Experimenting at the Club's Observatory

 First off, it's been a while ... 

The last clear night that I was able to image was on October 3rd. So, apologies for taking so long between posts. The weather has been horrendous and travel for work forced me to miss the one clear night we had in November. I was super excited to see a clear forecast for Thursday night (December 14th). Our astronomy club has an imaging group, we're called the Tuesday Night Imagers. the leader of our group posted on the forum of our website that Tuesday would be Thursday this week. One advantage of winter is I can make it out to the observatory after work and get a few hours of imaging in and still get home at a reasonable time. 

We made our plans ahead of time. The plan was to try my personal camera, the ZWO ASI2600MC-Pro on the club's Celestron 14" Edge D Telescope. Our club has the 14" and a Tele Vue NP-101is mounted on an Astro Physics AP-1200 mount. We have an Atik 383L+ Color camera for the 14". A great camera, but it is an older CCD camera and is starting to show it's age. We are actively discussing what camera to get to replace it. We wish to stick with a One-Shot Color (OSC) camera for simplicity and convivence. Technically, my camera is a great match for the NP-101is but not for the 14". Even with the 0.7x focal reducer, the 14" has focal length of 2,738 mm. Therefore, my camera's small pixels result in a very over-sampled image scale with the 14". This is typically not desirable. However, we have seen some great results from similar setups and decided to give this a try. 

I got to the observatory around 5:30 pm. The observatory director, the leader of our imaging group, was unable to make it out to the observatory due to a last minute issue. Typically, the observatory director and another member of our group are the main operators of the telescope. The other telescope operator and I got the telescopes going. My camera on the 14" and the other telescope operator put his ZWO ASI1600MC-Pro on the NP-101. The observatory director and a couple of other members of our imaging group joined us via Zoom. 

The skies were not great. lots of high/thin clouds or haze especially towards the western horizon. Of course, that's exactly where we wanted to image. We wanted to get data on Comet 12/P Pons-Brooks which is near the bright star Vega. We tried for about an hour, but the data was not looking good. Autofocus was struggling and there was little signal from the comet. I have not tried to process the data from the 14" yet but the other telescope operator managed to get a nice image (especially considering the conditions). 

As it was also the peak of the Geminids meteor shower, we did try to get outside and see if we could see meteors. We saw about four or five. We also noticed skies were better towards the Southeast, where the constellation Orion was rising. We decided to give up on the comet and slew to the Horsehead Nebula (Barnard 33). We slewed to B33 and got both telescopes framed as best as we could. We were feeling the pressure to get imaging quickly, so we didn't rotate the camera or refine (manually) the relative pointing of the telescopes to one another, a disadvantage of two scopes on one mount. We dialed in our exposure settings, 120 sec subs at Gain 100 with an Offset of 50 for me and started collecting exposures. The results looked really good. The stars were nice and round. We imaged for little over an hour. It was a work night, skies weren't the best, and both of us had a pretty good drive home. This is the resulting image from the night's work. Pretty encouraging results!

The Horsehead Nebula (B33) from the BAA's Beaver Meadow Observatory on 12/14/2023.

Processing

There was a lot of conversation in our club's forum leading up to Thursday night and again afterwards regarding how to capture and process images with this scope/camera combination. We are lucky to have some talented imagers in the group, one in particular who is both very talented and technically knowledgeable. This person was a key participant in those discussions and I'm personally very grateful for his mentoring.

All pre and post processing was performed in PixInsight. Pre-processing: All 34 images were examined in Blink, 2 were rejected. The remaining 32 images were calibrated, registered, and stacked in WBPP with 1X Drizzle integration, astrometric solution, and auto-crop enabled. 

Linear Post-processing: Gradient was removed with the GraXpert script (AI mode), initial deconvolution with BlurXT in Correct Only mode, color calibration SPCC, second deconvolution with BlurXT, noise reduction NoiseXT, and the image was made non-linear with HT. Non-linear Post processing: Stars were removed with StarXT. Stars: Saturation curve applied with CT and green noise removed with SCNR. Starless: Multiple iterations of CT were applied to increase brightness and contrast, Saturation was added with CT, green noise was removed with SCNR, and noise reduction was further reduced with NoiseXT. The image was sharpened with LHE at 3 different kernel sizes and MMT. Dark structure was enhanced with the DSE script and stars were screened back in with Pixel Math. No down sampling was performed. 

