NGC 2903 - First Galaxy of the Season (Again 2019)

NGC 2903 is once again the first galaxy I have imaged for galaxy season.  It is a barred spiral galaxy about 20 million light-years distant and popular among amateur astronomers as it is easy to find. Being in the constellation Leo, near the top of the lion's head it was in the perfect spot for me to image.  This year I have a new larger telescope so I may go after more galaxies this year.  I am happy with how this one turned out and processing was very easy compared to my last couple of projects.

The spiral arms show more detail than last years image and along with the details of the bright core and extraordinary dust and gas clouds makes for a pleasant image. NGC 2903 exhibits an exceptional rate of star formation activity near its center. The size of this galaxy is just a little smaller than our own Milky Way at about 80,000 light-years across making it a good twin of us (source: APOD).  If you have a good eye just below the galaxy there is a small 'little fuzzy', this is PGC 27115 - UGC 5086, Stellarium has it listed as an active magnitude 18.00 galaxy. 

NGC 2903

Location: Home Monroe, CT
Date: 3-5-19, 3-7-19, 3-25-19
Camera: ZWO ASI1600MM-Pro
Telescope: Astro-Tech AT115EDT 115mm Refractor Telescope
Barlow: None
Focal Length: 805mm
f/7
Focal Reducer: Astro-Tech 0.8x Focal Reducer/Field Flattener for Refractor Telescopes
Mount: Orion Sirius
Filter Wheel: ZWO EFW 8x 1.25"
Filter: ZWO R, G, B, L
Autoguiding: QHY-5L-II-M attached to an Agena 50mm Guide Scope with Helical Focuser
Exposure: R 40 x 90, G 39 x 90, B 38 x 90, L 57 x 90 (4.4 hrs)
Gain: 139
Offset 21
Temp: 0 C
Post Processing: PixInsight and Photoshop
https://kurtzeppetello.smugmug.com/
http://astroquest1.blogspot.com/

Test Run of My Travel Set Up - Imaging Nebula with a Full Moon

The first question is why image nebula when the moon is up?  The answer - No choice or don't try.  For my wife's 50th birthday we are going on a trip to Costa Rica and so I decided I needed a new telephoto lens so I purchased a nearly new Canon EF 200mm f/2.8L II USM Lens from B&H which can be used for normal imaging as well as astrophotography.  I did not want to bring a huge mount on the airplane so I i purchased a nearly new iOptron SkyGuider Pro Camera Mount from High Point which can be attached to any sturdy camera tripod. Great, I thought all is set. Southern Hemisphere objects such as the Running Chicken Nebula, eta Carinae Nebula, and the Southern Cross are low but visible. Unfortunately, the timing of our trip happens to be when the moon is out, hence, this test run. 

So on March 17, 2019 the moon was at 87%, equivalent to when when will be Costa Rica, I did a test run on Orion - Horsehead Complex and the Rosette Nebula which were both closer to the moon than the above mentioned. In order to lessen the moon glow I use the Astronomik UHC Clip-in filter which has helped me in the past with some nebulae.

The set up of the SkyGuider Pro was real easy.  The hard part was centering the objects - not so much with Orion as it is a very easy to locate. That said I did not center it well because it was going behind some trees and I wanted to get it before it was gone.  The Rosette took a little longer to find as it was dimmer and the nearby stars were masked by the moon glow.  This may be the biggest problem I face.  I did not try to center this either when I finally located it as I was getting tired and the point of this test was to see if I see the nebula. 

The test was made using the following camera settings: 30-seconds, f/3.5, ISO 1600 for the nebula images and 8-seconds for the Sirius image.

Raw Images:

Minor Processing:

Well, in my opinion the results are promising. The stars are round when viewed at full frame but are  not perfect if the image is zoomed in.  The nebula resolved out well for just a thirty second exposure. Judging by the background light, I am not sure about doing 1-minute exposures with the moon so 30-seconds may be my limit anyway. I did some very minor processing on the images to get an idea of how hard it will be. Not surprisingly the noise was the biggest problem since it was only one frame,  more exposures will help obtain a better image.

