Still TS65 420mm quad with tiny ASI462 planet camera. Using Optolong L-eNhance to add Ha and possibly Oiii to my two previous nights at this interesting motif.
Added the Dual Narrowband as two sessions in APP, first as RGB and then also as Ha!
M101 is a spiral galaxy in the constellation Ursa Major, also known as the Pinwheel Galaxy or NGC 5457¹. It is one of the nearest galaxies to the Milky Way, lying at a distance of about 21 million light years¹. It is one of the largest and most detailed galaxies visible from Earth, with a diameter of about 170,000 light years and a population of about a trillion stars¹².
M101 was discovered by Pierre Méchain in 1781, who communicated it to Charles Messier, who included it in his catalogue of nebulae and star clusters as object number 101¹ . It was later observed by William Herschel, who noted its spiral structure, and by Lord Rosse, who made several sketches of it¹ . It has been imaged by various telescopes, such as the Hubble Space Telescope, which revealed many details of its structure and dynamics¹ .
M101 has a high rate of star formation and hosts many regions of interstellar gas and dust, such as the giant H II region NGC 604, which is one of the largest and brightest nebulae in the Local Group¹². It also has several satellite galaxies, such as NGC 5474 and NGC 5477, which are gravitationally bound to it¹².
M101 has an apparent magnitude of 7.9 and an apparent size of 28.8 by 26.9 arc minutes¹. It can be seen with binoculars or a small telescope as a bright patch of light near the star Alkaid in Ursa Major¹ . It is best seen from the northern hemisphere during spring months.
Kilde: Samtale med Bing, 18.6.2023
(1) M101 – Wikipedia.
https://no.wikipedia.org/wiki/M101.
(2) Pinwheel Galaxy - Wikipedia.
https://en.wikipedia.org/wiki/Pinwheel_Galaxy.
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