Galaxies
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A Deep View of Dwarf Spiral Galaxy NGC 3109
This deep image shows the unusual galaxy NGC 3109, located 4.34 million light years away in the direction of the constellation of Hydra.
NGC 3109 is a dwarf barred spiral galaxy, similar to the Large Magellanic Cloud, and has an approximate diameter of 25,000 light years. It is oriented almost edge-on from our vantage point and contains a large amount of hydrogen gas. For this image I collected over 14 hours of H-Alpha exposure in addition to the LRGB, and as a result the hydrogen clouds are clearly visible as spectacular red HII emission regions scattered throughout the galaxy. The emission is caused by vigorous star formation and many blue giant stars and clusters are visible in the galaxy. It also hosts an unusually high number of planetary nebulae and a significant amount of dark matter but does not seem to have any well defined galactic nucleus.
NGC 3109 was discovered from South Africa by John Herschel on March 24, 1835. It is a member of the Antlia-Sextans Group which also includes the very small Antlia Dwarf galaxy. Studies of the gas in the Antlia-Sextans group members indicate that NCG 3109 and the Antlia Dwarf had a gravitational interaction in the past, about 1 billion years ago.
The group is thought to be either the most distant members of our Local Group of galaxies, or perhaps be the nearest other galaxy group outside of the Local Group.
Image details:
Date: Feb 2019 - May 2020
Exposure: LRGBHa: 1240:175:160:165:855 mins, total 46 hours @ -25C
Telescope: Homebuilt 12.5" f/4 Serrurier Truss Newtonian
Camera: QSI 683wsg with Lodestar guider
Filters: Astrodon LRGB E-Series Gen 2
Taken from my observatory in Auckland, New Zealand
