ASTRO: SH2-71

This is a very weird planetary in Cygnus. Rather large compared to most
planetaries and very oddly shaped. The bright star in the center is
the central star. It seems to be very bright for a central star.
That's because it isn't really the central star but it is in the center
of the nebula. The star that created the nebula is much fainter and is
seen only because the are a tight eclipsing binary system. The two
orbit each other every 12 hours! Some think the odd shape is due to the
second star in the core so close to the now dead star. Are they so
close that matter is being pulled to the white dwarf? Probably not but
it isn't totally impossible from what I've read. The light curve
apparently doesn't show the main sequence star being tidally disrupted
that I could find. I can't find any distance info on it.

Some faint red hydrogen fills the eastern (left side of the FOV. I
toned it down in the image to make the nebula stand out more. This is
just a LRGB image. With H-alpha and a wider FOV it might make an
interesting wide field shot. Something those with such a set-up might
want to try. I'm not kicking myself for toning it down. Makes the dark
lane that comes down along the left edge hard to see.

Visually I've seen it and the central star in my 10" but it isn't easy.
The 14" doesn't really help much. In fact the brighter central star
(I didn't see the orange one) is enough brighter it seemed to hinder
seeing the nebula. Odd for a 13.8 magnitude star! I didn't see the
effect in the 10" but there the star needed averted vision to see at all.

14" LX200R @ f/10, L=6x10' binned 2x2, RGB=2x10 binned 3x3, 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,

very nice image of this interesting nebula. My last try at it through a Halpha filter can be found at
http://www.slilge.de/Sharpless/sh2-71-29x5gut.jpg
Interesting to see that the central part of the nebula is blue (which of course is not uncommon for planetary nebulae, but I don't think I have seen this one in colour before).

Stefan

Originally Posted by Rick Johnson[_2_]

This is a very weird planetary in Cygnus. Rather large compared to most
planetaries and very oddly shaped. The bright star in the center is
the central star. It seems to be very bright for a central star.
That's because it isn't really the central star but it is in the center
of the nebula. The star that created the nebula is much fainter and is
seen only because the are a tight eclipsing binary system. The two
orbit each other every 12 hours! Some think the odd shape is due to the
second star in the core so close to the now dead star. Are they so
close that matter is being pulled to the white dwarf? Probably not but
it isn't totally impossible from what I've read. The light curve
apparently doesn't show the main sequence star being tidally disrupted
that I could find. I can't find any distance info on it.

Some faint red hydrogen fills the eastern (left side of the FOV. I
toned it down in the image to make the nebula stand out more. This is
just a LRGB image. With H-alpha and a wider FOV it might make an
interesting wide field shot. Something those with such a set-up might
want to try. I'm not kicking myself for toning it down. Makes the dark
lane that comes down along the left edge hard to see.

Visually I've seen it and the central star in my 10" but it isn't easy.
The 14" doesn't really help much. In fact the brighter central star
(I didn't see the orange one) is enough brighter it seemed to hinder
seeing the nebula. Odd for a 13.8 magnitude star! I didn't see the
effect in the 10" but there the star needed averted vision to see at all.

14" LX200R @ f/10, L=6x10' binned 2x2, RGB=2x10 binned 3x3, 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".

interesting and odd shape Rick


"Rick Johnson" wrote in message
ster.com...
This is a very weird planetary in Cygnus. Rather large compared to most
planetaries and very oddly shaped. The bright star in the center is
the central star. It seems to be very bright for a central star.
That's because it isn't really the central star but it is in the center
of the nebula. The star that created the nebula is much fainter and is
seen only because the are a tight eclipsing binary system. The two
orbit each other every 12 hours! Some think the odd shape is due to the
second star in the core so close to the now dead star. Are they so
close that matter is being pulled to the white dwarf? Probably not but
it isn't totally impossible from what I've read. The light curve
apparently doesn't show the main sequence star being tidally disrupted
that I could find. I can't find any distance info on it.

Some faint red hydrogen fills the eastern (left side of the FOV. I
toned it down in the image to make the nebula stand out more. This is
just a LRGB image. With H-alpha and a wider FOV it might make an
interesting wide field shot. Something those with such a set-up might
want to try. I'm not kicking myself for toning it down. Makes the dark
lane that comes down along the left edge hard to see.

Visually I've seen it and the central star in my 10" but it isn't easy.
The 14" doesn't really help much. In fact the brighter central star
(I didn't see the orange one) is enough brighter it seemed to hinder
seeing the nebula. Odd for a 13.8 magnitude star! I didn't see the
effect in the 10" but there the star needed averted vision to see at all.

14" LX200R @ f/10, L=6x10' binned 2x2, RGB=2x10 binned 3x3, 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".