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By lux eterna
Last November I imaged the Bubble on a few occations with my Meade LX200-ACF and Nikon D7000 on SW HEQ5 Pro, guided with a standalone Nexguider. I managed some 10 hours under pretty good skies, plus 2 hours with H-alpha filter from my small town backyard. So almost 12 hours together (after rejecting every sub with just the slightest defect like non-circular or diffuse small stars).
Registering (aligning) was done in Registar, and stacking & processing in PS. I also used the Straton software that removes (most of) the stars, after initial stretching, then I put them back using the "lighten" blending mode.
C & C most welcome
IC 410 – The Tadpoles
IC 410 (‘The Tadpoles’) is a fascinating region of nebulosity in the Constellation of Auriga. This dusty star-forming region is part of a larger area of nebulosity that also contains IC405 (’The Flaming Star Nebula’) located around 13000 light years away. The gorgeous shapes within the nebula are sculpted from immense stellar winds from radiation developed by the large, hot young stars in the embedded open star cluster, NGC 1893.
The two immense, dense structures radiating away from the centre of the nebula give it its common name ‘The Tadpoles’. These are the remnants of vast pillars of dust and gas left over from the formation of the star cluster itself.
My main imaging focus recently has been to capture Ha data for B33 (‘The Horsehead Nebula’) but this object only rises above my local horizon after 22.00 so to fill the time while I wait for the Horse to arrive, I decided to capture IC 410 but the clear nights have – of course – coincided with the presence of the Moon ......... thank goodness for 3nm filters! I added my most recent data to that captured in October, 2017 to complete this phase of the image.
Mount: Mesu 200
Telescope: Sky-Watcher Esprit 150
Flattener: Sky-Watcher Esprit specific
Camera: QSI 683 WSG-8
Filter: Astrodon 3nm Ha
Subframes: 22 x 1800 sec Ha
Integration: 11 hours
Control: CCD Commander
Capture: MaxIM DL
Calibration and Stacking: PixInsight
Post-Processing: PhotoShop PS3
Recently in my effort to image Pluto, I used Stellarium to locate its position and compare the star fields with my image. I finally succeeded but my effort was made more difficult by a star that was visible in Stellarium near HIP 94372, but absent in my image Pluto Image post. On checking further I concluded that the error was in the NOMAD catalog used by Stellarium. If this is indeed the case does anyone know how this error can be reported and corrected?
The Great Barred Spiral Galaxy ( NGC 1365 ) in the constellation Fornax
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