The Flaming Star Nebula in Auriga (top left) with the Tadpole Nebula (bottom middle) and Spider and Fly (bottom left). A widefield (5×3 degree) SHO-image. Telescope: Askar FRA600+0.7x reducer, Mount: AM5N, Camera: ASI6200MC, Askar D1+D2 filters: 97x180s D1, 87x180s D2, Processing: PixInsight. Nigel M. Price
The Flaming Star Nebula (IC405) in Auriga (Top right of image): IC405 is an emission line and reflection nebula shown here in false colour with Sulphur II shown as red (normally red), Hydrogen alpha shown as green (normally deep red), and Oxygen III shown here in blue (but is really green in a true spectrum). This is the common way of displaying these ionised elements by convention after the Hubble Space Telescope palette. The colours really show us the conditions of the gas, for example the oxygen requires more intense UV radiation to ionise it.
In the middle of the nebula you can see the bright star AE Auriga which is ionising the nebula as it passes through the cloud. AE Auriga has been shown to be a star that originated in the middle of the Trapezium cluster but was ejected in a binary-binary encounter that flung it wide into Auriga. It is passing through at supersonic velocities and will have passed through completely in another 20,000 years or so. The nebula is approximately 5 light years across and lies at a similar distance to Orion at 1500 light years. Discovered by John Schaeberle in 1892.(Ref Hidden Universe 2022, Charles Bracken and Max Whitby).
Tadpole Nebula (IC410) in Auriga (Bottom middle of image): IC410 is a dusty emission nebula located in the constellation of Auriga at about 12.000 ly from Earth. The gas structures in this picture are lit by the radiation from the open star cluster NGC 1893 that lies in the center of the nebula. This star cluster is about 4 million years old, but in astronomical terms it is still very young, with hot, massive stars. At the top-left of the star cluster two more dense structures are visible. These are similar to the famous Pillar of Creation and they are composed of dust and gas leftover from the formation of the star cluster and are very likely to give birth to more stars in the future. As can be seen in the picture, these structures point away from the center of the nebula. This is because of the stellar winds and radiation pressure from the stars in NGC 1893. The nebula takes its nickname from these structures’ shape (Ref SKY and TELESCOPE January 19, 2017). Discovered by Max Wolf in 1892.
Spider (IC417, Sh2-234) and Fly (NGC1931,Sh2-237) Nebulae in Auriga (Bottom left of image): IC417, or the Spider is an emission nebula approximately 100 light years across located about 10,000 light years from Earth. It is in the outer part of the Milky Way, almost exactly in the opposite direction from the galactic center. It is a hotbed of new star formation so many more hot young stars can be seen in the infra-red (not shown here). (https://app.astrobin.com/i/ehc4ly and https://www.nasa.gov/image-article/spider-nebula/).
The Fly nebula (Sh2-237) is a mixed emission/reflection nebula. It contains the hot young cluster NGC 1931 is a reflection and emission nebula and around a young Trapezium like star cluster which is around 2 million years of age, most of the ongoing star formation in the star cluster is hidden away in the nebula. It is believed that the main ionizing source for the dusty molecular cloud is a single, hot B-type star. The distance from Earth is estimated at 7500 light years. The German-born English astronomer William Herschel discovered the small reflection nebula in 1793 and noted seeing a few stars in the middle. In 1931, Swedish astronomer Per Collinder included it in his catalog of open star clusters as the “nebulous cluster” Collinder 68. American astronomer Stewart Sharpless cataloged the emission component, which lies outside the center, as Sh 2-237 in 1959.(Ref: https://en.wikipedia.org/wiki/NGC_1931).
Messier 36 (cluster bottom left corner of image) Messier 36 or M36, also known as NGC 1960 or the Pinwheel Cluster, is an open cluster of stars in the somewhat northern Auriga constellation. It was discovered by Giovanni Batista Hodierna before 1654, who described it as a nebulous patch. The cluster was independently re-discovered by Guillaume Le Gentil in 1749, then Charles Messier observed it in 1764 and added it to his catalogue. It is about 4,340 light years away. The cluster is very similar to the Pleiades cluster (M45), and if as far away it would be of similar apparent magnitude. It is estimated to be 25 million years old with a mass approx 75o times that of the sun with a diameter of approx 35 light years (ref: https://en.wikipedia.org/wiki/Messier_36).
Messier 38 (cluster top left of image) Messier 38 or M38, also known as NGC 1912 or Starfish Cluster, is an open cluster of stars in the constellation of Auriga. It was discovered by Giovanni Batista Hodierna before 1654 and independently found by Guillaume Le Gentil in 1749. It is approx. 3,480 light years away. The cluster’s brightest stars form a pattern resembling the Greek letter Pi. It is approximately 13 light years in diameter with an intermediate age at about 290 million years. From the population of about 100 stars, this open cluster features a prominent yellow giant with the apparent magnitude +7.9 and spectral type G0 as its brightest member, a luminosity of 900 Suns. For comparison, the Sun would appear as a faint magnitude +15.3 star from the distance of M38.
Dr Nigel Price