ASTRO: Sedna

Nothing exciting here. Just something to do when waiting for the real
target to get high enough.

When discovered in November 2003 it was the most distant object
discovered in our solar system. Eris (which I imaged some time ago) is
currently the most distant dwarf planet but Sedna has an orbit that
takes it far beyond any known dwarf planet. Though for the next few
decades it is closer than Eris. But Sedna's albedo is much lower than
Eris so it is much dimmer. This made getting an image of it difficult.
I've marked its position with two short lines a bit below center but
even then it is hard to find in the image. During the 1.5 hours of this
exposure it moved only .75" of arc which is less than one pixel in my
image. The galaxy at the top of the image is UGC 2712 a SBd spiral
about 310 million light years away. I thought I'd moved the field down
enough to catch it but cut off its northern end. You can read more
about Sedna at this Wikipedia entry http://en.wikipedia.org/wiki/90377_Sedna
Their image of it isn't any better than mine. Sedna was supposed to be
at magnitude 21.3 when my image was taken but it was a good .6
magnitudes fainter according to my software and comparison to galaxies
of known magnitude in the image.

14" LX200R @ f/10, L=4x10' RGB=1x10', 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".

Good effort Rick. Looks like this is beyond my reach, I usually get to
something like mag 19.5 in a few hours.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
ster.com...
Nothing exciting here. Just something to do when waiting for the real
target to get high enough.

When discovered in November 2003 it was the most distant object
discovered in our solar system. Eris (which I imaged some time ago) is
currently the most distant dwarf planet but Sedna has an orbit that
takes it far beyond any known dwarf planet. Though for the next few
decades it is closer than Eris. But Sedna's albedo is much lower than
Eris so it is much dimmer. This made getting an image of it difficult.
I've marked its position with two short lines a bit below center but
even then it is hard to find in the image. During the 1.5 hours of this
exposure it moved only .75" of arc which is less than one pixel in my
image. The galaxy at the top of the image is UGC 2712 a SBd spiral
about 310 million light years away. I thought I'd moved the field down
enough to catch it but cut off its northern end. You can read more
about Sedna at this Wikipedia entry
http://en.wikipedia.org/wiki/90377_Sedna
Their image of it isn't any better than mine. Sedna was supposed to be
at magnitude 21.3 when my image was taken but it was a good .6
magnitudes fainter according to my software and comparison to galaxies
of known magnitude in the image.

14" LX200R @ f/10, L=4x10' RGB=1x10', 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".