NGC 2237 - The Rosette Nebula (Skull Orientation)

This target was way too close to the nearly Full Moon ...

The night of February 20th was just a few days before The Full Moon (2/24). Even worse, this bright Moon was in the Constellation Gemini. This meant the Moon was very close to that night's target, The Rosette Nebula. Well, I wanted to see just how well the Optolong L-eXtreme Dual Narrowband filter would perform under these unfair circumstances. Spoiler alert, it wasn't great, but it wasn't a total loss.

I got home from work and setup my rig. As we are approaching spring, it is staying light noticeably later. This takes a little pressure off when getting setup (nothing worse than setting up under a clear dark sky). It still gets dark early enough to get a decent amount of imaging before it is too late. This will change as Spring turns towards Summer. I started collecting subs (short for sub-exposures) at 7:11 PM and stopped at 10:00 PM due to clouds. Exposure time was 180 sec each at Gin 100 / Offset 50 / -10 deg C. Ended up using 44 subs (2.2 hours total exposure) to produce the image. I oriented the object to show the Skull. Please note, there is a separate deep sky object called the Skull Nebula. My daughter is a Radiology Technician and has always had a fascination with bones, skeletons, and skulls. So, I guess this is in her honor.

NGC 2237 - The Rosette Nebula. Do you see the skull?

So, what about that Moon thing? Well, it was an issue. The image below is a single exposure (sub) with Boosted Auto Stretch applied. Thankfully we have many capable tools to deal with Gradients. No doubt this gradient impacted the processing of the image, but I'm pleased with how it ended up after processing. 

Single exposure showing Gradient from the Moon.

Processing:

I did all pre and post processing in PixInsight. Pre-processing: Blink & WBPP. Linear Post-processing: Dynamic Background Extraction (DBE - see next paragraph), BlurXTerminator (correct only), Spectrophotometric Color Calibration, BlurXTerminator, NoiseXTerminator, and Histogram Transformation. Non-Linear Post-processing: StarXTerminator. Starless: Narrowband Normalization (simulated SHO), 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 two different methods of Gradient removal. Specifically, DBE, GraXpert, and the new Gradient correction process. To my eye DBE gave me the best result. GraXpert removed too much nebula and the new Gradient Correction Tool did not seem to work well with this image. Note: This is a new tool so it could also be that I did not apply it in the optimal manner.

What is it?

The Rosette Nebula contains multiple deep sky objects, including bright nebulosity and a star cluster (NGC 2244). NGC 2237 usually denotes the whole nebula. Other objects contained in the area include NGC 2238, NGC 2239, & NGC 2246. The nebula is in the constellation Monoceros. The Nebula has a circular pattern that resembles a flower. However, it can be oriented (as shown in my images) in a way that resembles a Skull. As indicated above there is an entirely separate deep sky object known as the Skull Nebula (NGC 246).

This object is an emission nebula. Stellar winds from the hot, large, and young stars in the star cluster have carved out the central area. These stellar winds also exert pressure on the remaining gas and dust. This leads to star formation, which is actively occurring in the nebula. 

How Big is it?

This object has an apparent size of 80 by 60 arcminutes (1 degree is 60 arcminutes) on the night sky. It is 128 light-years (ly) in diameter.

How Far is it?

It is located about 5,500 light-years (ly) from Earth in the Constellation Monoceros.

How to find it?

This object is easier to photograph than visually observe. To visually observe you will need requires dark skies and good seeing conditions, specifically transparency. A wide field telescope with a large field of view is required to see the entire object, as it is 5 times the size of the Full Moon in the sky. Large telescopes (over 8 inches) can reveal the dark nebulosity contained with the object.

Even though the constellation Monoceros is relatively dim, this object is relatively easy to locate. It is roughly halfway between the bright stars Betelgeuse (in Orion) and Procyon (in Canis Minor) as indicated in the finder chart below.

Image Details:

Capture Date: 02/20/2024

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: 44 exposures at 180 sec / Gain 100 / Offset 50 / -10°C each for a total exposure of 2 hour and 12 minutes.

Software: NINA, SharpCap Pro, PHD2, and PixInsight

Clear Skies!

Ernie

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

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

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

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