The Omega Nebula, also known as the Swan Nebula, Checkmark Nebula, Lobster Nebula, and the Horseshoe Nebula (catalogued as Messier 17 or M17 and as NGC 6618) is an H II region in the constellation Sagittarius. It was discovered by Philippe Loys de Chéseaux in 1745. Charles Messier catalogued it in 1764. It is located in the rich starfields of the Sagittarius area of the Milky Way. The Omega Nebula is between 5,000 and 6,000 light-years from Earth and it spans some 15 light-years in diameter. The cloud of interstellar matter of which this nebula is a part is roughly 40 light-years in diameter and has a mass of 30,000 solar masses. The total mass of the Omega Nebula is an estimated 800 solar masses.
Tag Archives: M17
A Sagittarius Starscape

Image Credit & Copyright: Terry Hancock (Down Under Observatory)
This rich starscape spans nearly 7 degrees on the sky, toward the Sagittarius spiral arm and the center of our Milky Way galaxy. A telescopic mosaic, it features well-known bright nebulae and star clusterscataloged by 18th century cosmic tourist Charles Messier. Still popular stops for skygazers M16, the Eagle (far right), and M17, the Swan (near center) nebulae are the brightest star-forming emission regions. With wingspans of 100 light-years or so, they shine with the telltale reddish glow of hydrogen atoms from over 5,000 light-years away. Colorful open star cluster M25 near the upper left edge of the scene is closer, a mere 2,000 light-years distant and about 20 light-years across. M24, also known as the Sagittarius Star Cloud, crowds in just left of center along the bottom of the frame, fainter and more distant Milky Way stars seen through a narrow window in obscuring fields of interstellar dust.
APOD NASA 05-Sep-14
Omega Nebula
The Omega Nebula, also known as the Swan Nebula, Checkmark Nebula, Lobster Nebula, and the Horseshoe Nebula (catalogued as Messier 17 or M17 and as NGC 6618) is an H II region in the constellation Sagittarius.
The Omega Nebula is between 5,000 and 6,000 light-years from Earth and it spans some 15 light-years in diameter. The cloud ofinterstellar matter of which this nebula is a part is roughly 40 light-years in diameter and has a mass of 30,000 solar masses. The total mass of the Omega Nebula is an estimated 800 solar masses.
Imaging telescopes or lenses: Officina Stellare Veloce RH200
Imaging cameras: QSI 683WSG
Mounts: Skywatcher N-EQ6 pro
Guiding telescopes or lenses: Officina Stellare Veloce RH200
Guiding cameras: Starlight Xpress Lodestar
Software: PixInsight, Maxim DL
Filters: Astrodon Ha 3nm Tru-Balance, Astrodon OIII
Accessories: Finger Lake Instruments Atlas Focuser
Dates: Aug. 16, 2014, Aug. 17, 2014
Frames:
Astrodon Ha 3nm Tru-Balance: 14×600″
Astrodon OIII: 6×600″
Integration: 3.3 hours
Author: Davide Manca
AstroPhotography of the day by SPONLI 04 Sep 2014
M17 or Omega Nebula
The Omega Nebula, also known as the Swan Nebula, Checkmark Nebula, Lobster Nebula, and the Horseshoe Nebula (catalogued as Messier 17 or M17 and as NGC 6618) is an H II region in the constellation Sagittarius. It was discovered by Philippe Loys de Chéseaux in 1745. Charles Messier catalogued it in 1764. It is located in the rich starfields of the Sagittarius area of the Milky Way.
The Omega Nebula is between 5,000 and 6,000 light-years from Earth and it spans some 15 light-years in diameter. The cloud ofinterstellar matter of which this nebula is a part is roughly 40 light-years in diameter and has a mass of 30,000 solar masses. The total mass of the Omega Nebula is an estimated 800 solar masses. It is considered one of the brightest and most massive star-forming regions of our galaxy. Its local geometry is similar to the Orion Nebula except that it is viewed edge-on rather than face-on.
