Hemisphere:  Northern  ·  Contains:  NGC 1528  ·  NGC 4490
Visual deception: An open cluster  and a distant nebula..., 


            Antonio F. Sánchez
Visual deception: An open cluster  and a distant nebula...
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Visual deception: An open cluster and a distant nebula...

Technical card

Imaging telescopes or lenses: ASA N12 astrograph

Imaging cameras: FLI ML8300

Mounts: ASA DDM85 S-XL

Software: ASA Autoslew, Sequence...

Filters: Optec 50mm B  ·  Optec 50mm G  ·  Optec 50mm R  ·  Optec 50mm L

Accessory: FLI CFW-2-7 50mm round 7 position filter wheel

Dates:Oct. 1, 2013Oct. 2, 2013Oct. 3, 2013Oct. 4, 2013

Optec 50mm B: 19x600" -25C bin 1x1
Optec 50mm G: 16x600" -25C bin 1x1
Optec 50mm L: 59x600" -25C bin 1x1
Optec 50mm R: 16x600" -25C

Integration: 18.3 hours

Avg. Moon age: 27.51 days

Avg. Moon phase: 5.75%

Bortle Dark-Sky Scale: 2.00

Basic astrometry details

Astrometry.net job: 90807

RA center: 4h 13' 30"

DEC center: +51° 11' 16"

Pixel scale: 1.403 arcsec/pixel

Orientation: -179.942 degrees

Field radius: 0.584 degrees

Resolution: 2400x1796


SH2 - 209 is located in one of the outer arms , on the edge of our galaxy, about 16,000 light years ... overshadow by a dust cloud. As any other HII region,it is show when the ultraviolet radiation from surrounding stars ,ionize gas all around., thereby causing the brightness of the light spectrum visible.The surrounding dust is heated by radiation and this allows it to be seen also into infrared spectrum..These regions are characterized by being nest of new stars..

 This link can be seen and SH2 -209 SH2 -206 ( aka NGC 1491 ) portrayed by the WISE telescope in the infrared . SH2 -209 is located to the left of the image.


Discovered by William Herschel in 1790 , NGC 1528 is an open cluster (Archinal Brent and Steven Hynes catalog with about 165 stars) , with the brightest set in the order of magnitude 8.7 .. It stretches over about 13 year light into space..Ithas an estimated age of about 300-370 million years ago ( A modest age , compared with the cluster NGC 6791 in Lyra , which are attributed to between 7 and 8 billion years)
It is approximately at 1530 years light ... thus ,in the picture,althought both targets seeems to be into same plane ... SH2 -209 is about 14.5 thousand years more distant light.. A trifle :-)

The Russian astronomer A. V. Lotkin , has cataloged NGC1528 and NGC1545 ( another small cluster located less than a degree and a half , but not in this image field ) as a possible binary cluster probably captured by tidal.." Both clusters have similar galactic coordinates , ages , distances and mediam radial velocities If they are really a couple ...it could be the second double cluster in Perseus (besides the well-known " Double Cluster " NGC869 and NGC884 ) .

Credits of information :

Deep -Sky Companions : Hidden Treasures (Stephen James O'Meara ) .Cambridge University Press
NASA / JPL -Caltech / WISE Team



Antonio F. Sánchez
License: None (All rights reserved)

Sky plot

Sky plot


Visual deception: An open cluster  and a distant nebula..., 


            Antonio F. Sánchez