The Rosette Nebula is a large H-II region located in the Monoceros region of our own Milky Way Galaxy. It has an apparent magnitude of 9.0 and lies about 5,200 light-years away. This nebula spans a swath of the sky about 130 light-years across. At the center of the nebula lies open cluster NGC 2244 (Caldwell 50), which was born from the Rosette's nebulosity around 4 million years ago, and was discovered by William Herschel in 1784. It is believed that the stellar winds from the cluster are blowing away nebulous matter which is creating the hole in the center of the nebula. Other designations for this nebula are NGC 2237,NGC 2238, NGC 2239, NGC 2246, Sharpless 275 (Sh2-275) and Caldwell 49. This image is in the synthetic RGB palette as detailed by Richard Crisp. Red = 100% H-alpha + 33% SII, Green = 100% OIII, Blue = 100% OIII + 33% H-alpha.
Telescope: Stellarvue Raptor SVR105 @ f/7 Accessories: Stellarvue SFF7-21 flattener; Dew control by Dew Buster; Alnitak Flat-Man; Aurora flat panel Mount: Takahashi EM-200 Temma2 Camera: QSI583wsg CCD @ -10.0C Guiding: Starlight Xpress Lodestar via PHD Filters: Astrodon 5nm Ha/OIII/SII Exposure: 12 x 20min. (Ha); 12 x 20min. (OIII); 12 x 20min. (SII) Acquisition: ImagesPlus Camera Control v5 Processing: Calibration, DDP in Images Plus v5; Registration in Registar Post-processing: ImagesPlus 5; Adobe Photoshop CS5; Noel Carboni's Actions Date(s): January 3, 4, 6, 7, 2013 SQM reading (begin - end): N1:19.10 - clouds; N2:19.07 - 19.06; N3:18.98 – 19.13; N4:19.03 – ?? Temperature (begin - end): N1:30.2ºF – 26.2ºF; N2:32.4ºF – 23.7ºF; N3:33.3ºF – 25.3ºF; N4:32.9ºF - ??ºF Location: Hendersonville, TN, USA