PK164+31.1 (Jones-Emberson 1)

All Images Copyright Steve Cannistra

Please click here for a medium size (65%)
Please click here for a larger size (75%)
Please click here for the Ha version

Magnitude:  Approximately 14
FOV: A little less than 28' x 42' after cropping
RA (J2000): 07h 57m 52s
Dec (J2000): 53 degrees 25' 17"
Position Angle (Pinpoint):  plus 2 degrees

PK164+31.1 is a planetary nebula, which represents the end stage of stars between 1 and 8 solar masses (in contrast, stars much larger than our Sun typically undergo a supernova explosion).   Such stars live on the Main Sequence for about 10 billion years, during which they burn hydrogen to helium in their cores.  Eventually the core hydrogen becomes depleted and the star contracts, setting off burning of hydrogen to helium on its surface.  Thereafter the star gradually expands, becoming both cooler and more luminous (shifts to the upper right of the Hertzsprung-Russell diagram), transitioning into a red giant.  Eventually, enough pressure builds up in the core to start fusion of helium to carbon, and the star enters the Asymptotic Giant Branch (AGB) phase on the HR diagram.  The AGB phase is characterized by shedding of the star's outer layers into space, igniting surrounding elements such as hydrogen through excitation by the solar wind and heat, resulting in the characteristic gaseous shell of the planetary nebula.  The term "planetary" nebula is a misnomer and was coined by Herschel, based upon its superficial visual resemblance to his recently discovered planet, Uranus.  The PK catalogue was assembled by Czech astronomers Perek and Kohoutek in 1967, with the first number (164 in this case) representing galactic longitude (i.e., the plane of the Milky Way is used as the reference point), the second number (+31) representing galactic latitude, and the number after the decimal point (1) indicating that this object is the first to be catalogued in this region of space.

Photographic Details:
Date: November 23, 2008 (Ha); November 28 and 29, 2008 (RGB)
Scope:  Vixen VC200L at f6.1 (FL = 1235 mm) on the Takahashi NJP Mount
Autoguider:  SBIG ST-402 with 60mm guidescope, focal length 227mm
Camera:  Apogee U32 -25C
Astronomik Ha (6nm), R, G, B filters
Exposures:  Ha: 9 x 20' = 180' (unbinned); R: 6 x 10' = 60' (unbinned); G: 6 x 10' = 60' (unbinned); B: 8 x 15' = 120' (unbinned).  Total exposure 7 hours
Conditions:  Not ideal- intermittent clouds and generally poor seeing.  Typical winter weather in New England.
Post-processing:  Calibrated, aligned, and Sigma Clip combined in Maxim.  DDP in ImagesPlus (IP).  Deconvolution in Maxim using Bob Vanderbei's Fat Tail Deconvolution script (3 iterations).  Further processing in Photoshop CS (16 bit format).
Please note:  Graphics on this website may not be reproduced without author permission.

Back to Nebulae