What is it?

The Horsehead Nebula (Barnard 33) is a small dark nebula silhouetted against the emission nebula IC434. B33 resembles the profile of the head of a horse. It is a concentration of dust and non-luminous gas that blocks light of the nebula behind it. 

Annotated image of the Horsehead Nebula

How big is it?

This object has an angular distance of 6.0 x 4.0 arcminutes on the night sky. The object is 2.8 light-years (ly) across. 

How far is it?

It is located about 1,600 light-years (ly) from Earth in the Constellation of Orion.

How to find it?

It is located close to Alnitak, one of the 3 belt stars in Orion. This makes it easy to find. However, it is much easier to photograph than visually observe. To give you the best chance of success in visually observing it, use a large aperture telescope, use an H-beta nebula filter, and get to dark skies. It is tiny and it is essentially like trying to find a black fingerprint on a black tablecloth. Try to find the emission nebula IC 434 and look for the absence of the nebula. Photographically, this target shows up relatively easily and can be captured with and without the use of filters. 

Finder Chart for B33

Image Details:

Capture Date: 12/14/2023

Location: North Java, NY (BAA's Beaver Meadow Observatory

Telescope: Celestron 14" Edge HD w/0.7x Focal Reducer

Camera: ZWO ASI2600MC Pro

Filter: N/A

Mount: Astro Physics AP-1200

Exposure: 32 exposures at 120 sec / Gain 100 / Offset 50 / -10°C each for a total exposure of 1 hour and 4 minutes.

Software: NINA, PHD2, and PixInsight

Clear Skies!

Ernie

NGC 6888 -The Crescent Nebula

 Attack of The Floating Space Brain!!!

Tuesday October 3rd was forecast to be our last clear night for about 2 weeks. Even though it was a work night, decided I had to get out and image something. Fortunately, the Sun is setting earlier, which means we can get some time on targets before it gets too late. Unfortunately, the 82% illuminated Moon would rise around 9 PM. Therefore, I decided to image a bright narrowband target using my L-eXtreme Dual Narrowband filter. The target selected was NGC 6888, The Crescent Nebula. I see a floating space brain. Perhaps I've watched too much sci-fi.

NG6888 - The Crescent Nebula captured on 10/3/2023. Can you spot the Soap Bubble Nebula?

As soon as I got home from work, I set up the telescope. Once it was dark enough, the scope was polar aligned and PHD2 was calibrated. The sequence, created ahead of time, was initiated and the first sub was taken at 8:19 PM. Tuesday night also happened to be the night our astronomy club's (Buffalo Astronomical Association) imaging group was in session. We are called the Tuesday Night imagers (even though we don't always meet on Tuesday). I was imaging from my backyard, so I joined the group at the observatory via Zoom. One of our members advised that I don't need to calibrate PHD2 every time I setup once I have a good calibration. will have to give this a try next time. Will save a little time setting up. May only need to redo calibration if my setup changes. 

I imaged until just a few minutes past midnight, as I would be losing the target to the trees. The Sequence was timed nearly perfectly, the last sub showed a small shadow from the tree. I was already asleep, NINA parked my mount and warmed up the camera. I got up early to retrieve my laptop and put my telescope in the shed. A total of 65 subs were captured at 180 seconds each (Gain 100 / Offset 50).

Processing:

All pre and post processing was performed in PixInsight. Images were reviewed with Blink and the Subframe Selector Process, with a total of 10 images rejected. The 55 remaining subs were loaded in WBPP. Astrometric solution, Autocrop, & 2X Drizzle integration were enabled. Linear: The background was removed with ABE and color calibration was performed with SPCC. The image was deconvolved with BlurXT, noise was reduced with NoiseXT, and the image was stretched with HT. 

