Astrophotography by Walt Davis

 Astrometry | Hi Res

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Object Information

Name: M51 (The Whirlpool Galaxy)
Type: Spiral Galaxy
Description:

Individually referred to as M51A (NGC 5194) and M51B (NGC 5195) are perhaps the most famous interacting galaxy pair, a black hole is thought to exist at the center of M51A.

Magnitude: 8.1
Size: 11.2 x 6.9 arcminutes

References:

M51
NGC 5195
Spiral Galaxy Google Images
Location

Hemisphere: Northern

Location:

Latitude 44.841N by Longitude -122.869W

Elevation: 90 Meters

Date:

February 18-21, 2009
Time  Zone: -8 (Pacific Standard Time)
Time: 10:00pm to 5:00am
Light Pollution: Class 4.5 on the Bortle scale (Rural/Suburban transition)
Equipment

Imager:

Nikon D90

OTA:

Nikkor 600mm F4 ED Telephoto Lens
Barlow: Nikkor TC-301 2x Teleconverter
Mount: Hypertuned Orion Atlas EQ-G
Guiding: Orion StarShoot Autoguider and Nikkor 300mm f2.8 ED Telephoto Lens
Imaging
Camera: Nikon D90 & StarShoot II DSCI
NR: ON (Mode 2)
Quality: RAW
Size: 4288 x 2848
ISO: variable
Exposure: variable
White Balance: Direct sunlight, 0, 0

Color Space:

adobeRGB
Exp Comp: 0EV
Metering: Spot
   

Filter:

Nikon 39mm Mounted Astronomik CLS
Scale: 0.38 arcseconds per pixel
FOV: 54.99 x 34.80 arcminutes
Cropped FOV: 41.31 x 34.65 arcminutes
   
Camera Control: ImagesPlus

Light Fames:

27 x (300sec @ ISO1600), 9 x (480sec @ ISO1600)

Darks:

auto darks via mode 2
Flats: none
   
Total Exposure: > 2 hours
Image Processing

Stacking:

DeepSkyStacker V 3.2.2 & RegiStar

Enhancement: PhotoShop CS3, Noiseware Professional, Astronomy Tools PS CS2 V1_5
Notes

Did not use an aperture mask to remove flaring of bright stars.

Copyright © 2008 Walt L. Davis All Rights Reserved