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Thursday, December 1, 2011

Simeis 147, a supernova remnant

Simeis 147, Sh2-240
In constellation Taurus

Image is in mapped colors, from the emission of ionized elements, R=Sulfur, G=Hydrogen and B=Oxygen. Note, the "noise" in background is not a noise but countless stars!

I shot H-alpha filtered lights for this image at many nights, after I shot lights for my Cygnus mosaic project.
After a midnight, Cygnus and its targets are too low in the horizon so I used rest of the night for this supernova remnant. Total exposure time for H-alpha, ~13h.

Simeis 147 (sharpless 240), is a very faint and very large supernova remnant in constellation Taurus at distance of ~3000 light years. It's constantly expanding at speed of 1000 km/second but due the size of it, we can't see any movement in it. This SN spans over 160 light years and the apparent scale in the sky is about three degrees (Moon has an apparent size of 30" = 0,5 degrees).  Explosion took place approximately 30.000 years ago  and left behind a  pulsar (Neutron star). The pulsar has recently identified.

I just did a small calculation, how long it takes to this supernova remnant to expand 1% large when the diameter is 160 light years and it expands at speed of 1000km/second.
Answer is ~480 years.
 (1% of diameter 160/100= 16, as kilometers ~151.372.800.000.00, = Y, km,
1000km/second is ~315.360.000.00, = Z, kilometers/year.
So, X x Z = Y and  X=Z/Y,    X = 480 with given values)

This is a difficult target to image and image above is my second try to capture it. An older version can be seen here. This older image was my second APOD from NASA.


Image in visual spectrum

Image in Natural color palette from the emission of ionized elements, 
R=Hydrogen + Sulfur, G=Oxygen and B=Oxygen + Hydrogen.
This palette is very close to a visual spectrum.

An animated image, with and without stars

This is an experimental image, the structure of filaments stands out nicely without stars.

Technical details:

Processing work flow:
Image acquisition, MaxiDL v5.07.
Stacked and calibrated in CCDStack2.
Deconvolution with a CCDStack2 Positive Constraint, 33 iterations, added at 50% weight
Levels, curves and color combine in PS CS3.

Optics, Canon EF 200mm camera lens at f1.8
Camera, QHY9
Guiding, Meade LX200 GPS 12" and a Lodestar guider
Image Scale, ~5 arcseconds/pixel
H-alpha 34x900s, Binned 1x1
H-alpha 14x1800s, Binned 1x1
Total exposure time for Hydrogen alpha is ~13h

O-III & S-II channels are from an older image, it can be seen here

1 comment:

Piotr Maliński said...

I'm trying to catch it with Atik 314L+ and a 100mm M42 lens + 7nm Baader H-alpha. After initial imaging night 2 weeks of fog and clouds forecasted :) I got a side of it, will have to rotate the camera next time. It's extremely faint, had to shoot 10 min exposures.

Would be cool if Stellarium or alike had images of all interesting rare nebulosity on the sky.