Title:

EGB4 

Photograph By:

© Peter Goodhew 

Date Taken:

Monday, 30 December 2019 

Equipment Used:

APM TMB 152 F8 LZOS, 10 Micron GM2000HPS, QSI6120ws8 

Description:

EGB 4 (a nebula discovered by Ellis, Grayson, & Bond in 1984) is NOT a comet, despite it's comet-like appearance. It is an emission nebula surrounding a catacylismic binary star system called BZ Cam in the constellation of Camelopardis. 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. I can only find one previous image of EGB 4 online, a NASA APOD from 2000, so I believe this could be the first amateaur image and thefirst colour image. Yes it's incredibly faint! References: apod.nasa.gov/apod/ap001128.html THE ASTRONOMICAL JOURNAL, 115:286-295, 1998 January © 1998. The American Astronomical Society. aanda.org/articles/aa/full/2001