M1 Crab nebula – first item in the Charles Messier catalogue. Messier was a comet hunter who created catalogue of fuzzy objects in the sky, so they will no longer be mistaken with comet. M1 nebula is supernova remnant in constellation of Taurus. It is pretty compact and quite bright and can be spotted with binoculars. Corresponding supernova was recorded by Chinese astronomers in 1054, and since then Crab nebula is expanding outward at about 1,500 km/s. M1 lies about 6,500 light years away in Perseus Arm of Milky Way. At the center of nebula lies the Crab Pulsar – a neutron star about 30km across that rotates over 30 times per second! 

Crab nebula structure is extraordinary – with increasing resolution more and more features and structures are visible. Hubble Space Telescope made the most feature rich images of M1 so far, but I also made (another) attempt this season. Over last two months I pointed telescope there for five times during selected nights with good seeing. However good seeing always came with bad transparency, so despite large amount of data, the overall image has quite low signal to noise ratio.

I made M1 Crab nebula images below with Meade ACF 10″ telescope and QHY163M camera on EQ6 mount at my suburban backyard observatory. First one is pure RGB image with mere 18:12:12 minutes of exposures. Another two images are compositions of RGB with additional hydrogen alpha channel (55×5 minutes) and oxygen II channel (25×5 minutes). 

M1 Crab RGB
Crab nebula – RGB channels. 42 minutes of total exposure time
M1 Crab HORGB composition
M1 Crab HORGB crop
M1 Crab HORGB enlarged crop

RGB large version https://astrojolo.com/wp-content/uploads/2018/02/M1RGB_DBE.jpg

HORGB large version https://astrojolo.com/wp-content/uploads/2018/03/2018-03-20-M1HORGB-2.jpg

Clear skies!

Image technical data: 

Date: January-February 2018 
Location: Nieborowice, Poland 
Telescope: Meade ACF 10" 
Corrector: AP CCDT67 
Camera: QHY163M, gain 0 
Mount: SW EQ6 
Guiding: SW 80/400 + ASI290MM 
Exposure: Ha 55x5, Oiii 25x5, RGB 18:12:12x1 minute 
Conditions: seeing good, transparency average-poor