Gyulbudaghian's (variable) Nebula revisted for the 3rd time

Gyulbudaghian's Nebula is a reflection nebula around PV Cephi which is in quite a large dust cloud. Like other such nebulae in dust around newly forming stars it is a variable nebula. Hubble's Variable Nebula is the most famous but there are others such as NGC 1555, aka Hind's Variable Nebula, lit by T Tauri. Gyulbudaghian's Nebula is yet another example. Checking the POSS 2 plates there is a huge change between the time the red and blue images were taken.

I first imaged this one on September 24, 2011 under very good conditions. After seeing some low resolution images taken in the fall of 2013 that appeared to show a change I put it back on the to-do list. Seeing and transparency never cooperated. About the time it was getting too far west I had a go at it anyway on December 24, 2013. Poorer seeing and transparency conditions make a comparison impossible other than to say it has obviously changed greatly over the 27 months.

I then put it on the to-do list for a retake in 2014. Weather sort of cooperated on September 15 for the luminance data. I lost all color data to clouds. I tried again on the 16th. Seeing was much worse but transparency better. At least at the start. The red data was good just fuzzy from seeing. Green was fair and blue had very poor transparency. This may be why the red portions of the nebula it lies in is much redder this year. I tried again until the moon made that impossible. I finally gave up and went with this data since it shows the nebula has obviously changed and later attempts would likely be of a yet different nebula with different colors so I couldn't use the color data anyway.

To the upper left of the nebula is a small highly elongated nebulous patch. The lower section is the Herbig Haro object #415. I found no separate designation for the upper longer section. It too may be the HH object but the coordinates for it at SIMBAD point to the lower section. The dark nebula in the lower right is LDN 1155C, part of the larger LDN 1155 outside of my image. What few galaxies are in the image and listed at NED are listed only by coordinates so I didn't make an annotated image. One is available at my 2013 post http://www.spacebanter.com/attachmen...5&d=1402648490 .
My full image from 2011 can be seen at: http://www.spacebanter.com/attachmen...9&d=1347392450 . My 2011 image was with my old filters that tended to put a blue cast I'd not learned to remove. I should reprocess it.

I've attached a crop of the nebula as seen all three years. For 2011 I used my overly blue sensitive filters but the same new ones for the last two years. Still due to transparency issues there's a color shift I'm not happy with. The comparison images are at about 0.8" per pixel though due to temperature differences between the nights there is some difference in image scale evident.

14" LX200R @ f/10, L=8x10' RGB=2x10', STL-11000XM, Paramount ME

Great series Rick, you captured a lot of detail.
This one and Hind's have been on my list for a long time but always managed
to escape.

Stefan

"WA0CKY" schrieb im Newsbeitrag ...


Gyulbudaghian's Nebula is a reflection nebula around PV Cephi which is
in quite a large dust cloud. Like other such nebulae in dust around
newly forming stars it is a variable nebula. Hubble's Variable Nebula
is the most famous but there are others such as NGC 1555, aka Hind's
Variable Nebula, lit by T Tauri. Gyulbudaghian's Nebula is yet another
example. Checking the POSS 2 plates there is a huge change between the
time the red and blue images were taken.

I first imaged this one on September 24, 2011 under very good
conditions. After seeing some low resolution images taken in the fall
of 2013 that appeared to show a change I put it back on the to-do list.
Seeing and transparency never cooperated. About the time it was getting
too far west I had a go at it anyway on December 24, 2013. Poorer
seeing and transparency conditions make a comparison impossible other
than to say it has obviously changed greatly over the 27 months.

I then put it on the to-do list for a retake in 2014. Weather sort of
cooperated on September 15 for the luminance data. I lost all color
data to clouds. I tried again on the 16th. Seeing was much worse but
transparency better. At least at the start. The red data was good just
fuzzy from seeing. Green was fair and blue had very poor transparency.
This may be why the red portions of the nebula it lies in is much redder
this year. I tried again until the moon made that impossible. I
finally gave up and went with this data since it shows the nebula has
obviously changed and later attempts would likely be of a yet different
nebula with different colors so I couldn't use the color data anyway.

To the upper left of the nebula is a small highly elongated nebulous
patch. The lower section is the Herbig Haro object #415. I found no
separate designation for the upper longer section. It too may be the HH
object but the coordinates for it at SIMBAD point to the lower section.
The dark nebula in the lower right is LDN 1155C, part of the larger LDN
1155 outside of my image. What few galaxies are in the image and listed
at NED are listed only by coordinates so I didn't make an annotated
image. One is available at my 2013 post http://tinyurl.com/mwaqsq6 .
My full image from 2011 can be seen at: http://tinyurl.com/oeb957g . My
2011 image was with my old filters that tended to put a blue cast I'd
not learned to remove. I should reprocess it.

I've attached a crop of the nebula as seen all three years. For 2011 I
used my overly blue sensitive filters but the same new ones for the last
two years. Still due to transparency issues there's a color shift I'm
not happy with. The comparison images are at about 0.8" per pixel
though due to temperature differences between the nights there is some
difference in image scale evident.

14" LX200R @ f/10, L=8x10' RGB=2x10', STL-11000XM, Paramount ME


--
WA0CKY