M66 - Barred Spiral Galaxy in Leo
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Messier 66 (M66), also cataloged as NGC 3627 or Arp 16, is one of several spiral galaxies that grace the spring skies in the constellation Leo. Located about 36 million light-years (≈11 Mpc) from Earth, it was discovered on March 1, 1780, by Charles Messier.
Observations
April 26, 2025, around 2:00 AM – Jaworzno, Poland
Conditions: high light pollution
The night was clear, although the sky appeared slightly hazy. Toward the end of the session a few isolated clouds drifted through, but they did not hinder the observations.
M66 is part of the famous Leo Triplet (Arp 317) — a tight group of three gravitationally interacting galaxies that also includes M65 and NGC 3628 (Photo 1).
Spanning nearly 96,000 light-years across, M66 exhibits well-defined spiral arms rich in interstellar dust. Along those arms lie numerous bright clusters of young stars, proof that vigorous star formation is still under way. The arms, however, are noticeably asymmetric: one side of the disk appears more stretched and distorted, hinting at past or ongoing gravitational encounters with neighboring galaxies.
Several supernovae have been recorded in M66. SN 1973R and SN 1989B were classic stellar explosions, whereas SN 1997bs turned out to be a likely impostor — a stellar outburst that initially appears to be a supernova but does not destroy its progenitor star. The most recent event, SN 2009hd, again confirmed that M66 still harbors young, massive stars destined for spectacular endings.
Photo 1 Parameters:
- Total exposure time: 90 minutes (stack of 90 RAW frames at 60s each, using an appropriate number of dark, bias, and flat frames)
- ISO: 1600
- Maksutov-Cassegrain telescope (100/1400), prime focus exposure
- A filter was used to reduce the effects of artificial light pollution and atmospheric glow
- Mount: equatorial mount with tracking, aligned using the drift method and controlled by a custom-built system.
Further readings:
- Duan Z., Multicolor Photometry and Stellar Population Synthesis Study of the Interacting Galaxies of the Leo Triplet, The Astronomical Journal, 2006, 132(4), pp. 1581-1592
- König M., Binnewies S., Bildatlas der Galaxien: Die Astrophysik hinter den Astrofotografien, Kosmos, 2019
- van den Bosch R. C. E., et al., Hunting for Supermassive Black Holes in Nearby Galaxies With the Hobby-Eberly Telescope, The Astrophysical Journal Supplement Series, 2015, 218(1), p. 13
Marek Ples