Non-linear: The stars were removed with StarXT and here's where things get a little interesting. As a result of a conversation on the Zoom, I decided to try the Narrowband Normalization Process (Cosmic Photons) from Bill Blanshan and Mike Cranfield. Specifically, I used the HOO palate (no choice as i was using a dual narrowband filter with an OSC camera) in Blend 2 mode. This process is amazing (as my friend had indicated in our conversation). The Realtime Preview, sliders, and various selections make it easy to get the best results for your image! Stars: Applied saturation with CT, removed green noise with SCNR, and ran the Correct Magenta Stars script. Starless: Applied multiple iterations of CT to add saturation, increase brightness, and contrast. Applied LHE at 3 different kernel sizes. Applied MMT and DSE. I screened the stars back in with Pixel Math and did some star reduction with Bill Blanshan and Mike Cranfield's Star Reduction process. Finally, the image was down samples to a more manageable size.

What is it?

The Crescent Nebula (NGC 6888) is an emission nebula located in the constellation Cygnus. This object is formed by the strong stelar wind from a Wolf-Rayet star (WR 136). This star is losing its outer layers at the rate of the mass of our Sun every 10,000 years. This massive star is likely to go Supernova some day in a million or so years.

Annotated image of NGC 6888.

How big is it?

This object has an angular distance of 20 x 10 arcminutes (1 degree is 60 arcminutes) on the night sky. The object is 25 light-years (ly) across. 

How far is it?

It is located about 4,700 light-years (ly) from Earth in the Constellation Cygnus.

How to find it?

This object is relatively easy to find. It's very close to the bright star Sadr in the constellation Cygnus. Refer to the finder chart below. 

Finder Chart

Image Details:

Capture Date: 10/03/2023

Location: Eden, NY

Telescope: Explore Scientific ED80 Essential Series Air-Spaced Triplet Refractor

Camera: ZWO ASI2600MC Pro

Filter: Optolong l-eXtreme 

Mount: Sky-Watcher USA EQ6-R Pro

Exposure: 55 exposures at 180 sec / Gain 100 / Offset 50 / -10°C each for a total exposure of 2.75 hours.

Software: NINA, SharpCap Pro, PHD2, and PixInsight

Clear Skies!

Ernie

LDN 1235 - The Dark Shark Nebula

 Smile you Son of a ...

LDN 1235 - The Dark Shark Nebula captured on 9/14/2023 & 9/15/2023

This never happens!!! Two clear nights in a row at New Moon!!! Thursday (9/14) and Friday (9/15) were predicted to be clear, with no Moon. Therefore, wanted to go after something that was a challenge or stretch target for me and my Bortle 4/5 location, The Dark Shark Nebula. This target is very faint and requires dark skies and lots of exposure. I have pretty good skies, around Bortle 4 or 5, darker skies would be better, but figured I would give it a go. 

Wednesday, I framed up the image using Telescopius (telescopius.com) because I wasn't able to find this object in the NINA Sky Atlas. One advantage of Telescopius is that it allows you to adjust the brightness of the image being displayed. Increasing the brightness made the Shark visible, an advantage when framing the image. I imported the coordinates into the NINA Framing Assistant and then created a Sequence so I would be ready to go Thursday night. I still use the Legacy Sequencer, although I'm preparing to give the Advanced Sequencer a try. Will use a night with a bright Moon to experiment (not risking clear nights at New Moon). 

Thursday, after getting home from work, I quickly set up my imaging rig. Things went smoothly. Polar aligned with SharpCap Pro and calibrated the guiding software (PHD2) once skies were dark enough. Started collecting subs at 8:43 PM. Individual 2-minute sub exposures (subs) did not show any hint of the Shark, even with a screen stretch. I decided to keep collecting exposures without a change because I was shooting to the North, there's lots of light pollution to my North. Examining the subs and looking at the histogram led me to the decision to keep exposure as is. My hope was by getting enough exposures, I would be able to get the Shark. I stopped imaging at 2:23 AM, when the target would be lost to the trees. Was able to collect 130 subs on night 1. NINA parked my scope and warmed the camera. I got up earlier the next morning to bring in my laptop and cover my rig with a tarp. 

A single 2-minute exposure (calibrated and debayered) with an unlinked auto stretch applied (no other processing). Do you see the Shark? 

