

[Robin Scagell]

Yes, you're right of course! Sorry for the error.

Robin