Individual Exposures:

Test Run
Location: Home Monroe, CT
Date: 3-17-19
Camera: Canon T3i/600D modified
Lens: Canon EF 200mm f/2.8L II USM
Focal Length: 200mm
f/3.5

Mount: iOptron SkyGuider Pro on a Manfrotto Tripod
Filter: Astronomik UHF Clip-in
Autoguiding: none
Exposure: 1 x 30s
ISO: 1600
Post Processing: PixInsight and Photoshop
https://kurtzeppetello.smugmug.com/
http://astroquest1.blogspot.com/

Rosette Nebula using the Hubble Palette (SHO)

This image shows the Rosette Nebula (Caldwell 49 or NGC 2237) captured using narrowband filters which give it the psychedelic look.  The nebula is located 5200 ly away in Monoceros and is 130 ly across.  The central star cluster (NGC 2244) was discovered in 1690 long before the nebula.  This object is an emission nebula created by young stars exciting atoms in a could of gas and dust which it turn causes them to emit radiation themselves producing the colors we see.

There are several interesting parts on this nebula such as the dark dust lanes on the upper left and the gold streamers on the bottom right.  One thing in particular is the blue loop in the central portion which seems to be part of the star cluster.  This loop is what caused me to go back and totally reprocess this for a second time as I somehow degraded it on my first attempt.

This half of this data was obtained during a near full moon and the other half during a partial moon.  Because I was using narrowband filters the moon is less of a factor as narrowband filters only allow light of certain frequencies pass.

The filters:

Hydrogen-Alpha – 656.3nm
This light is created by ionized hydrogen dropping one energy level.  H-alpha is in the red part of the spectrum and contributes to the overwhelming red color of most nebulae as seen in normal RGB images.

Oxygen-III – 500.7nm
This line is given off by doubly-ionized oxygen atoms, meaning the electrons are dropping two energy levels. This line is in the blue-green portion of the spectrum.
Sulfur-II – 672.4nm
Singly ionized sulfur emits light in the deep red part of the spectrum, beyond H-alpha. It is a weaker emission than H-alpha and OIII, but it is the most common filter used after these two.
(source: Starizona)

This is my second strictly narrowband image ever, the first being the Wizard, and I am much happier how this one turned out although I there are many better ones out there than my image.  I normally collect images using a gain of 139 because Gary Imm and Chuck Ayoub (thanks Gary and Chuck) use that as a standard, however, Gary used 300 on his recent NB image the Fish Head (https://www.astrobin.com/389550/?nc=collection&nce=910) so I figured I would try it.

I tried many combinations using PixelMath and straight combos before settling on this SHO version. I used both PI and PS extensively doing new things in both in order to bring out gold rim and cyan interior.  What a pain in the neck to process, I though narrowband processing was going to be easy but it anything but!

Lastly, if interested, I did a video on YouTube that compares imaging with narrowband filters during a full moon vs. partial moon.  I had to collect over several nights anyway so decided to make the best of it with an experiment.

Video Link: https://youtu.be/9AvPAGezNpk
Web Post: http://astroquest1.blogspot.com/2019/03/how-moonshine-affects-narrowband-imaging.html

Updated

Original

Rosette Nebula (NGC 2237) and NGC 2244

Location: Home Monroe, CT
Date: 3-11-19, 3-12-19, 3-17-19, 3-18-19, 3-19-19 

Camera: ZWO ASI1600MM-Pro
Telescope: Astro-Tech AT115EDT 115mm Refractor Telescope
Barlow: None
Focal Length: 805mm
f/7
Focal Reducer: Astro-Tech 0.8x Focal Reducer/Field Flattener for Refractor Telescopes
Mount: Orion Sirius
Filter Wheel: ZWO EFW 8x 1.25"
Filter: ZWO Ha, OIII, SII
Autoguiding: QHY-5L-II-M attached to an Agena 50mm Guide Scope with Helical Focuser
Exposure: Ha 51 x 180, OIII 46 x 180, SII 51 x 180 (7.4 hrs)
Gain: 300
Offset 21
Temp: 0 C
Post Processing: PixInsight and Photoshop
https://kurtzeppetello.smugmug.com/
http://astroquest1.blogspot.com/

Moonshine Affects on Narrowband Imaging (Rosette Nebula)

Between the weather, small field of view, and normal obligations it is a wonder I ever get any images so I had a small window to get the Rosette Nebula before it goes away for the season.  The moon was returning so RGB would have been pointless so I decided this would be a good candidate for my second narrowband (NB) image ever.