I got a later start on Friday night as I tried (unsuccessfully) to catch Comet C/2023 P1 Nishimura at sunset. Started capturing exposures at 8:54 PM. Conditions were very good again and the imaging session went smoothly. The session ended at 2:31 AM. A total of 139 exposures were captured. NINA parked the scope and warmed the camera. Retrieved my laptop in the morning and waited until late morning to put my equipment away, as everything was covered in dew. Saturday was forecast to be cloudy. Even if it was clear, I would not have been able to image due to family a commitment. 

Image Processing

All pre and post processing was done in PixInsight. All 269 sub exposures were evaluated with Blink and the Subframe Selector process. After this evaluation, 36 sub exposures were discarded. The remaining 233 subs were loaded into the Weighted Batch Pre-Processing Script (WBPP) along with the associated calibration (Darks, Flats, & Flat Darks) frames. This represents a total of 7 hours and 46 minutes of total exposure. I enabled 2X Drizzle Integration. This is the resulting Master Light unlinked auto stretch applied (no other processing). 

Master Light from WBPP. Can you start to see the Shark now?

Linear Processing: Automatic Background Extraction (ABE), Sprectrophotometric Color Calibration (SPCC), RC-Astro's BlurXTerminator (BXT), RC-Astro's NoiseXTerminator (NXT), and the image was made non-linear with Histogram Transformation (HT). 

Non-Linear Processing: RC-Astro's StarXTerminator (SXT). Stars: Saturation was enhanced with Curves Transformation (CT) and Green Noise was removed with SCNR. Starless: Another application of NXT, the Image was brightened, and contrast was enhanced with multiple applications of CT. A mask was applied, and Saturation was enhanced with CT. Mask was removed and SCNR was applied. Local Histogram Equalization (LHE) was applied at 3 different Kernel sizes followed by Multiscale Median Transform (MMT). Dark Structure Enhance script (DSE) was used and the Stars were screened back in with pixel Math. The image was resampled down by 50% with the Resample process (making the file size a little more manageable). The image was processed 6 different times using the above process/scripts with slightly different setting each time, until the final (for now) image at the beginning of this post was obtained.  

What is it?

The Dark Shark is located in a section of the Milky Way that contains a lot of interstellar Dust and Gas. This object is comprised of interstellar dust and gas. Powerful winds radiating from massive stars create the "structure" or shape of this object. 

An annotated version of the image

How big is it?

This Shark is about 15 light-years (ly) from head to tail.

How far is it?

It is located about 650 light-years (ly) from Earth in the Constellation Cepheus.

How to find it?

I'm honestly not sure if this object can be observed visually, if it can be observed, assuming this would be a very challenging target. My gut says this can't be visually observed. This object is located in the Constellation Cepheus. To me, it looks like a house. The Dark Shark Nebula is location is indicted by the red rectangle in the finder chart below. 

Finder Chart for Dark Shark Nebula

Image Details:

Capture Date:09/14/2023 and 09/15/2023

Location: Eden, NY

Telescope: Explore Scientific ED80 Essential Series Air-Spaced Triplet Refractor

Camera: ZWO ASI2600MC Pro

Filter: None

Mount: Sky-Watcher USA EQ6-R Pro

Exposure: 9/14: 104 exposures at 120 sec each; 9/15: 129 exposures at 120 sec each for a total exposure of 7 hours 46 minutes. Gain 100 / Offset 50 / -10°C for both nights.

Software: NINA, SharpCap Pro, PHD2, and PixInsight

Clear Skies!

Ernie

M27 with a Dual Narrowband Filter

A return to M27

Friday September 1st was a clear night, a clear night with a very bright (nearly full) Moon. I decided to use my Optolong L-eXtreme dual narrowband filter on M27. I imaged M27 without a filter under moonless skies back in May (click here for the related post). The L-eXtreme has 7 nm band passes in both Ha and Oiii. It would be interesting to see how it would perform with an almost full Moon. This is the resulting image.

M27 imaged with a dual narrowband filter on 9/1/2023.

