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#1
Astrophotography / Re: Rho Ophiuchi Cloud Complex
Last post by Dave A - May 17, 2025, 15:00:21Lovely image Robert
The colours are great
The colours are great
#2
Astrophotography / Re: Rho Ophiuchi Cloud Complex
Last post by Carole - May 17, 2025, 10:42:17Lovely Robert, one of my favourite targets. However unlike you, it took me 2 trips to Spain and 2 trips to DSC to get anything decent, spread over 6 years.
A nice lot of information there, I will attempt to summarise at Members images.
I remember your previous Rho Ophiuchi Cloud Complex from a fair few years ago, this is a step up from that one.
I am always fascinated by the bit that joins the Antares Nebula to the Rho Ophiuchi nebula with that "pinched" appearance. It took me some years to realise that is in fact dark nebulosity causing that pinched look. I can see it quite well on your image.
Carole
A nice lot of information there, I will attempt to summarise at Members images.
I remember your previous Rho Ophiuchi Cloud Complex from a fair few years ago, this is a step up from that one.
I am always fascinated by the bit that joins the Antares Nebula to the Rho Ophiuchi nebula with that "pinched" appearance. It took me some years to realise that is in fact dark nebulosity causing that pinched look. I can see it quite well on your image.
Carole
#3
Astrophotography / Rho Ophiuchi Cloud Complex
Last post by RobertM - May 16, 2025, 18:30:28This is probably the most colourful part of the whole sky and is my second image with the little Askar SQA55 from Isla Palma.
Larger
4k
Full size 6k
A crop of M4 Globular cluster from the image with a bit less stretch:
There's obviously a lot going on in this colourful part of the sky:
This area of the sky is mostly in the constellation of Scorpious however the top right quadrant is in the constellation of Ophiuchus. The whole complex is one of the closest star forming regions to us.
1. To the top left quadrant is Antares and the associated orange nebula complex it illuminates. The star is a red giant of about 15 solar masses and is actually one of the largest stars visible to the naked eye, it's diameter puts its surface out at about the asteroid belt (if centred on the sun)!
2. The right middle quadrant contains the blue subgiant star Rho Ophiuchi (brighter of the three) and the blue nebula lit up by it's emissions.
3. Imbedded in the Antares nebula is the blue reflection nebula IC4605 illuminated by the hot blue star 22 Scorpii.
4. To the bottom left of middle is the multiple star system Sigma Scorpii surrounded by both emission and reflection nebula ionised by the star. Also called the Sigma Scorpii nebula the official designation is Sh2-9.
5. Just right of centre is the reflection nebula IC4603 which is primarily illuminated by the intense UV radiation of the hot young star HD147889. There is also a slightly reddish tint caused excited Ha emissions.
6. In the lower left is the M4 Globular cluster. This cluster is about 75 light years across and 6,000 light years away making it visually the same size as the full moon. It is also notable as the first globular cluster where individual stars were resolved. You can also see the faint dust lane present in most globulars.
7. In the lower right hand corner is M80, which is 20% larger than M4 but also over five times further away, it is also one of the densest of the Milky Way globulars. A lot of the stars in the cluster are metal deficient indicating very old stars (perhaps 10 billion years or more).
Capture details:
Location: Puntagorda, Islas La Palma
Telescope: ASKAR SQA55
Camera: ASI2600MC Duo
Filter: Player One UV/IR cut
Mount: ZWO AM3
Capture hardware ASIAir Plus
SubExposures: 19 x 300s
Larger
4k
Full size 6k
A crop of M4 Globular cluster from the image with a bit less stretch:
There's obviously a lot going on in this colourful part of the sky:
This area of the sky is mostly in the constellation of Scorpious however the top right quadrant is in the constellation of Ophiuchus. The whole complex is one of the closest star forming regions to us.
1. To the top left quadrant is Antares and the associated orange nebula complex it illuminates. The star is a red giant of about 15 solar masses and is actually one of the largest stars visible to the naked eye, it's diameter puts its surface out at about the asteroid belt (if centred on the sun)!
2. The right middle quadrant contains the blue subgiant star Rho Ophiuchi (brighter of the three) and the blue nebula lit up by it's emissions.
3. Imbedded in the Antares nebula is the blue reflection nebula IC4605 illuminated by the hot blue star 22 Scorpii.
4. To the bottom left of middle is the multiple star system Sigma Scorpii surrounded by both emission and reflection nebula ionised by the star. Also called the Sigma Scorpii nebula the official designation is Sh2-9.
5. Just right of centre is the reflection nebula IC4603 which is primarily illuminated by the intense UV radiation of the hot young star HD147889. There is also a slightly reddish tint caused excited Ha emissions.
6. In the lower left is the M4 Globular cluster. This cluster is about 75 light years across and 6,000 light years away making it visually the same size as the full moon. It is also notable as the first globular cluster where individual stars were resolved. You can also see the faint dust lane present in most globulars.
7. In the lower right hand corner is M80, which is 20% larger than M4 but also over five times further away, it is also one of the densest of the Milky Way globulars. A lot of the stars in the cluster are metal deficient indicating very old stars (perhaps 10 billion years or more).
