Hemisphere:  Northern  ·  Constellation: Cassiopeia (Cas)  ·  Contains:  Bubble Nebula  ·  NGC 7635
Getting plate-solving status, please wait...
NGC 7635 the Bubble Nebula in Cassiopeia, 



    
        

            Mark Wetzel
NGC 7635 the Bubble Nebula in Cassiopeia
Powered byPixInsight

NGC 7635 the Bubble Nebula in Cassiopeia

Getting plate-solving status, please wait...
NGC 7635 the Bubble Nebula in Cassiopeia, 



    
        

            Mark Wetzel
NGC 7635 the Bubble Nebula in Cassiopeia
Powered byPixInsight

NGC 7635 the Bubble Nebula in Cassiopeia

Technical card

Imaging telescopes or lenses: Celestron C9.25 Edge HD

Imaging cameras: ZWO ASI 1600MM-Pro Cool

Mounts: Celestron CGEMⅡ

Guiding telescopes or lenses: Celestron C9.25 Edge HD

Guiding cameras: ZWO 174MM Mini

Focal reducers: Celestron 0.7x Focal Reducer

Software: Celestron CPWI  ·  Main Sequence Software Seqence Generator Pro 3  ·  Pleiades Astrophoto PinInsight  ·  Adobe Photoshop CC 2021 Photoshop 2021  ·  PHD 2

Filters: ZWO 36mm 7nm OIII  ·  ZWO 36mm 7nm Ha  ·  ZWO 36mm 7nm SII  ·  ZWO 36mm Red  ·  ZWO 36mm Green Filter  ·  ZWO 36mm Blue Filter

Accessory: Celestron OAG


Dates:Oct. 22, 2020Nov. 10, 2020Nov. 11, 2020Nov. 12, 2020Nov. 13, 2020Nov. 14, 2020

Frames:
ZWO 36mm 7nm Ha: 80x300" (6h 40') (gain: 139.00) -10C bin 1x1
ZWO 36mm 7nm OIII: 86x300" (7h 10') (gain: 139.00) -10C bin 1x1
ZWO 36mm 7nm SII: 77x300" (6h 25') (gain: 139.00) -10C bin 1x1
ZWO 36mm Blue Filter: 65x120" (2h 10') (gain: 139.00) -10C bin 1x1
ZWO 36mm Green Filter: 57x120" (1h 54') (gain: 139.00) -10C bin 1x1
ZWO 36mm Red: 44x120" (1h 28') (gain: 139.00) -10C bin 1x1

Integration: 25h 47'

Darks: ~50

Flats: ~50

Flat darks: ~50

Avg. Moon age: 23.05 days

Avg. Moon phase: 17.25%

Bortle Dark-Sky Scale: 4.33


Basic astrometry details

Astrometry.net job: 4158672

RA center: 23h 20' 42"

DEC center: +61° 11' 45"

Pixel scale: 0.912 arcsec/pixel

Orientation: 161.441 degrees

Field radius: 0.251 degrees


Resolution: 1575x1200

Locations: Casitas de Gila, Gila, New Mexico, United States; Mesa, Mesa, AZ, United States

Data source: Traveller

Description

Casitas de Gila, Gila, New Mexico and Mesa, Arizona
October 22, November 10-14, 2020

I started imaging the Bubble Nebula in New Mexico in October and finished it in Arizona in November. NGC 7635 was captured with narrowband filters, Hydrogen-alpha (Ha), Oxygen-III (OIII) and Sulfur-II (SII). This is a false color image is combination of 80% Ha and 20% SII in the red channel, 20% SII and 80% OIII in the green channel and 150% OIII in the blue channel using the SHO-AIP multichannel combination script in PixInsight. Red, Green and Blue filter data were obtained to create a star color image that was combined with the false color nebula image.

NGC 7635 is a large emission nebula in the constellation Cassiopeia. The bubble formed when the hot, young central star blew out gas into a “bubble” shape. The elongated bubble is about 10 light years across. NGC 7635 is about 11,000 light years from Earth (SkySafari Pro).

This object was a real challenge for me, and I am not satisfied with the result. First, I discovered that the ZWO ASI 1600MM Pro camera has a defect with the sensor protection cover. The cover reflects light from the sensor back to the sensor to form reflection/diffraction rings around bright stars. This appeared in the OIII, Green and Blue filter data. I attempted to remove the artifacts with the clone stamp. Also, a large halo appeared around the brightest star in the Green and Blue filter data. The details in the bubble are not as sharp as they should be. Finally, I could not get the colors right in a Hubble Pallet SHO image. So, I created a red image by putting Ha and some SII in the red channel, some SII and OIII in the green channel and OIII in the blue channel. Later I did produce a Hubble pallet image using the ColorMask script that has the color combination I was looking for. I will return to this image later in Oregon’s rainy season to sharpen the details.

Comments