ASTRO: NGC 7788 and 7790

NGC 7788 and 7790 right to left. These two small open clusters are
located in Cassiopeia and are bout 7,700 and 9,600 light-years away
respectively. The distance to NGC 7790 is likely more accurate as it
contains three Cepheid variable stars which help pin down its 9,600
light-year distance. NGC 7788 is a rather new cluster, probably only
about 40 million years old. NGC 7790 is thought to be a bit older at 56
million years old. I've seen speculation the two clusters are related
since the distance to NGC 7788 is rather uncertain. But the age
difference would seem to rule this out.

The three Cepheids in NGC 7790 are rather easy to find. They are the
TWO brightest orange stars at the Northwest end of the cluster. Notice
the brighter of the two is a bit elongated. Seems it is a binary made
up of two Cepheids and is known as the variable CE CAS the other Cepheid
to its southeast is CF Cass. The bright blue star below the southeast
end is the eclipsing binary QX CAS and was discovered in 1956 when the
Cepheids were being studied. It varies from 10.19 to 10.7 magnitude.

My system isn't well suited for most open clusters. These two fit my
system rather well. I haven't stretched the image nearly as far as I
usually do for faint galaxies so it doesn't begin to go as deep as I
normally go. This seemed to make for an image that didn't look as flat
as my clusters do with more stretching as it packs too much range into
the limited range of a computer monitor. I thought this one came out
better than most of my attempts at open clusters. Since there wasn't
much to see at higher resolution I down converted the image to 1.5" per
pixel from my normal 1" per pixel.

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

Rick,

those two look really nice. I have added my version of this field from October for comparison (Skywatcher ED 120, Atik 383, 9x2 Minutes each for RGB).

Stefan

Originally Posted by Rick Johnson[_2_]

NGC 7788 and 7790 right to left. These two small open clusters are
located in Cassiopeia and are bout 7,700 and 9,600 light-years away
respectively. The distance to NGC 7790 is likely more accurate as it
contains three Cepheid variable stars which help pin down its 9,600
light-year distance. NGC 7788 is a rather new cluster, probably only
about 40 million years old. NGC 7790 is thought to be a bit older at 56
million years old. I've seen speculation the two clusters are related
since the distance to NGC 7788 is rather uncertain. But the age
difference would seem to rule this out.

The three Cepheids in NGC 7790 are rather easy to find. They are the
TWO brightest orange stars at the Northwest end of the cluster. Notice
the brighter of the two is a bit elongated. Seems it is a binary made
up of two Cepheids and is known as the variable CE CAS the other Cepheid
to its southeast is CF Cass. The bright blue star below the southeast
end is the eclipsing binary QX CAS and was discovered in 1956 when the
Cepheids were being studied. It varies from 10.19 to 10.7 magnitude.

My system isn't well suited for most open clusters. These two fit my
system rather well. I haven't stretched the image nearly as far as I
usually do for faint galaxies so it doesn't begin to go as deep as I
normally go. This seemed to make for an image that didn't look as flat
as my clusters do with more stretching as it packs too much range into
the limited range of a computer monitor. I thought this one came out
better than most of my attempts at open clusters. Since there wasn't
much to see at higher resolution I down converted the image to 1.5" per
pixel from my normal 1" per pixel.

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Rick
--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".