British Astronomical Association
Supporting amateur astronomers since 1890

Secondary menu

Main menu

BAA Community

NGC869 & NGC884, the Double Cluster in Perseus

Image

Expand image

About this observation
Observer
John Hughes
Time of observation
09/10/2020 - 22:00
Object
NGC869 & NGC884
Observing location
North Essex, UK
Equipment
William Optics Z103 Refractor
ZWO ASI1600mm Pro Cooled camera
Chroma 1.25” filters LRGB
SkyWatcher EQ6-R Pro mount
Exposure
Gain 139, Offset 30

Having spent the last few months imaging nebulae and removing stars from images, it makes a nice change to concentrate on the stars.

One of my favourite star clusters is the Double Cluster in Perseus which is now rising nicely in the North East sky.

The Double Cluster itself is made up of two open clusters, NGC869 and NGC884 that are some 7,500 light years away. 

Analysis of the stars spectra show that the light is blue shifted meaning that both clusters are moving towards Earth. NGC884 has five prominent red supergiant stars though the star clusters themselves are young with an age of c12.8 million years. This suggests that both clusters formed from the same interstellar gas cloud.

 

This image was captured on 9 October 2020 from my garden. It is made up of the following data;

·       Red/Green/Blue - 18 subs @ 300 seconds for each filter.

·       Luminance - 30 subs @ 180 seconds.

·       Calibration frames - 50 separate darks, flats and flat darks.

Copyright of all images and other observations submitted to the BAA remains with the owner of the work. Reproduction of the work by third-parties is expressly forbidden without the consent of the copyright holder. For more information, please contact the webmaster.