My setup is as follows:

Camera: ZWO ASI1600MM-Pro
Telescope: Astro-Tech AT115EDT 115mm Refractor Telescope
Focal Reducer: Astro-Tech 0.8x Focal Reducer/Field Flattener for Refractor Telescopes
Mount: Orion Sirius
Filter Wheel: ZWO EFW 8x 1.25"
Autoguiding: QHY-5L-II-M attached to an Agena 50mm Guide Scope with Helical Focuser

Other:
I have been using a gain setting of 139 since I started using the ASI1600 mainly because Gary Imm and Chuck Ayoub use 139, recently however, Gary recommended using 300 for NB imaging so I figured I would give it a try.

The comparison:
The following table lists the conditions each of the frames were were collected and they correspond to the images that follow.  The single frames were opened in PI and only the STF function was run on them so they could be compared in there most basic state. They were saved as tiff files and imported into PS so they comparison table could be made.  The stacking was done in PI and again, only the STF function was run on the images.

For more checkout the video:
https://youtu.be/9AvPAGezNpk

	Ha	OIII	SII
Single 1	87% moon ~ 40° angular dist.	35% moon ~ 35° angular dist.	35% moon ~ 35° angular dist.
Single 2	99% moon ~ 60° angular dist.	99% moon ~ 60° angular dist.	99% moon ~ 60° angular dist.
Stacked with 1 only	87% moon ~ 40° angular dist.	35% moon ~ 35° angular dist.	35% moon ~ 35° angular dist.
Stacked with 1 and 2	Both	Both	Both

Single Frame

Stacked

Conclusions:
I thought I was not going to be able to use the additional data collected when the moon was much brighter as the frames examined in PI - Blink looked much worse than the lower moon frames.  However, after looking at all the frames and data together, I am glad I kept everything because it looks like the additional frames added some beneficial detail.

The individual Ha data looks almost the same from both nights which makes sense since their intial conditions were close.  The OIII was affected most by the moon shine but still the stacked image using both sets of data looks a bit better.  The SII also shows a bit of degradation with the moon shine but not as much as the OIII.  Again, the stacked image is still better.

Anyways, I am glad I did this little experiment so I have a better understanding.  Although collecting when the moon is out it is not great data, it is better than not collecting data.

Data:

IC 2169 and Other Blue Reflections!

There are several reflection nebulae as well as dark nebulae in this image from a portion of constellation Monceros.  The largest being IC 2169 located in the bottom left.  The nebula is blue due scattered light from a nearby star coming in contact with dense grains of interstellar dust, scattered tends to be blue rather than red as in emission nebulae.  There is a interesting dark dust lane which begins in the nebula seems to stretch to IC 2167 which is on the middle right.  Stellarium has this listed as interstellar matter which it is composed of.  On the top are NGC 2245, closer to the center, and NGC 2247 closer to the top edge.  Both of these are blue reflection nebula with a bright core than IC 2169 and both seem to have dark dust clouds near by.  This whole area has many colorful blue and orange stars of all sizes.

I really like imaging these types reflection nebula but I find processing them to be quite difficult.  I had to do a lot of processing in order to make it look presentable and unfortunately every object has its own processing method.  I have a loose flow-process that I do but it varies quite a lot from one object to another object.  Of course I wanted to get more data but my limited viewing window along with poor weather conditions in southern Connecticut prevent that.  I would have had another 45 minutes but I must have had dirt on my glasses when I was focusing - oh well.  My ASI1600 is back in working order and I am imaging with it again.

IC 2169, IC 2167, NGC 2245, and NGC 2247
Location: Home Monroe, CT
Date: 3-4-19, 3-6-19, 3-9-19

Camera: ZWO ASI1600MM-Pro
Telescope: Astro-Tech AT115EDT 115mm Refractor Telescope
Barlow: None
Focal Length: 805mm
f/7
Focal Reducer: Astro-Tech 0.8x Focal Reducer/Field Flattener for Refractor Telescopes
Mount: Orion Sirius
Filter Wheel: ZWO EFW 8x 1.25"
Filter: ZWO R, G, B, L
Autoguiding: QHY-5L-II-M attached to an Agena 50mm Guide Scope with Helical Focuser
Exposure: R 47 x 90, G 52 x 90, B 50 x 90, L 64 x 90
Gain: 139
Offset 21
Temp: 0 C
Post Processing: PixInsight and Photoshop
https://kurtzeppetello.smugmug.com/
http://astroquest1.blogspot.com/