M3 Globular Star Cluster (2024, First Light AT92) (Mark Germani)

M3 Globular Star Cluster (2024, First Light AT92)

Revision title: Final (8 hours)

Several weeks ago, thanks to the astonishing generosity of a fellow astrophotographer, I received an Astro-Tech AT92 APO refractor. Half as wide again as my trusty Zenithstar 61, this is an incredible upgrade for me.

I was a little worried about backspacing, but at 57mm from the stock flattener, there was surprisingly little coma on my first night out. I added another 2.5mm and added a second night of imaging, but it didn't seem to make any difference with the coma - in fact it added a funny little bulge to the top-right corner of all of the stars, like a small unresolved double. Not sure what I did wrong, maybe tightened the pressure-fit on the flattener too much? Anyway, I'll play around with it. It's nearly bang-on, and BlurXterminator sure helps.

There are some small artifacts from my quick processing here - with so many nearly-resolved stars, they seemed to blend together and create faint strings which look a little odd after processing. But I wanted to get this image up ASAP. It has been aggressively drizzled, and I ditched about 20% of my subs as I haven't yet installed my auto-focuser and my focus drifted a bit on the first night. I have only cropped the final image a little bit, as I wanted to feature as much of the lovely FOV as possible, including NGC 5263.

Many thanks to the donor of this wonderful telescope!

Original
Final
E

E

Title: Final (8 hours)

Description: Doubled the integration time, and reprocessed with slightly more care to avoid "strings". More stars resolved, and much tighter focus. Tighter crop, too.

Uploaded: ...

The OSC Club (One Shot Camera)
Light Polluted skies
ASI533MC Pro
Optolong L-Pro filter
The refractors!
Canadian Astrophotography
Pacific Northwest Astrophotographers
Musical Imagers
Broadband under Bortle 7/8/9

* All *
Astro-Tech AT92
Globular Clusters
Messier Objects
New General Catalogue Objects

	Distinct awarded users	Total awarded images
Image of the day
Top picks
Top pick nominations

	Image of the day	Top pick	Top pick nominations	Total submitted
Deep sky
Solar system
Extremely wide field
Star trails
Northern lights
Noctilucent clouds
Landscape

	Image of the day	Top pick	Top pick nominations	Total submitted
Backyard
Traveller
Own remote observatory
Amateur hosting facility
Public amaeteur data
Professional, scientific grade data
Mix of multiple sources
Other
Unknown

Submitted The date and time when you submitted this image for IOTD/TP consideration.	...
Views by Submitters (available since September 19th, 2023) Every image is assigned to 50% of available Submitters. In the event that at least 80% of them don't view the image before its time in the IOTD/TP process expires, it's assigned to the other 50% of Submitters and the process begins anew.
Promotions by Submitters When 3 distinct Submitters promote the image, it moves on to the next stage of the process: evaluation for Top Pick status. This requirement, in addition to anonymization of images and distribution to only a subset of them, prevents biases and ensures that the best images are selected.
Promotions by Reviewers When 3 distinct Reviewers promote the image, it moves on to the next stage of the process: evaluation for IOTD status.
Early dismissal Staff members have a lot of images to inspect on a daily basis, and they can dismiss images if they believe they don't meet the requirements for IOTD/TP selection. If an image is dismissed 5 times, it's removed from the process. This streamlines the process and ensures that any bias present in promotions could be overruled by other staff members.

Status	Advanced success
Started	...
Astrometry.net job	9880300
PixInsight job	JI048R77TKPOGCA00R2F0DBYVQYN2UOB
PixInsight queue size	n/a
PixInsight stage	TASK_LOG

RA (center)	13h42m11s.44
RA (top/left)	13h44m05s.44
RA (top/right)	13h44m09s.75
RA (bottom/right)	13h40m16s.52
RA (bottom/left)	13h40m14s.12

Dec (center)	+28°22′47″.1
Dec (top/left)	+27°56′50″.7
Dec (top/right)	+28°47′54″.7
Dec (bottom/right)	+28°48′39″.3
Dec (bottom/left)	+27°57′34″.9

Image Index:

Contribution Index (beta):