M15 by Eamonn Ansbro

My guess Dave L is that Eamonn is using a NABG CCD camera which resulted in blooming on the star, especially as it's by far the brightst star in the image.

My guess Dave L is that Eamonn is using a NABG CCD camera which resulted in blooming on the star, especially as it's by far the brightst star in the image.

Wrong star Michael, I'm talking abouit the one to the lower left, 8-9 oclock position.

Hi all,

This was the very first automated LRGB raw image I took using ACP Observatory Control Software). This involved scripting in the globular cluster M 15, setting the Luminance filter to 30 secs exposure, the Red, Green and Blue filters at 10 seconds each. There was no post processing. It was taken 14 Oct at 00.30 hrs. I was taking other black & white images of selected galaxies at the time that were given to me by Dave McD for the new IFAS AOP SN search pilot programme at the time.

I am using 0.4m SCT OTA and a Paramount GT1100S (the version before the ME). The camera is an Apogee AP7p (QE 85%). (512x512 at 24 microns per pixel), using control software MaximDL. The OTA works at f/5 using a X0.5 Optec reducer. This gives a wide field of view of 25' X 25', and a 2.92 arc second per pixel resolution. I use an Optec TCF with FocusMax that kicks in every half an hour for one minute to correct for focus shift as the night time temperature drops.

Eamonn A

Apologies Dave! Must read posts slower!

Yes it does look unusual alright. In Eamonn's image, it looks like a double. In your image however, there's no sign of such.

The camera is an Apogee AP7p (QE 85%). (512x512 at 24 microns per pixel)Eamonn A

Eamonn - is that the SITe 502 CCD chip?

Dave Mc,

The Apogee AP7p is a SiTe 502A chip. This is a thinned backside illuminated chip. The sensor chip is 12.3 mm X 12.3 mm. The pixel size is 24 microns square. There is poor temperature control. It can go down to -50deg C. The sensitivity is doubled as compared to the old SBIG ST8 camera.

I usually use it at -30 deg C because I have no patience waiting up for another 3/4 hour for cool down time. However on a critical note I do find thermal noise and hot pixels appearing at times.

Eamonn A