EGB 4
Astrobin Image Of The Day 9 January 2020
Amateur Astronomy Photo of the Day AAPOD2 25 January 2020
Published in Universo Magico 27 March 2020
EGB 4, despite its appearance, is not a comet.  It was originally thought to be a planetary nebula, but is now known to be an emission nebula surrounding a catacylismic binary star system called BZ Cam in the constellation Camelopardalis.

It has an unusual bow-shock structure as BZ Cam (with it's associated wind) moves through the interstellar medium, similar to the bow wave in front of a ship that is moving through water.

BZ Cam is believed to be a white dwarf star that is accreting mass from an accompanying main-sequence star of 0.3-0.4 solar masses.
It is around 2,500 light years away, and has a space velocity of 125 km/second.
Picture





TARGET
Nomenclature:  EGB 4, Ellis-Grayson-Bond 4
Right Ascension: 06:29:33.96
Declination: +71:04:36.3
Size: 4 arc min
Discovery: Ellis, Grayson, and Bond in 1984

EQUIPMENT USED
Twin APM TMB LZOS 152 refractors
10Micron GM2000 HPS mount
Twin QSI6120 CCD cameras
Astrodon filters
IMAGE CAPTURE
5nm Ha: 56x1800 bin 2x2
3nm OIII: 25x1800 bin 2x2
Luminance: 20x600 bin 1x1
Red: 15x300 bin 1x1
Green: 15x300 bin 1x1
Blue: 15x300 bin 1x1
Total integration: 47.6 hours
Pixel scale: 0.533 arcsec/pixel
Field radius: 0.368 degrees
Capture dates: 10-29 December 2019
Capture location:  Fregenal de la Sierra, Spain
IMAGE PROCESSING
Pre-processing: CCDStack2
Post-processing: Photoshop CS2
Ha image
OIII image