Setup went relatively smoothly. Started collecting images at 9:14 PM and stopped at 1:56 PM when clouds started to roll in (I wouldn't have been long until I lost the target to the trees anyways). I collected a total of 52 subs at 300 sec each. All pre and post processing was performed in PixInsight. A total of 45 subs were used after inspecting the frames with blink and using the Subframe Selector process. Processes used: Blink, Subframe Selector, WBPP (enabled2x Drizzle Integration and Autocrop), DBE, SPCC, BlurXTerminator, NoiseXTerminator, HT, and StarXterminator (unscreen stars). Stars: Curve Transformation (saturation), SCNR, and Correct Magenta Stars Script. Starless: Curve Transformation with mask (RGB/K), Curves Transformation with mask (saturation), SCNR, LHE, MMT, and Pixel Math to Screen stars back in. Finally, the image is significantly cropped in as this object is very small in my setup.

What is it?

Messier 27 (M270, also known as the Dumbbell Nebula, is a form of Emission Nebulae known as a Planetary Nebula. It has the distinction of being the first planetary Nebula ever discovered.  A Planetary Nebula is the remnant of a star, like our Sun, that is too small to end its life as a Supernova. Instead, as the star reaches the end of its life, no longer capable of fusion, the star will lose its outer shells. A hot and very dense remnant known as a White Dwarf is left behind. Even though it is no longer capable of fusion, it is hot enough to ionize the expelled shells of gas.

How big is it?

This object has an angular distance of 8.0 x 5.7 arcminutes (1 degree is 60 arcminutes) on the night sky.

How far is it?

It is located about 1,400 light-years (ly) from Earth in the Constellation Vulpecula.

How to find it?

This object is relatively easy to find in a pair of binoculars, optical finder scope, or telescope with a wide field of view. It is located in the Constellation Vulpecula which is a dim constellation located within the Summer Triangle. A nebula filter (like UHC or Oiii) filter can help improve contrast and make the nebula stand out more from the background sky. Use the finder chart below to help you locate it.

1. Find the Summer Triangle (Vega, Deneb, & Altair).
2. Method 1: 
1. Find Albireo (a beautiful visual target itself) which is the head of Cygnus the Swan or the base of the Northern Cross. 
2. Find Altair. 
3. M27 is the vertex of a imaginary triangle with Albireo and Altair as the other two vertices.
3. Method 2: (Darker skies may be required)
1. Find 13 Vulpeculae.
2. Find Gamma Sagittae.
3. M27 is the vertex of a imaginary triangle with 13 Vulpeculae and Gamma Sagittae as the other two vertices.

Finder Chart for M27

Image Details:

Capture Date:09/01/2023

Location: Eden, NY

Telescope: Explore Scientific ED80 Essential Series Air-Spaced Triplet Refractor

Camera: ZWO ASI2600MC Pro

Filter: Optolong l-eXtreme 

Mount: Sky-Watcher USA EQ6-R Pro

Exposure: 45 exposures at 300 sec / Gain 100 / Offset 50 / -10°C each for a total exposure of 3.75 hours.

Software: NINA, SharpCap Pro, PHD2, and PixInsight

Clear Skies!

Ernie

The Coathanger Asterism - A Great Target for Binoculars

 

Things have been a little crazy

It's been a while since I've posted. In addition to poor weather and smoke, the last couple of months have been crazy (both at work and at home). Catching up on the few opportunities I had to image since July.

The Coathanger - captured on 8/19/20232 with the open star cluster NGC 6802 just to the left of the horizontal portion of the Coathanger.

The Coathanger is one of my favorite visual targets, especially for binoculars (this isn't the first target or the last that I will describe in that way). I love to observe with binoculars. I have a pair of 8 x 40 and a pair of 10 x 50. The 8 x 40's are perfect handheld and the 10 x50's are best on a tripod. The Coathanger is located in the Summer Triangle, so it is almost directly overhead at dark. If you're interested in astronomy and don't have a telescope (or even if you do), but have a pair of binoculars, grab them at dark and try finder this object. 

August 19th was a Saturday night. Although clear, the transparency was poor and clouds were predicted later in the night. Only a brief window to image. Knowing the window would be short, figured I would go after The Coathanger as lots of integration time would not be needed. Ended up with 92 subs at 30 secs each. I started collecting subs at 9:55 PM and stopped at 11:23 PM when the clouds became more frequent. I collected 119 subs but had to discard a large number due to passing clouds / poor sky conditions. Given the circumstances, the resulting image isn't that bad. 

