M27 Dumbbell (aka Apple Core Nebula) was the first planetary nebula to be discovered (in 1764 by Charles Messier). From his notes he reports:
I have worked on the research of the nebulae, and I have discovered one in the constellation Vulpecula, between the two forepaws, and very near the star of fifth magnitude, the fourteenth of that constellation, according to the catalog of Flamsteed: One sees it well in an ordinary refractor of three feet and a half. I have examined it with a Gregorian telescope which magnified 104 times: it appears in an oval shape; it doesn’t contain any star; its diameter is about 4 minutes of arc. I have compared that nebula with the neighboring star which I have mentioned above [14 Vul]; its right ascension has been concluded at 297d 21′ 41″, and its declination 22d 4′ 0″ north.
M27 is easily visible in binoculars and any other visual instrument. Nebula is placed at distance 1360 light years. Its expansion velocity was measured for 31km/s, and that implies the kinematic age is about 9,800 years.
Its central star mass was estimated to be 0.56 of Solar mass. It is extremely hot blueish subdwarf star, which emits primarily energetic radiation in the non-visible part of electromagnetic spectrum.
M27 is a special nebula for me. It was the first target I imaged using electronic sensor. It was seven years ago, and the sensor was in the Canon 20D camera. These seven years passed very quickly for me.
Image technical data: Date: July-August, 2018 Location: Nieborowice, Poland Telescope: Meade ACF 10" Corrector: AP CCDT67 Camera: QHY163M, gain 100 Mount: SW EQ6 Guiding: SW 80/400 + ASI290MM Exposure: Ha:Oiii 100:30 x 5 minutes, RGB 50:30:40 x 30 seconds Conditions: seeing average-good, transparency average-good
PS – this image became Image of The Day on 19.09.2018 at AstroBin portal 🙂