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Found 3 results

  1. Tarantula Nebula ( NGC 2070 ) in Large Magellanic Cloud ( LMC ) by Mike O'Day. The Tarantula Nebula ( NGC 2070 ) is the largest and brightest emission nebula in the nearby irregular galaxy, the Large Magellanic Cloud ( LMC ). At a distance of 160,000 light years away from us, the Tarantula Nebula is so bright that it would cast shadows on the Earth if were as close to us as the Orion Nebula in our galaxy. New version ( April 9 ): ( please click / tap on image to see larger and sharper image ) ............ Older versions: And here it is re-processed to try to reduce the red background ( due to light pollution I think ) without impacting the colour of the stars too much ( please click / tap on image to see larger and sharper ) Details: Nebulae: NGC 2070 Tarantula Nebula NGC 2048 NGC 2060 NGC 2077 Open clusters: NGC 2042 NGC 2044 NGC 2050 NGC 2055 NGC 2091 NGC 2093 NGC 2100 Image centre ... (nova.astrometry.net) Field of view (arcmin): ... Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture ): 1410mm f4.7. Mount: Skywatcher AZ Eq6 GT. Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels). Filter: none. Exposures: 100 sub exposures ranging from 1s 100ISO to 240Sec 400ISO HDR processing of 5 sets of images Pixinsight & Photoshop 20 December 2016 / April 2017
  2. NGC 2014 and Dragon's Head nebula in the Magellanic Cloud ( LMC ) not far from the Tarantula Nebula by Mike O'Day ( 500px.com/MikeODay ). This image shows multiple bright nebula and star clusters in an area adjacent to the The Tarantula Nebula ( NGC 2070 ) in the nearby irregular galaxy, the Large Magellanic Cloud ( LMC ). The largest of these are the bright pink nebula in the mid-right part of the image ( NGC 2014 ) and the blue nebula in the lower middle ( NGC 2030 ). ..... Updated image - reprocessed to impove colour balance ( April 15th ) ( please click / tap on image to see it larger and sharper ) .... Original: ( click on image to see larger and clearer ( grrr... image compression in version above )) ---------- This is the first image captured as part of a new image capture and processing workflow I am trying out... Roger Clark ( http://www.clarkvision.com/articles/index.html ) has a number of articles addressing colour processing and the performance of modern DSLR sensors. The "take homes" for me have been: 1. With a modern sensor ( one with on-sensor dark current suppression technology ) one may not need to capture dark frames ( in order to remove the now non-significant pattern noise ). 2. "Correct" white balance processing should start by using "daylight" RBG channel multipliers ( to get the star colour 'right') and any histogram adjustment to improve white balance of darker parts of the image should involve aligning the left side of histogram curves ( ie. not the peaks ) So, the workflow to produce the image above involves calibraiton with Superbias & Master Flat but no dark frame subtraction (neither post nor in-camera). Roger Clark speaks of using a "bad pixel map" as the basis of reducing hot pixels. I have not figured out how to produce one yet. However, with a little bit of dithering during guiding ( and the very busy image ) the hot pixels that are in the image below are not too overwhelming. With regard to colour balance; I tried using the "daylight" factors reported by the camera but these resulted in an image and stars that were quite blue. This image was based on the factors reported by DXOMark for the Nikon D5300 ( R x 2.12, G x 1, B x 1.49 ( D50 standard )). This was better but I still felt the need for a final tweak in Photoshop ( colourBalance Highlights +15 Cyan/Red, -5 Magenta/Green ) to improve the colour in the stars and mid-tones. { DXOMark "white balance scales" for D5300 found at: https://www.dxomark.com/Cameras/Nikon/D5300---Measurements on the "color response" tab } --------- Details: Bright Nebulae: NGC 2014 ( upper right, pink) size 30 x 20 arcmin Mag +8 NGC 2020 size 2.0 arcmin ( small blue-green oval nebula ) NGC 2030 NGC 2032 ( Dragon's Head nebula - blue, central bottom of image ) NGC 2035 size 3.0 x 3.0 arcmin NGC 2040 size 3.0 x 3.0 arcmin Open clusters: NGC 2004 size 2.7 arcmin Mag +9.6 NGC 2011 size 1 arcmin Mag +10.6 NGC 2021 size 0.9 arcmin Mag +12.1 Annotated : Image centre RA 05h 33m 32.362s, Dec -67° 32' 18.145" (nova.astrometry.net) Orientation: up is west, right is South Field of view (arcmin): 58.8 x 39.2 Scale (full size image) 0.585 arcsec/pixel Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 120mm, f4 ). Corrector: ASA 2" Coma Corrector Quattro 1.175x. Effective Focal Length / Aperture : 1410mm f4.7 Mount: Skywatcher AZ Eq6 GT Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera: Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels) Format: 14bit NEF Noise reduction: off Filter: none HDR combination of seven sets of exposures (20 & 22 Feb 2017): 58 x 240 sec ISO 800 8 x 120 sec ISO 800 8 x 60 sec ISO 800 8 x 30 sec ISO 800 8 x 14 sec ISO 800 8 x 7 sec ISO 800 8 x 3 sec ISO 800 Pixinsight: 26 Feb 2017 Links: 500px.com/MikeODay photo.net/photos/MikeODay
