UT Jun 13, 2021: Looking for ZTF21abfmbix
Michael Richmond
Jun 13, 2021
On the night of Jun 12/13, 2021,
under good conditions,
I
acquired images of the field of the transient source
ZTF21abfmbix,
as a practice exercise
for the
Kilonova Catcher collaboration.
My images did show (faintly) the transient,
which is a young supernova.
ZTF21abfmbix
The target is one of the (many) candidates discovered
by the Zwicky Transient Facility.
Information on the object can be found at
These observations involved:
- Meade 12-inch telescope
- no focal reducer, so working at f/10
- ATIK 11000 CCD camera
- clear filter, 30-second exposures
- focus in clear at 1.012 yielding FWHM 2.5 pixel
- images binned 2x2
- both guided and un-guided images
Notes from the night:
- small crescent Moon low in West, has no effect on target
- sky clear
- temperature 72 F / 22 C at start (9:22 PM),
dropped to 64 F / 18 C at end (11:31 AM)
- disassembled filterwheel and removed it from camera,
then put it back on the camera, fixed in "clear" position
- used 7-second images with guider, aggr = 0.2 in X-direction.
Seemed reasonable, but turned it off between images 67 and 91
as a test. No big improvement without guiding.
- need to create a new cardboard screen for flatfields
Looks like we'll probably purchase a new filterwheel,
rather than try to repair the old one.
As for images of ZTF 21abdwdwo,
a brief summary is:
- median of all images, 122 x 30-seconds,
does show the target just to the East of the host galaxy.
However, PSF is rather elongated east-west.
- "pruning" the images to remove those with large FWHM (> 5.0 pix),
small roundness (< -0.5),
and photometric zeropoint (> 12.80)
reduces the number of images to 62.
Stacking these "good" images yields a median
image which has a better PSF, and still shows
the target clearly.
Here's a portion of the stacked image.
North is up, East to the left,
and the target is the faint point source just to the
East (left) of the galaxy below center.
Last modified 6/13/2021 by MWR.