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The Great Barred Spiral Galaxy ( NGC 1365 ) in the constellation Fornax
edit: new version with new long exposure data ( 52 x 240sec ) and better dark subtraction / dithering to remove streaks in the noise and amp glow. This also allowed for a greater stretch revealing more faint data in the galaxy and small faint fuzzies in the image ..
The Great Barred Spiral Galaxy ( NGC 1365 ) in Fornax ( please click / tap to see larger )
and below I have added a 100% crop of new version:
NGC 1365 ( please click / tap on image to see larger )
The Great Barred Spiral Galaxy ( NGC 1365 ) in the Constellation Fornax
Below the equator, not seen from much of the Northern hemisphere, NGC 1365 passes very nearly directly overhead an observer situated near Cape Town, as Sir John Herschel was in November of 1837, or near Sydney, as I was, almost exactly 180 years later, when I photographed this “remarkable nebula” that is numbered 2552 in his book of observations from the Cape.
Not called a “nebula” now, of course, this striking object is one of the nearest and most studied examples of a barred spiral ( SB ) galaxy that also has an active galactic nuclei resulting in its designation as a Seyfert galaxy.
At around 60 M light years from Earth, NGC 1365 is still seen to occupy a relatively large area ( 12 by 6 arc minutes ) due to its great size; at some 200,000 light years or so across, NGC 1365 is nearly twice as wide as the Milky Way and considerably wider than both the Sculptor and Andromeda galaxies.
This High Dynamic Range ( HDR ) image is built up from multiple exposures ranging from 4 to 120 seconds with the aim of capturing the faint detail in the spiral arms of the galaxy whilst also retaining colour in the brightest star ( the orange-red 7th magnitude giant, HD 22425 ). Also, scattered throughout the image, and somewhat more difficult to see, are numerous and far more distant galaxies with apparent magnitudes of 16 to 18 or greater.
The Great Barred Spiral Galaxy
New General Catalogue - NGC 1365
General Catalogue - GC 731
John Herschel ( Cape of Good Hope ) # 2552 - Nov 28, 29 1837
Principal Galaxy Catlogue - PCG 13179
RA (2000.0) 3h 33m 37.2 s
DEC (2000.0) -36 deg 8' 36.5"
10th magnitude Seyfert-type galaxy in the Fornaux cluster of galaxies
200 Kly diameter
60 Mly distance
Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ).
Corrector: ASA 2" Coma Corrector Quattro 1.175x.
Effective Focal Length / Aperture : 1400mm f4.7
Mount: Skywatcher EQ
Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2
Camera: Nikon D7500 (unmodified) (sensor 23.5 x 15.7mm, 5568x3712 @ 4.196um pixels)
Blue Mountains, Australia
Moderate light pollution ( pale green zone on darksitefinder.com map )
Capture ( 22 Nov 2017 )
6 sets of sub-images with exposure duration for each set doubling ( 4s to 120s ) all at ISO400.
70 x 120s + 5 each @ 4s to 60s
total around 2.5hrs
Processing ( Pixinsight )
Calibration: master bias, master flat and no darks
Integration in 6 sets
Image - Plate Solution
Resolution ........ 1.328 arcsec/px
Rotation .......... -0.008 deg ( North is up )
Field of view ..... 58' 8.6" x 38' 47.5"
Image center ...... RA: 03 33 41.182 Dec: -36 07 46.71