  3. A new High Dynamic Range image of the Sculptor Galaxy ( NGC 253 ) captured over a number of nights in mid-September 2017 and processed with PixInsight using the DrizzleIntegration and PhotometricColorCalibration tools. The Silver Coin or Sculptor Galaxy ( NGC 253 ) in the Sculptor constellation. ( please click / tap on image to see larger and sharper ) On the 23rd of September 1783, sitting before her telescope in the field behind the house she shared with her brother William at Datchet, near Slough in the south of England, Miss Caroline Herschel "swept" the sky searching for new comets and never before seen star clusters and nebulae. On this occasion, way down in the sky, not far above the Southern horizon, in an area of the southern sky that Nicolas de Lacaille had called the “Apparatus Sculptoris” or “the sculptor’s studio", Miss Herschel saw and noted down a very bright and large nebula where one had never before been recorded. This event was later recognised by her brother, Sir William Herschel, as the discovery, by Caroline Herschel, of the nebula he listed in his catalogue as H V.1. In later years, her 'beloved nephew', Sir John Herschel, William's son, would record this 'nebula' as entry # 138 in his General Catalogue of Nebulae and Clusters of Stars ( eventually becoming the 253th entry in the New General Catalogue, NGC 253 ). Whilst relatively close to us compared to the billions of far more distant galaxies in the Universe, the great size of the “Sculptor Galaxy” and the huge distances involved are still hard to comprehend. To put this into some perspective, the light that is just now reaching one edge of the great disc left the opposite edge when the Earth was in the grip of last great Ice Age 70,000 years ago and the light we now see has been travelling towards us for over 11 million years. ........ More information on the discovery of the Sculptor Galaxy by Miss Caroline Herschel, as well as the later observations by both Sir William and Sir John Herschel, can be found in my Stargazerslounge blog, “The Sculptor Galaxy ( NGC 253 )” ......... This image was captured over a number of nights in the middle of September 2017 and processed on the 23rd; exactly 234 years from the day of its discovery by Caroline Herschel. With over 18 hours of total exposure, this HDR image attempts to capture the huge range of brightness levels; from the brightest stars and the core of the galaxy through to the numerous 'tiny' galaxies scattered throughout the image ( the total magnitude range is from around mag 8.8, for the brightest star, to 22+ for the faintest stars and galaxies visible in the image). Mike O'Day ...................... Capture Details: Telescope: Orion Optics CT12 Newtonian ( mirror 300mm, fl 1200mm, f4 ) Corrector: ASA 2" Coma Corrector Quattro 1.175x Effective Focal Length / Aperture : 1410mm f4.7 Mount: Skywatcher EQ8 Guiding: TSOAG9 Off-Axis-Guider, Starlight Xpress Lodestar X2, PHD2 Camera:Nikon D5300 (unmodified) (sensor 23.5 x 15.6mm, 6016x4016 3.9um pixels) Location: Blue Mountains, Australia Moderate light pollution ( pale green zone on darksitefinder.com map ).. Capture ( 16, 17, 19,20,22 Sept. 2017 ) 8 sets of sub-images with exposure duration for each set doubling ( 2s to 240s ) all at ISO800 273 x 240s + 10 each @ 2s to 120s total around 18hrs Processing Calibration: master bias, master flat and no darks. Drizzle Integration in 8 sets. HDR combination PhotometricColorCalibration Pixinsight & Photoshop 23 Sept. & 8 Oct 2017 Image Plate Solution ( this cropped image ) =============================================== Resolution ........ 1.324 arcsec/px Rotation .......... -180.00 deg ( South ^, East > ) Field of view ..... 57' 57.5" x 38' 40.1" Image center ...... RA: 00 47 32.809 Dec: -25 17 04.48 =============================================== .................... Designations and alternative names for the Sculptor Galaxy: CH10 ( Caroline Herschel # 10 ) H V.1 ( William Herschel, Class V ( very large Nebulae ) # 1 ) H 61, H 2345 ( John Herschel observations identifiers ) GC 138. ( John Herschel’s - A General Catalogue of Nebulae and Clusters of Stars # 138 ) NGC 253 ( John Herschel’s catalogue updated by Dreyer - The New General Catalogue of Nebulae and Clusters of Stars # 253 ) Caldwell 65 Leda 2789 ESO 479-29 Sculptor GalaxySilver Coin GalaxySilver Dollar Galaxy .................. Annotated image of the Sculptor Galaxy ( NGC 253 ) - showing the brighter stars ( from the Tycho-2 catalogue ) as well the galaxies recorded in the Principal Galaxies Catalogue ( PGC ). I have yet to complete identifying and annotating the very large number of ‘tiny’ galaxies in the image. ( please click / tap on image to see larger and sharper ) .........
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