What is it?

The Coathanger is known as Collinder 399 (Cr 399) or Brocchi's Cluster. This object is an Asterism (a prominent or recognizable pattern of stars). It is not a true open star cluster, it is a chance alignment of 10 bright stars. There are about 30 more stars that some consider to be a part of the asterism. 

An annotated version of the image of The Coathanger.

How big is it?

This object has an angular distance of 89 arcminutes (1 degree is 60 arcminutes) on the night sky.

How far is it?

It is located about 4,200 light-years (ly) from Earth in the Constellation Vulpecula.

How to find it?

This is object is relatively easy to find in a pair of binoculars, optical finder scope, or telescope with a wide field of view. It is located in the Constellation Vulpecula which is a dim constellation located within the Summer Triangle.  Use the finder chart below to help you locate it.

1. Find the Summer Triangle (Vega, Deneb, & Altair).
2. Method 1: 
1. Find Albireo (a beautiful visual target itself) which is the head of Cygnus the Swan or the base of the Northern Cross. 
2. Find the star Alpha Vulpecula and draw an imaginary line from Albireo through Alpha Vulpecula. The Coathanger is roughly the same distance from Alpha Vulpecula as Alpha Vulpecula is from Albireo. 
3. Method 2:
1. Find Vega and Altair and draw an imaginary line between them.
2. The Coathanger is roughly between both stars (it's a little closer to Altair).

A finder Chart for The Coathanger

Image Details:

Capture Date:08/19/2023

Location: Eden, NY

Telescope: Explore Scientific ED80 Essential Series Air-Spaced Triplet Refractor

Camera: ZWO ASI2600MC Pro

Filter: none

Mount: Sky-Watcher USA EQ6-R Pro

Exposure: 92 exposures at 30 sec / Gain 100 / Offset 50 / -10°C each for a total exposure of 46 minutes.

Software: NINA, SharpCap Pro, PHD2, and PixInsight

Clear Skies!

Ernie

IC 1396 - The Elephant Trunk Nebula - 07/07/2023

 It was an unexpected clear night and a Friday night too!

Clear skies on a Friday night and daylight savings time actually working to my advantage. Noticed potential for clear skies that morning of July 7th but didn't get my hopes up too high. Got home from work, went to dinner, ran a few errands, and got home in plenty of time to setup before dark. Since the Moon was going to rise at midnight, figured it would be good to after an emission nebula so I could try out my L-eXtreme Dual Narrowband filter out with my ZWO ASI2600MC Pro for the first time. Got great results with the filter last year with my DSLR. I decided to shoot IC 1396, The Elephant Nebula in the constellation Cepheus. 

Started capturing 180 sec subs at 10:18 PM and kept going until 4:06AM, when I went outside to take flat frames. Ended up using 79 subs, resulting in a total exposure of 3.95 hours. The image was processed in PixInsight using a Dual Narrowband "SHO" method that was provided to me by a mentor from the Buffalo Astronomical Association. This method approximates the SHO or Hubble Palette color map scheme with data from dual Narrowband filters and one-shot color (OSC) cameras like mine. 

This is the resulting image. 

IC1396 - The Elephant Trunk Nebula from 07/07/2023

What is it?

IC 1396 is a region of ionized interstellar gas and dust that contains smaller regions of concentrated gas and dust that appear as dark knots or globules in visible light images. The gas in the entire region is being ionized by the bright star HD 206267 in the center of the image. The Elephant Trunk Nebula is one of those concentrations of gas and dust. It can be seen rising from the bottom of the image. These areas of concentrated gas and dust, including The Elephant Trunk, are star forming regions. Young stars within The Elephant Trunk were discovered in 2003 using infrared telescopes.

An annotated image of IC 1396, The Elephant Trunk Nebula.

How big is it?

The entire region is hundreds of light years across and spans over 3 degrees on the night sky.

How far is it?

IC 1396 is located about 2,400 light-years (ly) in the Constellation Cepheus.

How to find it?

