Caldwell 48

NGC 2775

A spiral galaxy in Cancer

Magnitude: +10.2Diameter: 79,000 light years.
Apparent size: 4.2 arc minDistance: 64 million light years.

Caldwell 48 is a medium sized spiral galaxy but somewhat smaller than the Milky Way galaxy. My image shows the central core with just a hint of the tight spiral arms, which seem to start quite abruptly at the edge of the core. It has hosted five supernovae during the last thirty years, whilst we in the much larger Milky Way are waiting for our first one since Kepler’s Supernova (SN 1604), 417 years ago. ☹

I’ve only got a few days left before my convalescence period finally ends and hopefully I can get back to my telescope again, even if it is in moonlit skies.

Meantime, I was doing some background research on our next guest speaker, who will be talking to the Society about the proposed Laser Interferometer Space Antenna (LISA), a future space-based gravitational wave observatory. I stumbled on the following amazing video clip which gives one of the best animations of gravitational waves resulting from a merger of two black holes that I have seen.

It only runs for 31 seconds. I hope you enjoy it:

Feature image date:2021-04-03
Exposure:122 minutes (31x 236sec)
Field of View:48.4 x 32.2 arcmin

Location of Caldwell 48 and Constellation of Cancer

If the Astrometry images do not appear it is because the Astrometry website is sometimes off line.

Telescope & Imaging Details

SkyWatcher Esprit 120 mm apochromatic 3-element refractor; 840 mm f/l @ f/7.
Field flattener; ZWO Duo-band Hα (656nm) and [OIII] (500nm) filter.
SkyWatcher EQ6-R Pro mount; ZWO ASI120 guide camera.
Imaging camera: ZWO ASI 071 MC Pro (CMOS 28.4mm 16 Mpx).
Software: Telescope control: Cartes du Ciel, EQMOD, PHD2, Imaging: SharpCap, Gimp.
Observatory location: 34° South.

Thanks for reading!

Images © Roger Powell

I’m one of the founder members of Macarthur Astronomical Society and current webmaster.


    1. Both LIGO observatories are still functional. Now they are also collaborating with other smaller observatories around the globe but it is possible work is paused during the covid era, I’m unsure.

      A much bigger version, called LISA is proposed by the European Space Agency for launch in the 2030s. It will consist of three spacecraft in solar orbit, millions of kilometres apart.


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