210113 - M33 "Triangulum" galaxy
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click image to enlarge
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ASTRO:
type=Spiral galaxy const=Triangulum mag=5.7 dist=2.7 M ly size=60k ly IMAGE: location=EB Driveway BrtlCls=4 moon=1% WxCr exposure=DSLR OSC: 39x240s (2.6h), ISO1600 EQUIPMENT: camera=Nikon D90 (mod) optics=ES102 w0.8x rdcr. eff. F=571mm, f/5.6 filter=Optolong L-Pro LPS mount=Celestron AVX guiding=Orion 60x240mm, ZWO ASi224MC SOFTWARE: acquisition=Stellarium, APT, PHD2, processing=PixInsight, PhotoshopCC, LrC |
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The Triangulum Galaxy is a spiral galaxy located appx 2.7 M light-years (ly) from Earth in the constellation Triangulum. It is catalogued as Messier 33 (or M33), and NGC 598. It is the third-largest member of the Local Group of galaxies, behind the Andromeda Galaxy and the Milky Way, and is one of the most distant permanent objects that can be viewed with the naked eye.
Triangulum is the smallest spiral galaxy in the Local Group (although the smaller Large and Small Magellanic Clouds may have been spirals before their encounters with the Milky Way), and is believed to be a satellite of the Andromeda Galaxy, or on its rebound into the latter due to their interactions, velocities, and proximity to one another in the night sky. It also has an H-II nucleus.
Under exceptionally good viewing conditions with no light pollution, the Triangulum can be seen with the 20/20 vision naked eye. To those viewers, it will sometimes be the farthest permanent entity visible without magnification. Observers range from finding the galaxy easily visible by direct vision in a truly dark sky to needing to use averted vision in rural or suburban skies with good viewing conditions in low light pollution. It has been chosen as one of the critical sky marks of the Bortle Dark-Sky Scale (a scale system for measuring light pollution near and in urban skies), supported by its relative invariability, reasonable northern declination and brightness.
Triangulum is the smallest spiral galaxy in the Local Group (although the smaller Large and Small Magellanic Clouds may have been spirals before their encounters with the Milky Way), and is believed to be a satellite of the Andromeda Galaxy, or on its rebound into the latter due to their interactions, velocities, and proximity to one another in the night sky. It also has an H-II nucleus.
Under exceptionally good viewing conditions with no light pollution, the Triangulum can be seen with the 20/20 vision naked eye. To those viewers, it will sometimes be the farthest permanent entity visible without magnification. Observers range from finding the galaxy easily visible by direct vision in a truly dark sky to needing to use averted vision in rural or suburban skies with good viewing conditions in low light pollution. It has been chosen as one of the critical sky marks of the Bortle Dark-Sky Scale (a scale system for measuring light pollution near and in urban skies), supported by its relative invariability, reasonable northern declination and brightness.