NGC 6995 The Bat Nebula clearly visible expansion over 68 years
Posted: Thu Sep 23, 2021 6:22 pm
NGC 6995 (The Bat Nebula) is a part of the Veil Nebula.
Capture and video showing a very clear expansion of the nebula over 68 years.
I captured it for 2 hours last night and like usual I did compare my stacked capture in Aladin but also with a capture from https://archive.stsci.edu/cgi-bin/dss_form and the the POSS1 Blue capture from 1953 made with the 18 inch Mount Palomar Schmidt telescope.
When layering my capture and the Palomar capture in Photoshop, there were some proper motion stars as expected but the movement of the nebula was the big surprise.
I first though that was because I captured in dual narrowband and the Palomar one was done with a broadband blue filter. But the movement was too big for that.
Did some searching and learned that this expansion first was observed by the Hubble telescope which took images between 1997 and 2015, an 18 years period. Also, this expansion happens at a velocity of about 1.5 million kilometers (932057 miles) per hour.
Ergo: the movement I did see is real
So of course I had to make it as video. Besides the Hubble one, I couldn't find anything similar, so I think it's a kind of first?
Video is best observed in full. Note: it looks like everything is moving but that's an optical illusion: the stars stay on one place and the nebula moves.
Here the video:
https://youtu.be/a9BFnjciq90
And of course also the colored capture itself below.
Bortle 6/7
Meade LX200 8" f/10 ACF OTA
Ioptron CEM25EC montering (no guiding)
Optolong L-eXtreme filter
Zwo ASI071MC Pro camera
Captured with SharpCap Pro @ -10 Celsius / White balance R50 B50
12 x 600 sec / Gain 90 / Offset 20)
20 x darks, 50x flats en 50x darkflats
Stacked with DeepSkyStacker
Processed in SiriL and Photoshop
Siril: Crop and Histogram Transformation
Photoshop: Levels, Curves, Camera Raw Filter (blacks, clarity, sharpening, color, nose reduction) en nog wat bewerkingen. Resize 5000 to 2000px
Capture and video showing a very clear expansion of the nebula over 68 years.
I captured it for 2 hours last night and like usual I did compare my stacked capture in Aladin but also with a capture from https://archive.stsci.edu/cgi-bin/dss_form and the the POSS1 Blue capture from 1953 made with the 18 inch Mount Palomar Schmidt telescope.
When layering my capture and the Palomar capture in Photoshop, there were some proper motion stars as expected but the movement of the nebula was the big surprise.
I first though that was because I captured in dual narrowband and the Palomar one was done with a broadband blue filter. But the movement was too big for that.
Did some searching and learned that this expansion first was observed by the Hubble telescope which took images between 1997 and 2015, an 18 years period. Also, this expansion happens at a velocity of about 1.5 million kilometers (932057 miles) per hour.
Ergo: the movement I did see is real
So of course I had to make it as video. Besides the Hubble one, I couldn't find anything similar, so I think it's a kind of first?
Video is best observed in full. Note: it looks like everything is moving but that's an optical illusion: the stars stay on one place and the nebula moves.
Here the video:
https://youtu.be/a9BFnjciq90
And of course also the colored capture itself below.
Bortle 6/7
Meade LX200 8" f/10 ACF OTA
Ioptron CEM25EC montering (no guiding)
Optolong L-eXtreme filter
Zwo ASI071MC Pro camera
Captured with SharpCap Pro @ -10 Celsius / White balance R50 B50
12 x 600 sec / Gain 90 / Offset 20)
20 x darks, 50x flats en 50x darkflats
Stacked with DeepSkyStacker
Processed in SiriL and Photoshop
Siril: Crop and Histogram Transformation
Photoshop: Levels, Curves, Camera Raw Filter (blacks, clarity, sharpening, color, nose reduction) en nog wat bewerkingen. Resize 5000 to 2000px