Capture details:
Location: Puntagorda, Islas La Palma
Telescope: ASKAR SQA55
Camera: ASI2600MC Duo
Filter: Player One UV/IR cut
Mount: ZWO AM3
Capture hardware ASIAir Plus
SubExposures: 19 x 300s
#4
Astrophotography / Re: IC4592 (the Blue horsehead...
Last post by RobertM - May 16, 2025, 18:08:51Thank you Carole
#5
Astrophotography / Re: M94
Last post by JohnH - May 12, 2025, 07:24:58I am very happy with "reasonable results of targets otherwise likely impossible"! 
John
John
#6
Astrophotography / Re: M94
Last post by Carole - May 09, 2025, 16:54:46It is certainly experimental but gets you reasonable results of targets otherwise likely imossible with conventional LRGB.
Carole
Carole
#7
Astrophotography / M94
Last post by JohnH - May 09, 2025, 13:04:44M94 is known as The Cat's Eye Galaxy or The Crocodile's Eye Galaxy.
FOV - 28' x 28' (Cropped from approximately 160' x 100')
Total imaging time 13 hours 27 minutes.
Processing: Pixinsight, GraXpert and Affinity Photo 2
This time I varied my processing slightly, Luminance is *just* Dual Band (Ha Oiii) - 5 hours 20 minutes.
Chrominance:
R - 1 hour 28 minutes
G - 1 hour 28.5 minutes
B - 1 hour 30 minutes
Ha - 3 hours 40 minutes
(Any disparity in totals due to rejected subframes)
Telescope - Sharpstar 15028 HNT
Camera - ZWO ASI1600MM Pro (monochrome -cooled to -10C)
Mount - iOptron CEM25P
Assorted ZWO gubbins - Electronic Focus, Filterwheel, Guide camera and telescope and ASIAir Pro.
Location: Bromley (Bortle 7)
I posted this image with an explanation of why I use a Dual Band filter for Luminance and how I use it on Astrobin. The general consensus from experts (Carole dissenting
) seems to be that I am totally wrong and that I will miss too much detail and too much of the spectrum and that I should use very short UV/IR filter images and remove the gradient from each one before integrating. For the moment I am happy to continue with what I am doing. As far as I am concerned it is a hybrid Broadband/Narrowband image (akin to using a Dual Band filter with an OSC camera) and goes a long way to defeating light pollution.
One thing I could, I suppose, is to create a "pseudo Luminance" from RGB and use that to create the star layer. That could give me better star colour.
I look forward to trying it out on nice big nebulae when the nights begin to get darker.
Regards,
John
FOV - 28' x 28' (Cropped from approximately 160' x 100')
Total imaging time 13 hours 27 minutes.
Processing: Pixinsight, GraXpert and Affinity Photo 2
This time I varied my processing slightly, Luminance is *just* Dual Band (Ha Oiii) - 5 hours 20 minutes.
Chrominance:
R - 1 hour 28 minutes
G - 1 hour 28.5 minutes
B - 1 hour 30 minutes
Ha - 3 hours 40 minutes
(Any disparity in totals due to rejected subframes)
Telescope - Sharpstar 15028 HNT
Camera - ZWO ASI1600MM Pro (monochrome -cooled to -10C)
Mount - iOptron CEM25P
Assorted ZWO gubbins - Electronic Focus, Filterwheel, Guide camera and telescope and ASIAir Pro.
Location: Bromley (Bortle 7)
I posted this image with an explanation of why I use a Dual Band filter for Luminance and how I use it on Astrobin. The general consensus from experts (Carole dissenting
) seems to be that I am totally wrong and that I will miss too much detail and too much of the spectrum and that I should use very short UV/IR filter images and remove the gradient from each one before integrating. For the moment I am happy to continue with what I am doing. As far as I am concerned it is a hybrid Broadband/Narrowband image (akin to using a Dual Band filter with an OSC camera) and goes a long way to defeating light pollution.One thing I could, I suppose, is to create a "pseudo Luminance" from RGB and use that to create the star layer. That could give me better star colour.
I look forward to trying it out on nice big nebulae when the nights begin to get darker.
Regards,
John
#8
Astrophotography / Re: IC4592 (the Blue horsehead...
Last post by Carole - May 09, 2025, 10:16:36I've replaced with this new version on Members Images.
#9
Astrophotography / Re: IC4592 (the Blue horsehead...
Last post by RobertM - May 09, 2025, 10:08:12Thanks all
I've added a touch more saturation to this version to bring out the brown dust a bit more:
Larger
4k
Full Monte
I've added a touch more saturation to this version to bring out the brown dust a bit more:
Larger
4k
Full Monte
#10
Astrophotography / Re: More from Petts Wood - Lat...
Last post by Rick - May 08, 2025, 14:45:59Quote from: Roberto on May 08, 2025, 05:55:15I don't know why it doesn't work in this forum anymore.The image included in the post is a .jpg (which doesn't support animation) but the main image of AstroBin is a .gif (which does).