NGC 2442-3. The Meathook galaxy

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NGC 2442 and NGC 2443 are just two fragments of the same galaxy. The northernmost arm (the longest, here depicted on the lower left) is called NGC 2443 and the southernmost arm (upper right) is NGC 2442. This galaxy is located at about 50 million light years away in the southern constellation Volans. The distorted stricture of this galaxy is the result of a gravitational encounter with the galaxy AM 0738–692, that can be seen in the wider image below, at its lower right. This encounter triggered a high star formation rate (SFR) on the arms.


According to a revealing paper by Mihos and Bothun in 1997, both galaxies had this encounter about 250 million years ago and they expected both galaxies to experience one or more additional close passages and, eventually, merge. Later on, in 2010, Pancoast et al.  determined two new, important aspects of this galaxy: on one side, the SFR is higher, at least twice, than the determined before by Mihos/Bothum. Secondly, there is a gas superbubble located outside of the main arms (here marked with a white circle) where a much higher SFR is detected and that seems to be the result of the accumulation of the gas expelled by hundreds of supernova explosions. Specifically, the SN1999ga was detected on one of the edges of this superbubble. Additionally, star streams, built up at the encounter, can be spotted at the ends of both arms.


Additional Information


Name(s): NGC 2442-NGC 2443. Meathook Galaxy. Cobra and Mouse Galaxy

Type: Barred Spiral galaxy

RA:  07h 36m 24s

Dec: -69º 31’ 51”

Constellation: Volans

Size (arcmin): 6×5 arcmin

Magnitude: +11.2

Distance: 50 Mly


Date: 2023-01-30 to 2023-02-16

Location: Obstech, Río Hurtado, Chile

Size (arcmin): 15×14 arcmin

Telescope: 24” f/6.5 Reflector

Camera: QHY 461 (11760x8896pix)

Guiding: off-axis guider

Total exposure: 13h 10 m (L: 5h 40m; RGB: 7h 30m)

Processing: CCDStack, PixInsight (one process) and Photoshop CC 2023


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