Thursday, February 8, 2024

A Tale of Two Supernovae ... Part 1

 Saturday Night at the Observatory

It has been several months since we have had a clear night. It was clear Saturday night 2/3/2024 into Sunday morning 2/4/2024. Our Astronomy club’s imaging group assembled at our Dark Sky Observatory. We call ourselves the Tuesday Night Imagers, but Tuesday night can be any night of the week.  We put my camera (ZWO ASI2600MC Pro) on the club’s Celestron 14” Edge HD Telescope which is on an Astro Physics AP-1200 mount. An Optolong L-eXtreme Dual-Narrowband filter was used to target specific wavelengths of light.

The imaging team (for the club's equipment) was our Observatory Director (Dan), a member named Mike, and me. Our target was Messier 1 (M1) a.k.a. The Crab Nebula. M1 is a supernova remnant located in the constellation Taurus. We lost some time at the beginning of the night getting things running. The Observatory had not been used (due to poor weather) since mid-December. Programs and drivers needed to be updated and we needed to fine tune the Acquisition software for this new Telescope/Camera combination. We started to acquire images at 8:40 PM and imaged until 11:30 PM when we lost M1 to the Muck near the horizon and the trees. We closed the roof and took our flat frames. Mike removed his camera from the Tele Vue NP-10is that rides on the mount with the 14" Edge HD. We replaced it with an eyepiece to keep things close to balance so Dan and I could go after one more target. We'll cover that in part 2.

We did encounter an issue with aberrations (spikes) on our stars. We were unable to resolve the issue Saturday night. Dan and Mike returned to the observatory Monday evening, and I joined them via Zoom. After some troubleshooting, we believe the issue is caused by the Celestron Dew Heater Ring. Even with the Star spike issue, we managed to collect 13 usable subs at 600 sec each for a total exposure of 130 minutes. Here is the resulting image:

M1, The Crab Nebula from 2/3/2024, HOO version. BAA Tuesday Night Imagers.

Processing:

I did all pre and post processing in PixInsight. Pre-processing: Blink & WBPP. Linear Post-processing: GraXpert, BlurXTerminator (correct only), Spectrophotometric Color Calibration, BlurXTerminator, NoiseXTerminator, and Histogram Transformation. Non-Linear Post-processing: StarXTerminator. Starless: Narrowband Normalization (two methods as described below), Curves (Multiple iterations to increase brightness, contrast, and color saturation), SCNR, Local Histogram Equalization, Unsharp Mask, and Multiscale Median Transform. Stars: Curves (to increase color saturation) and SCNR. PixelMath was used to screen the stars back in. 

I tried to different methods in the Narrowband Normalization process. Method 2 which produces an HOO result and Method 1, which produces a result that simulates the Hubble or SHO palette. The image above is the HOO version. I prefer this version. Here is the simulated SHO version:

M1, The Crab Nebula, simulated SHO Version. BAA Tuesday Night Imagers.

What is it?

M1 is a supernova remnant. Humans observed the Supernova when it occurred in 1054. It was recorded by Chinese astronomers, and it appears that the event is also depicted in Petroglyphs in Arizona and New Mexico. The Chinese astronomers referred to it as a "Guest Star". it was visible during the day for 23 days and was visible at night for 653 days. The supernova also left behind a stellar remnant known as a Pulsar. The Crab Pulsar rotates 30.2 times per second. The nebula is expanding at a rate of 1,800 km/sec.

Annotated image of M1, The Crab Nebula. 

How big is it?

This object has an angular distance of 6 x 4 arcminutes (1 degree is 60 arcminutes) on the night sky. The object is 13 x 11 light-years (ly) across. 

How far is it?

It is located about 6,300 light-years (ly) from Earth in the Constellation Taurus.

How to find it?

This object is relatively easy to find. It's very close to the bright star Zeta Tauri in the constellation Taurus. Refer to the finder chart below. This is a great visual target. It can be seen in binoculars and small telescopes. Dark skies help as it is it can get lost in light polluted skies. Larger aperture helps significantly. Although visible in smaller instruments, I believe it is far more interesting to observe in large aperture scopes. Nebula filters can aid in viewing this object.

      Finder Chart for M1.

      Image Details:

      Capture Date: 02/03/2024
      Location: Beaver Meadow Observatory (North Java, NY)
      Telescope: Celestron 14" Edge HD w/0.7x Reducer
      Camera: ZWO ASI2600MC Pro
      Filter: Optolong l-eXtreme 
      Mount: Astro Physics AP-1200
      Exposure: 13 exposures at 600 sec / Gain 100 / Offset 50 / -10°C each for a total exposure of 130 minutes (2.2 hours)
      Software: NINA, PHD2, and PixInsight


      Clear Skies!
      Ernie

      Tuesday, December 26, 2023

      Starting to share my images through YouTube

       No VLOGs for now

      Starting at after Christmas, I will be trying something new. I will be sharing my Astro Photos through YouTube, in addition to the methods of sharing I use now. As of the time of this blog post (late December 2023) I don't have any intention to create VLOG style videos. I will concentrate on slide show type videos, both in long form and the short form portrait videos that all the rage with the kids these days (clearly I watched too much David Letterman in college). 

      Let the "Year in Review" retrospectives commence:

      The first video will be a slide show of the images captured during 2023. I managed to capture 14 images in 2023. Lots of clouds and smoke. Other than one week in May, when I managed to image five nights in one week, I averaged about one night per month. Happy with the progress I've been making. I've benefited significantly from the experience of members of the Buffalo Astronomical Association, PixInsight classes at Masters of PixInsight, and Astrophotography community at Astroworld

      A collage of my Astro Photos from 2023

      A link to my Youtube Channel (http://www.youtube.com/@Erniej270) has been placed on the home page for this blog. Here's the "First" video: https://youtu.be/s2teiVHLWK0



      I will also be releasing each image as "Short". The first one is of Comet c/2022 E3 (ztf). Here's a link to the at video too: https://youtube.com/shorts/CsAdih8ufRw?feature=share

      Which images from 2023 do you like the best? Leave a comment and let me know. 

      Clear Skies!
      Ernie

      Sunday, December 17, 2023

      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

          Wednesday, October 11, 2023

          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

              Sunday, September 24, 2023

              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

              Saturday, September 16, 2023

              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


              Sunday, September 10, 2023

              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

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              M8, M20, and friends from the farm across the street

               Imaging in the heart of the Milky Way ... I have not imaged with my home rig for several months. Been imaging with the club's scopes at...