Wouter's Astro-photography



NGC891 is a massive galaxy measuring about 110 000 light years in diamater and has a mass of about 150 billion suns. This splendid galaxy is seen almost perfectly from it's side which gives us a wonderful view on the dustlane.


This galaxy was discovered by Caroline herschel in 1784 and William herschel described it as "Considerably bright, much extended, above 15' long and 3' broad. A black division 3' or 4' long in the middle."


For small telescopes it's a great target provided that you have very dark skies. While the visual magnitude of 9.9 isn't that dim the surface brightnes is. This is due to the rather large apparent size of it . Though under dark skies it's not very hard to see even in a telescope as small as 4".


The image above was made at my home location in Belgium under heavily light polluted skies. (click the image for a larger view.)

Image data

Exposure: 72x300s

Filters: Baader UHC-S

Camera temperature: -15°C

Date: September 30th 2013

Location: Zele, Belgium




Camera: SBIG ST2000XM

Telescope: Skywatcher MN190

Mount: Software Bisque Paramount MX



Image aquisition: The Sky X

Preprocessing: Deep sky stacker

Fitsconversion: Fitsliberator

image processing: Adobe Photoshop CS5



Object data



Caldwell 23


Constellation: Andromeda



RA: 02h 22.6m

Dec: +42° 21'


Dimensions: 12.2' x 3.0'


Magnitude: 9.9


Surface brigtness: 13.7


Distance: 31 million lightyears


Discovered by Caroline Herschel in 1784


© Wouter D'hoye 2016 - Last update February 1st 2015