EGB 4 Astrobin Image Of The Day 9 January 2020 Amateur Astronomy Image of the Day AAPOD2 25 January 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.
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