240118 - M82 "Cigar" galaxy
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ASTRO:
type=starburst galaxy const=Ursa Major mag=8.4 dist=12 M ly size=37 k ly IMAGE: location=EB Driveway BrtlCls=4 moon=25% WxCr exposure=CMOS OSC: 54x300s (4.5h) palette=(R+Ha)GB EQUIPMENT: camera=ZWO ASI2600MC-Pro optics=ES102 w24mmEP 1.7x prjctn, FL(eff)=1238mm, f/12.1 filters=RGB: Optolong L-Pro LPS; Ha: Radian Triad Ultra Quad NB mount=Celestron AVX guiding=Orion 60x240mm, ZWO ASi224MC SOFTWARE: acquisition=Stellarium, APT, PHD2 processing=PixInsight, RCAstro, PhotoshopCC, APF-R, Lumenzia, LrC |
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The Cigar Galaxy, also known as Messier 82 (or M82) and NGC 3034 is a starburst galaxy located appx 12 million light-years away in the constellation Ursa Major. A member of the M81 Group, M82 is a highly studied object by the scientific astronomical community. It is a remarkable object for its webs of shredded clouds and flame-like plumes of glowing hydrogen gas blasting out from its central regions where young stars are being born at a rate 10 times faster than they are inside in our home Milky Way galaxy. M82 averages about five times more luminous than the Milky Way, and its central core is appx 100x more luminous. The starburst activity (seen as the red tendrils emanating outward into the surrounding space on either side of the galaxy center) is thought to have been triggered by interaction with neighboring galaxy M81. As the closest starburst galaxy to Earth, M82 is a prototypical example of this galaxy type. Super Nova 2014J, a type 1a supernova, was discovered inside M82 on January 21, 2014. Also in 2014, scientists discovered the brightest pulsar yet known inside the galaxy, designated M82 X-2.
M82 was believed to be an irregular galaxy, being void of many of the more common features observed in many other galaxies. In 2005, however, two symmetric spiral arms were discovered in images captured in the near-infrared (NIR) spectrum. Even though the arms were detected in NIR images, they are 'bluer' than the main disk. The arms had been missed due to M82's high surface brightness, the nearly edge-on view of the galaxy (~80°), and by a complex network of dusty filaments that obscured the arms from view. These arms can be seen in optical images using special photometric techniques which show they emanate from the ends of a central bar. They can be followed for a length of appx 3 disc scales. Also, assuming that the northern part of M82 is nearer to us, the observed sense of rotation implies the arms are 'trailing' in orientation to the motion of the center of the galaxy.
In 2005, the Hubble Space Telescope revealed 197 young massive star clusters inside the starburst core. The average mass of these clusters is around 200,000 solar masses, which gives rise to the theory that the starburst core is a very energetic and highly-dense environment. M82's unique bipolar outflow (or 'superwind') appears to be concentrated in two (2) of the clusters, and is fueled by energy released from supernovae within the clusters, occurring at a rate of about one every ten years.
M82 was believed to be an irregular galaxy, being void of many of the more common features observed in many other galaxies. In 2005, however, two symmetric spiral arms were discovered in images captured in the near-infrared (NIR) spectrum. Even though the arms were detected in NIR images, they are 'bluer' than the main disk. The arms had been missed due to M82's high surface brightness, the nearly edge-on view of the galaxy (~80°), and by a complex network of dusty filaments that obscured the arms from view. These arms can be seen in optical images using special photometric techniques which show they emanate from the ends of a central bar. They can be followed for a length of appx 3 disc scales. Also, assuming that the northern part of M82 is nearer to us, the observed sense of rotation implies the arms are 'trailing' in orientation to the motion of the center of the galaxy.
In 2005, the Hubble Space Telescope revealed 197 young massive star clusters inside the starburst core. The average mass of these clusters is around 200,000 solar masses, which gives rise to the theory that the starburst core is a very energetic and highly-dense environment. M82's unique bipolar outflow (or 'superwind') appears to be concentrated in two (2) of the clusters, and is fueled by energy released from supernovae within the clusters, occurring at a rate of about one every ten years.