Jump to content

NGC1491


Jkulin
 Share

Recommended Posts

I've been really snowed under with work, but yesterday decided to make or break my capture of NGC1491.

I have been trying to get sufficient data since November, but clumsily I kept knocking my camera's rotation, enough that at a 2000mm focal length that I could not get the orientation how I wanted it, so yep I have thrown away 20 hours of data! ? 

The good news is that I had captured nearly another 20 hours of data, grabbing an hour or two over various night, the Pixinsight WBPP script didn't want to know about stacking, so it was back to basics and compile manually.

From Bortle 5/6 Skies, I am happy how it has turned out and I am glad I persevered.

Taken with Altair/GSO 10" Truss RC, Moravian G2-8300 MkII CCD, Ultrastar Guiding, iOptron 120EC Mount, Pegasus UPB & Focuser, Chroma 2" Filters.

You can view more details here: - https://www.astrobin.com/0rbknn/B

Dates:Jan. 9, 2021Jan. 20, 2021Jan. 22, 2021Jan. 25, 2021

Frames:
Chroma Blue 2" unmounted: 8x396" -20C bin 1x1
Chroma Green 2" unmounted: 8x300" -20C bin 1x1
Chroma Ha 3nm: 19x1200" -20C bin 1x1
Chroma OIII 3nm: 20x1200" -20C bin 1x1
Chroma Red 2" unmounted: 8x348" -20C bin 1x1
Chroma SII 3nm: 11x1200" -20C bin 1x1

Integration: 19.0 hours

Now for the Bumf: -

NGC 1491 (also designated SH2-206 and LBN 704) is a bright emission nebula and HII region, located on the edge of a vast cloud region of neutral gas, about 10,700 light-years away in the Perseus arm of our Milky Way Galaxy in the constellation Perseus.

HII regions are well known for being places where new stars are born, and are created when ultraviolet radiation from hot stars ionizes the surrounding gas, causing it to glow in visible light. The surrounding dust is also heated by this radiation, so we also see it glow in infrared light.

The blue 11.22 magnitude star (BD +50 ° 886) is illuminating the nebula while its strong stellar wind is “blowing” a bubble in the gas that immediately surrounds it. The intense radiation from the star is also eroding the gas clouds surrounding it.

The entire nebula is quite irregular with a subtle bite cut out of the nebulosity from the east side that creates a darker hollow, and a high surface brightness region — as seen in this image — preceding the star. A faint, elongated haze extends from this patch to the north-east past the star giving an elongated appearance.

  • Like 6
Link to comment
Share on other sites

Posted by: @Jkulin

I've been really snowed under with work, but yesterday decided to make or break my capture of NGC1491.

I have been trying to get sufficient data since November, but clumsily I kept knocking my camera's rotation, enough that at a 2000mm focal length that I could not get the orientation how I wanted it, so yep I have thrown away 20 hours of data! ? 

The good news is that I had captured nearly another 20 hours of data, grabbing an hour or two over various night, the Pixinsight WBPP script didn't want to know about stacking, so it was back to basics and compile manually.

From Bortle 5/6 Skies, I am happy how it has turned out and I am glad I persevered.

Taken with Altair/GSO 10" Truss RC, Moravian G2-8300 MkII CCD, Ultrastar Guiding, iOptron 120EC Mount, Pegasus UPB & Focuser, Chroma 2" Filters.

That's a bummer losing all that data John, but it turned out great in the end.

I have never used the WBPP script or the BPP script, I prefer the manual approach, then if anything does go wrong, it can be traced back to the culprit.

Brian

Link to comment
Share on other sites

@astronomyukraine

Hi Brian,

This is not the first or last time that I think that the WBPP script fails.

I noticed that the the darks are not fully subtracted from the lights, which I think means that some of the noise is being treated as stars.

I'm getting old some my memory is not as good as many, but when this happens I always go back and follow Warren Kellers book star alignment and it hasn't failed yet.

Its a bit more long winded but the stacking seems much more reliable.

Link to comment
Share on other sites

Posted by: @Jkulin

Hi Brian,

This is not the first or last time that I think that the WBPP script fails.

I noticed that the the darks are not fully subtracted from the lights, which I think means that some of the noise is being treated as stars.

I'm getting old some my memory is not as good as many, but when this happens I always go back and follow Warren Kellers book star alignment and it hasn't failed yet.

Its a bit more long winded but the stacking seems much more reliable.

Hi John. Adam Block has a full tutorial series about the WBPP script. It is a series of 10 videos, around 3 hours in total. It is a very in-depth look at WBPP. It might help solve your problems.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...