Imaging telescopes or lenses: William Optics FLT98
Imaging cameras: Atik 383L+
Mounts: Skywatcher EQ8
Guiding telescopes or lenses: William Optics FLT98
Guiding cameras: Starlight Xpress Loadstar
Focal reducers: Riccardi Reducer 0,75x
Software: Fitswork 4.44, Adobe Photoshop CS3 CS3
Filters: Baader S2, Baader Planetarium Ha 7nm 2″, Baader O III 8.5nm O3
Accessories: Starlight Xpress 5×2″ Filter Wheel
Dates: June 8, 2014
Frames: 25×900″
Integration: 6.2 hours
Author: Alexander Sielski
AstroPhotography of the day by SPONLI 4 Aug 2014
Omega Nebula in Sagittarius
The Omega Nebula, also known as the Swan Nebula, Checkmark Nebula, Lobster Nebula, and the Horseshoe Nebula (catalogued as Messier 17 or M17 and as NGC 6618) is an H II region in the constellation Sagittarius. It was discovered by Philippe Loys de Chéseaux in 1745. Charles Messier catalogued it in 1764. It is located in the rich starfields of the Sagittarius area of the Milky Way.
The Omega Nebula is between 5,000 and 6,000 light-years from Earth and it spans some 15 light-years in diameter. The cloud ofinterstellar matter of which this nebula is a part is roughly 40 light-years in diameter and has a mass of 30,000 solar masses. The total mass of the Omega Nebula is an estimated 800 solar masses.
Imaging telescopes or lenses: GSO Newton 12″ f/4
Imaging cameras: ATIK 11000m
Mounts: Skywatcher EQ8
Guiding telescopes or lenses: Orion 50 mm mini guider
Guiding cameras: Orion Star Shoot Planetary Imager & Autoguider
Focal reducers: ASA Wynne 3″ Corrector 0.95x
Software: photoshop, Startools 1.3.5, CCDStack, Maxim DL
Filters: Orion 2” LRGB filter set, Baader Ha 2″
Dates: June 6, 2014
Frames:
Orion 2” LRGB filter set: 9×300″ -15C bin 2×2
Baader Ha 2″: 4×600″ -15C bin 1×1
Integration: 1.4 hours
Author: Paul Storey
AstroPhotography of the day by SPONLI 18 July 2014
Star Factory Messier 17

Image Credit & Copyright: Subaru Telescope (NAOJ), Hubble Space Telescope;
Processing: Robert Gendler & Roberto Colombari
What’s happening at the center of this nebula? Sculpted by stellar winds and radiation, the star factory known as Messier 17 lies some 5,500 light-years away in the nebula-rich constellation Sagittarius. At that distance, this degree wide field of view spans almost 100 light-years. The sharp, composite, color image utilizing data from space and ground based telescopes, follows faint details of the region’s gas and dust clouds against a backdrop of central Milky Way stars. Stellar winds and energetic light from hot, massive stars formed from M17’s stock of cosmic gas and dust have slowly carved away at the remaining interstellar material producing the cavernous appearance and undulating shapes. M17 is also known as the Omega Nebula or the Swan Nebula.
NASA APOD 27-May-14
The Omega Nebula
The Omega Nebula is between 5,000 and 6,000 light-years from Earth and it spans some 15 light-years in diameter. The cloud of interstellar matterof which this nebula is a part is roughly 40 light-years in diameter and has a mass of 30,000 solar masses. The total mass of the Omega Nebula is an estimated 800 solar masses.
It is considered one of the brightest and most massive star-forming regions of our galaxy. Its local geometry is similar to the Orion Nebula except that it is viewed edge-on rather than face-on.
An open cluster of 35 stars lies embedded in the nebulosity and causes the gases of the nebula to shine due to radiation from these hot, young stars; however the actual number of stars in the nebula is much higher – up to 800, 100 of spectral type earlier than B9, and 9 of spectral type O, plus >1000 stars in formation on its outer regions. It’s also one of the youngest clusters known, with an age of just 1 million years.
The luminous blue variable HD 168607, located in the south-east part of the Omega nebula, is generally assumed to be associated with it; its close neighbor, the blue hypergiant HD 168625, may be too. The Swan portion of M17, the Omega Nebula in the Sagittarius nebulosity is said to resemble a barber’s pole.
Imaging telescopes or lenses: Takahashi TOA 150
Imaging cameras: Canon EOS 5D Mark II MOD
Mounts: Takahashi EM-400 Temma2
Guiding telescopes or lenses: Vixen FL70S
Guiding cameras: Fishcamp Starfish
Focal reducers: Takahashi TOA 67 Flattener
Software: DeepSkyStacker, Adobe Photoshop CS3
Filters: UV/IR-cut
Dates: July 31, 2011
Locations: Mt. Ho-Huan (Taiwan)
Frames: UV/IR-cut: 18×300″ ISO1600
Integration: 1.5 hours
Autor: Wei-Hao Wang
02 March 2014
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