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Feb 11, 2015    |    Image   0 comments

Arp 210/NGC 1569

Arp 210

Data acquired from January 3, 2015 to January 7, 2015; processed entirely in PixInsight.
Click on image for full scale resolution.

Luminance: 24 x 600″

Red: 6 x 600″

Green: 6 x 600″

Blue: 6 x 600″

Arp 210 (aka NGC 1569) is a super cool little galaxy, and was a fairly difficult target due to its small angular size. Several large star clusters within the galaxy are just visible: Arp 210 is known for its high starburst rate – almost 100 times more than in the Milky Way. This, combined with large numbers of supernovas, make this a very active galaxy. This galaxy is also unusual in that it is blue-shifted (and headed towards us at about 104 km/s).

Processing this image had some additional challenges. I don’t currently have a flat library to use for calibration, so I have been limited to whatever dusk/dawn flats I can get each night. I also can’t always leave the CCD attached to the scope all the time, depending on the weather, so those days where I have to remove it require their own flats. Ultimately, each filter ended up with about 8 flats each, which isn’t really enough. Also, the flats obtained were not of the best quality, since the calibrated frames had nasty gradients that couldn’t be attributed to clouds or moon glare.

The background gradient made the image difficult to process. It was so bad that I was unable to use the DBE (dynamic background extraction) tool in PixInsight to fix the background. I used the ABE (automatic background extractor) and noise reduction tools heavily to try to even out the background. Each step required a mask to cover the galaxy and stars since I didn’t want to lose any data and the galaxy was pretty small to begin with. I did have quite a bit of luck with using HDR Multiscale Transform to bring out detail in the galaxy. Up until the point I used that tool, I didn’t even know that I had captured enough data to show those clusters.

I’m not sure if this image will benefit from another go at processing until I figure out a solution to the flats issue. So much of the time spent processing was to fix defects, and I think in the process I probably lost a bit of data, especially with the diffraction spikes. I’ve added them manually in Photoshop before, but it just feels too artificial and I prefer the “naturally occurring” look.

It’s really fun to image the objects that don’t usually get very much attention. There are some beautiful Hubble images out there of galaxies like this, but it’s still something special to really see it for yourself and get another perspective of it. This galaxy didn’t have any other images on AstroBin, which is a shame since it’s a pretty cool one.

"Starburst in a Dwarf Irregular Galaxy" by NASA / A. Aloisi (STScI/ESA) et al. - http://antwrp.gsfc.nasa.gov/apod/ap081229.html. Licensed under Public Domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Starburst_in_a_Dwarf_Irregular_Galaxy.jpg#mediaviewer/File:Starburst_in_a_Dwarf_Irregular_Galaxy.jpg

Hubble image of Arp 210/NGC 1569 — “Starburst in a Dwarf Irregular Galaxy” by NASA / A. Aloisi (STScI/ESA) et al.

Feb 11, 2015    |    Image    2 comments

Typical workflow

It still feels like I’m in a constant state of fixing things up or calibrating something or another, so I don’t know how “typical” my workflow is at this point. I’m starting to think that crazy is the new typical when it comes to getting all the imaging components to play nicely and not freak out over some random error. At the moment CCD Autopilot is running a filter focus offset measurement, which is taking significantly longer than I thought it would.

It’s 4 am, but I really don’t want to waste any dark time, and I don’t want to put it off until tomorrow night. This would have been done already (and was at one point), but then my older version of FocusMax started crashing on focus changes, and taking CCD Autopilot down along with it, effectively ruining several nights of imaging until I got the hint that FocusMax was throwing temper tantrums.

It ultimately ended up being a weird compatibility issue that was conveniently fixed by testing out the trial of FocusMax 4 and upgrading to that version… By that point I just wanted to image and the filter focus offsets were pushed way down on my priority list since it didn’t take that long to focus anyway.

Tonight, however, ended up as a configuration/calibration fun fest with activities such as running a ~200 point pointing model several times in SkyX to perfect the polar alignment, fresh V-curves in FocusMax, filter focus offsets, and possibly G2V calibration if the sun doesn’t come up first.

Typical workflow for semi-remote operation:

Step 1 (optional): Troubleshoot random problems that have been creeping in over the last week or so.

Step 2: Attempt to come up with an observing plan that balances the fun scientific targets, and the pretty deep sky objects.

Step 3: Add a significant number of targets to your imaging to-do list since that gorgeous nebula always transits at the same time as the asteroid you’ve been following and tough choices have to be made.

Step 4: Tell CCD Autopilot to start doing its thing around sunset – but check back at dusk flat time anyway just to make sure that everything is working.

Step 5: Wait.

Step 6: Open a few images taken before you go to bed to see what goodies you get to process the next day. 50% chance of an image having problems. 99% chance that problem is a user error. Fix if possible/needed.

Step 7: Peek out the window first thing in the morning to make sure that the scope parked like it was supposed to, and hope that you don’t have flood of “guide star lost” emails indicating that the target you really wanted probably clouded over and the targets you added to fill out the schedule probably did just fine.

Step 8: Wait until you have all the images you plan to collect for a particular target and start calibrating and processing. Make mental notes of all the ways your file organizing system can be better.

Step 9: Glare at your processing software of choice until you figure out how to “bring out the best” in your data.

Step 10: Process the data again with all the fun new tips (aka how not to process images) that you learned in Step 9.

Step 11: Success! Now if only AstroBin had a field to measure blood, sweat, and tears…