ASTRO: vdB 24 and 4 YSOs

VdB 24 is an interesting reflection nebula in Perseus illuminated by the
star XY Persei, a 9th magnitude variable star that can dim down to
magnitude 11. It is also a double star, an A2II and a B6e separated by
about 1.3" of arc. Parallax puts the star at about 390 light-years. I
would assume that is also the distance to vdB 24. Though I've found
references to it being much further, 1,140 light-years.

The Holoea, from sometime back is a YSO (Young stellar Object) which is
a protostar just turning on. Holoea was accompanied by a stream of gas
it was somehow creating. The papers I looked at on it considered YSOs
very rare. Yet there are 4 of them in this image! Two are easy to
spot, the other two are IR objects though there's a hint of something
around the eastern one of these two if you blow up my annotated image.
I have labeled all 4 with a line drawn to the position for the YSO. The
northernmost looks like a fairly bright star. It's far brighter in far
IR frequencies. Below it is a rather white star that marks the position
of the other visible YSO. Neither show any sign of a gas stream.
There's no obvious object at the positions of the other two though they
shine rather brightly in far IR light. The easternmost one shows a
smudge on the POSS 2 IR film image that is much brighter than the smudge
on my visible light image (I block IR from reaching the camera). I
thought it just noise in my image but it is exactly the same spot as the
smudge in the POSS 2 IR image. I see nothing in the POSS 2 IR image at
the position of the 4th YSO however.

The image was taken over 3 very poor nights. Even though this is made
up of 110 minutes of luminance compared to my normal 40 it doesn't begin
to go as deep as I normally go in 40 minutes. I marked it for a redo
but that hasn't happened so I processed this.

In praise of the Paramount I'll just mention that ALL 23 frames were
stacked without alignment even though taken over 3 days. The ability to
return several nights later to exactly the same point without effort
still amazes me, even after 6 years. Though in this case if I'd known
I'd be taking so many frames I'd have dithered and thus had to align.

14" LX200R @ f/10, L=11x10' RGB=4x10', STL-11000XM, Paramount ME

Rick
--
Prefix is correct. Domain is arvig dot net

Rick,

you seem to go for the tough nebulae if you can't find tough galaxies ;-)
In spite of the poor conditions you managed to get a deep and detailed view.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
. com...
VdB 24 is an interesting reflection nebula in Perseus illuminated by the
star XY Persei, a 9th magnitude variable star that can dim down to
magnitude 11. It is also a double star, an A2II and a B6e separated by
about 1.3" of arc. Parallax puts the star at about 390 light-years. I
would assume that is also the distance to vdB 24. Though I've found
references to it being much further, 1,140 light-years.

The Holoea, from sometime back is a YSO (Young stellar Object) which is
a protostar just turning on. Holoea was accompanied by a stream of gas
it was somehow creating. The papers I looked at on it considered YSOs
very rare. Yet there are 4 of them in this image! Two are easy to
spot, the other two are IR objects though there's a hint of something
around the eastern one of these two if you blow up my annotated image.
I have labeled all 4 with a line drawn to the position for the YSO. The
northernmost looks like a fairly bright star. It's far brighter in far
IR frequencies. Below it is a rather white star that marks the position
of the other visible YSO. Neither show any sign of a gas stream.
There's no obvious object at the positions of the other two though they
shine rather brightly in far IR light. The easternmost one shows a
smudge on the POSS 2 IR film image that is much brighter than the smudge
on my visible light image (I block IR from reaching the camera). I
thought it just noise in my image but it is exactly the same spot as the
smudge in the POSS 2 IR image. I see nothing in the POSS 2 IR image at
the position of the 4th YSO however.

The image was taken over 3 very poor nights. Even though this is made
up of 110 minutes of luminance compared to my normal 40 it doesn't begin
to go as deep as I normally go in 40 minutes. I marked it for a redo
but that hasn't happened so I processed this.

In praise of the Paramount I'll just mention that ALL 23 frames were
stacked without alignment even though taken over 3 days. The ability to
return several nights later to exactly the same point without effort
still amazes me, even after 6 years. Though in this case if I'd known
I'd be taking so many frames I'd have dithered and thus had to align.

14" LX200R @ f/10, L=11x10' RGB=4x10', STL-11000XM, Paramount ME

Rick
--
Prefix is correct. Domain is arvig dot net