trio in Grus

[atalas]

Very nice Ray

[Slawomir (Suavi)]

Originally Posted by Shiraz

Thanks Suavi. I hadn't noticed that small object, but it shows up in both of our images - guess it could be a PN, or maybe a distant starburst galaxy with the UV red-shifted into the blue.

Hi Ray

I looked this object up. It is a galaxy. Below are the coordinates and a bit of info about this galaxy:

Object name: LCRS B231626.6-422158
Co-ordinates: 23h19m11.5s -42d05m33s
Object type: Galaxy
Velocity: 16114 (km/s)
Red shift: 0.053750
Magnitude: 16.13


Cosmology-Corrected Quantities [Ho = 73.00 km/sec/Mpc, Ωmatter = 0.27, Ωvacuum = 0.73]
[Redshift 0.052940 as corrected to the Reference Frame defined by the 3K Microwave Background Radiation]
Luminosity Distance : 226 Mpc (m-M) = 36.77 mag
Angular-Size Distance : 204 Mpc (m-M) = 36.55 mag
Co-Moving Radial Distance : 215 Mpc (m-M) = 36.66 mag
Co-Moving Tangential Dist. : 215 Mpc (m-M) = 36.66 mag
Co-Moving Volume : 0.0417 Gpc^3
Light Travel-Time : 0.684 Gyr
Age at Redshift 0.052940 : 12.615 Gyr
Age of Universe : 13.299 Gyr
Scale (Cosmology Corrected): 990 pc/arcsec = 0.990 kpc/arcsec = 59.41 kpc/arcmin = 3.56 Mpc/degree
Surface Brightness Dimming : Flux Density per Unit Area = 0.81355; Magnitude per Unit Area = 0.224 mag


Since light travel time if about 0.7 Gyr, does it mean that this galaxy is 700 million light years distant, or in order to determine the distance we should look at age at redshift, which would indicate about 12,600 million light years away (this seems way too large though)?

The attached image shows the field of view in Simbad (right) and a crop from my image of this area - I did not want to edit your file :-)

EDIT: I think I got it. It seems that this galaxy is about 700 million light years away.

[Peter Ward]

A tidy image Ray. Nice one

[Shiraz (Ray)]

Originally Posted by Geoff45

Well done Ray. What was the reason behind the short exposures? Gettting better resolution? Tracking problems? Other?
Geoff

thanks Geoff. resolution - have found that short subs help a bit and they are possible with the ASI1600 due low read noise.

Originally Posted by atalas

Very nice Ray

thanks very much Louie

Originally Posted by Slawomir

Hi Ray

I looked this object up. It is a galaxy. Below are the coordinates and a bit of info about this galaxy:

Object name: LCRS B231626.6-422158
Co-ordinates: 23h19m11.5s -42d05m33s
Object type: Galaxy
Velocity: 16114 (km/s)
Red shift: 0.053750
Magnitude: 16.13


Cosmology-Corrected Quantities [Ho = 73.00 km/sec/Mpc, Ωmatter = 0.27, Ωvacuum = 0.73]
[Redshift 0.052940 as corrected to the Reference Frame defined by the 3K Microwave Background Radiation]
Luminosity Distance : 226 Mpc (m-M) = 36.77 mag
Angular-Size Distance : 204 Mpc (m-M) = 36.55 mag
Co-Moving Radial Distance : 215 Mpc (m-M) = 36.66 mag
Co-Moving Tangential Dist. : 215 Mpc (m-M) = 36.66 mag
Co-Moving Volume : 0.0417 Gpc^3
Light Travel-Time : 0.684 Gyr
Age at Redshift 0.052940 : 12.615 Gyr
Age of Universe : 13.299 Gyr
Scale (Cosmology Corrected): 990 pc/arcsec = 0.990 kpc/arcsec = 59.41 kpc/arcmin = 3.56 Mpc/degree
Surface Brightness Dimming : Flux Density per Unit Area = 0.81355; Magnitude per Unit Area = 0.224 mag


Since light travel time if about 0.7 Gyr, does it mean that this galaxy is 700 million light years distant, or in order to determine the distance we should look at age at redshift, which would indicate about 12,600 million light years away (this seems way too large though)?

The attached image shows the field of view in Simbad (right) and a crop from my image of this area - I did not want to edit your file :-)

EDIT: I think I got it. It seems that this galaxy is about 700 million light years away.

nice work Suavi. I think that the "age at redshift" is how old the universe was when the light started out - guess that the difference between that and 13.299Gy is how long the light has been travelling.

Originally Posted by Peter Ward

A tidy image Ray. Nice one

thanks a lot Peter - appreciated.

[marc4darkskies (Marcus)]

That's beautiful Ray! Great resolution and glorious colour!

[Shiraz (Ray)]

thanks Marcus! Cheers Ray

[willik (Willik)]

what a cracker top image and the detail good shot Ray
Martin

[Shiraz (Ray)]

Originally Posted by willik

what a cracker top image and the detail good shot Ray
Martin

Thanks Martin. Regards ray

[Paul Haese]

I thought I had commented on this image but it appears not.

Great detail and colour Ray. The image is quite sharp and it is as deep as my image with the RC and an STXL11002.

It's a good demonstration of a discussion here regarding sub lengths. My colour subs were 20 minutes long and the luminance were 30 minutes long. Yours were 1 and 2 minutes. I wonder how much your image would reveal if it were double the exposure.