The constellation Cepheus is located near the bright signpost constellation Cassiopeia. Cepheus is a circumpolar constellation for observers at mid-northern latitudes and above. This means the constellation never sets. It is visible all night, appearing to circle the north celestial pole currently located near the North star, Polaris. to me, this constellation looks like a house with disproportionately large roof. IC 1396 is indicated in the chart by the red rectangle just off what would be the ground floor of the house. 

Finding Chart for IC 1396 (the red rectangle in the center of the chart).

Image Details:

Capture Date:07/07/2023

Location: Eden, NY

Telescope: Explore Scientific ED80 Essential Series Air-Spaced Triplet Refractor

Camera: ZWO ASI2600MC Pro

Filter: Optolong l-eXtreme 

Mount: Sky-Watcher USA EQ6-R Pro

Exposure: 79 exposures at 180 sec / Gain 100 / Offset 50 / -10°C each for a total exposure of 3.95 hours.

Software: NINA, SharpCap Pro, PHD2, and PixInsight

Clear Skies!

Ernie

Markarian's Chain

 A great Galaxy Season target for widefield setups

Those of us with shorter focal length, widefield setups can feel target starved during galaxy season. Galaxies, with a few exceptions, are often small targets, better suited for longer focal length telescopes. Markarian's Chain is a string of galaxies located in the constellation of Virgo, that makes an aesthetically pleasing target for telescopes with a wide field of view. My imagination sees this string of galaxies as a snake like creature with an oversized head sporting a "meh" expression. 

Markarian's chain captured from my backyard on May 15, 2023.

The chain of galaxies includes M86 and M84 as well as a pair of interacting galaxies, NGC 4438 and NGC 4435, known as The Eyes. Not sure why they are called The Eyes, but I see M86 and M84 as a pair of eyes. The prominent elliptical galaxy located in the lower left corner of the image is M87. Please refer to the annotated image below to identify the prominent galaxies contained in this field of view. Please note, this annotation was limited to NGC and IC catalogs, as the resulting annotated image would be overwhelming due to the number of galaxies in this field if other catalogs were included. 

Annotated image of Markarian's Chain. Note: annotation limited to NGC and IC catalogs.

The data for this image was captured on the night of May 15, 2023. The imaging session began at 9:52 PM and was completed at 2:21 AM on the morning of the 16th, when the target was lost to the trees. A total of 102 120 sec sub exposures were captured, of which 65 were used to produce the image. If become more discriminating about the exposures I use to produce images. I use the Blink process and the "SubframeSelector" process in PixInsight to remove exposures with undesirable characteristics (poor focus, eccentric stars, low signal weight, etc...) due to various factors like passing clouds. I have found being more discriminating about the individual subs for the image has been producing better results. This is my third attempt at processing this data. Since we have not had any good conditions for imaging since late May, I have had plenty of time to process data lurking in my hard drive.

What is it?

Markarian's Chain is a string of galaxies located in the constellation of Virgo that forms part of the Virgo Cluster of galaxies. The chain of galaxies is named after soviet astrophysicist, Benjamin Markarian, who discovered that at least seven of the galaxies in the chain move coherently. 

How big is it?

The field of view of this image is roughly 2.8 degrees by 1.9 degrees. 

How far is it?

The prominent galaxies in this image (M84, M86, and The Eyes) are located about 50 million light-years (50Mly) from Earth.

How to find it?

Unfortunately, as the publishing of this post, Markarian's Chain can be found low in the western sky. This target is best viewed during spring in the northern hemisphere. Markarian's Chain is located in the "bowl" of the constellation Virgo. Refer to the finder chart below. I use the two stars at the top of the bowl and Denebola, the star that marks the tail of Leo the Lion, to triangulate its position. 

Finding Chart for Markarian's Chain.

Image Details:

Capture Date:05/15/2023

Location: Eden, NY

Telescope: Explore Scientific ED80 Essential Series Air-Spaced Triplet Refractor

Camera: ZWO ASI2600MC Pro

Filter: None

Mount: Sky-Watcher USA EQ6-R Pro

Exposure: 65 exposures at 120 sec / Gain 100 / Offset 50 / -10°C each for a total exposure of 2.2 hours.

Software: NINA, SharpCap Pro, PHD2, and PixInsight

Clear Skies!

Ernie