Sunday, March 24, 2013
Jones-Emberson 1, a Palnetary Nebula
I have shot some new h-alpha data for this extremely dim planetary nebula. Total exposure time is now around 20h for the light emitted by an ionized Hydrogen alone. Colors are shot simultaneously with H-a by using the Tokina AT-X 300mm f2.8 camera optics, UHC-sfilter and a cooled single shot color astrocamera, QHY8. Exposure time for the color information is around 8h. Total exposure time used is ~23h.
NOTE!
An unknown outer shell structure might be visible in my color data! It can be an artifact though and much more exposures are needed to show it well enough to be sure. Explanation at the end of this post.
Jones-Emberson 1
Ra 07h 57m 51.628s Dec +53° 25′ 16.96
PK 164+31.1 a planetary nebula in Lynx
A cropped full size image, this is a large object as a planetary nebua.
Image is in visual spectrum and dominated by the red light emitted by ionized Hydrogen, H-alpha. Blueish hues are from ionized Oxygen, O-III. Colors are shot simultaneously with H-a emission by using QHY8 color camera, Tokina AT-X 300mm f2.8 camera lens and Baader UHCs-filter.
NOTE. An updated image, 5h of O-III data added 25.03.
NOTE. An updated image, 5h of O-III data added 25.03.
A wider field
NOTE. An updated image, 5h of O-III data added 25.03.
INFO
There are many background galaxies in this image but they are not showing very well, due to narrowband imaging method. Galaxies and stars are broadband targets and they dim down much, when narrowband filters are used. I'll like to be able to shoot this from a dark location with a LRGB-method.
largish and very dim, planetary nebula.PK 164+31.1, sometimes known as a "Jones-Emberson 1" has an angular diameter of 6', 67" x 6', 67" and it locates in constellation Lynx. Distance from my home town Oulu, Finland, is about 1600 light years.
The tiny Blue central star is a white dwarf, the intense ultraviolet light emitted by this star makes elements in a ring glow. Ionized Hydrogen emits red light and the ionized Oxygen blue one.
Why the name "PK 164+31.1"?
PK comes from the names of Czechoslovakian astronomers Perek and Kouhutec. 1967 they created an extensive catalog of all of the known planetary nebulae in 1964. The number indicates the position in the sky. The alternative name "Jones-Emberson 1" is after its discoveries.
Jones-Emberson 1, H-alpha emission alone
Image shows this planetary nebula in light emitted by an ionized Hydrogen, H-alpha. In color image, there is also light from an ionized Oxygen, O-III. (H-a emits red light and O-III green/blue light.)
Technical details
Processing work flow:
Image acquisition, MaxiDL v5.07.
Stacked and calibrated in CCDStack2.
Levels, curves and color combine in PS CS3.
Optics, Meade LX200 GPS 12" @ f5
Camera, QHY9
Guiding, SXV-AO, an active optics unit, and Lodestar guide camera 5Hz
Image Scale, ~0,8 arc-seconds/pixel
Exposures
H-alpha 21x1200s, binned 1x1 = 8h (A new set from spring 2013)
(Older sets from Spring 2010)
H-alpha 32x1200s, binned 2x2 and 7x1200s, binned 3x3 = 13h
O-III 2x600s, binned 4x4 and 1x1200s, binned 4x4 = 1h
S-II 3x600s, binned 4x4 and 1x1200s, binned 4x4 = 1h 20min.
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Color exposures with QHY8 single shot color camera, spring 2013
48x600s exposures with UHC-sfilter = 8h
48x600s exposures with UHC-sfilter = 8h
A single unprocessed 1200 second frame of H-a emission
A single 20 min. frame, just calibrated and nonlineary stretched to visible.
Imaged with the QHY9 camera, Baader 7nm H-alpha filter and Meade LX200 12" telescope.
Color data
This is a image used for colors only, it doesn't need to be high resolution, nor pretty, since there are very litle details in other than H-a channel.
A UHCs filtered data from Tokina AT-x 300mm f2.8 camera lens, total 8h.
Possible finding, an outer shell?
After removing all the stars from the color image above, I was able to stretch the individual color channels to an extreme, without blowing the stars. It is possible, that there is an unknown outer shell in this nebula!
It's possible, that this is just an artifact and much more exposures are needed to show it well enough to be sure. This season starts to be over up here 65N but I'll continue to study this at next spring season, 2014.
A very strongly stretched starless color image of Jones-Emberson 1, 8h exposure, shows a hint of an outer shell structure at mostly Right side at the image above. Outer shell seems to be a pure O-III emission and that's kind of typical to a many planetray nebulae. But as mentioned, this is speculation until I have more data.
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