Positioned in Serpens Caput, a constellation with few deep-sky objects, Seyfert’s Sextet was one of many first compact galaxy teams ever famous. That occurred in 1948, when astronomer Carl Seyfert found that the beforehand cataloged NGC 6027 was really multiple object. His Sextet turned the densest group of galaxies recognized on the time.
Seyfert’s preliminary statement described six galaxies shut collectively, however that isn’t the case. Later observations revealed solely 4 interacting galaxies (NGC 6027 and NGC 6027a, b, and c) at a distance of 190 million light-years. A fifth galaxy, NGC 6027d, is definitely 410 million light-years behind the group. And the sixth galaxy isn’t a galaxy in any respect — it’s a plume of stars generated by interactions between NGC 6027 and NGC 6027a. The galaxies have diameters that vary from 0.9′ to 0.2′.
The 4 bodily related members are galactic Lilliputians. Astronomers imagine your entire group would match contained in the width of the Milky Way, some 100,000 light-years. Three share a standard halo that in most galactic collisions would generate new star formation, however not right here. Maybe which means inside the subsequent a number of billion years, the galaxies may merge and type a big elliptical galaxy.
Edouard Stephan found NGC 6027 in 1882, however didn’t resolve the others. This extremely inclined barred lenticular galaxy is the group’s brightest member at magnitude 14.7. NGC 6027a is magnitude 14.9. Maybe the darkish lane of this Sa peculiar spiral dims it somewhat. It’s a tiny model of the Sombrero Galaxy (M104). NGC 6027b is analogous in measurement and nature to NGC 6027 however is a more difficult magnitude 15.3. NGC 6027c is by far the group’s faintest member at magnitude 16.7. It’s a extremely inclined SBc or SBd galaxy. Hubble photographs present it’s wealthy in younger blue stars however poor in HII areas. Past the true group, NGC 6027d is a huge face-on barred spiral greater than 800 million light-years away. At magnitude 16.5, it’s a problem.
Observing Seyfert’s Sextet requires a big telescope. You may glimpse it in a 13-inch telescope beneath glorious skies, however resolving members requires extra aperture, magnification, and a really regular ambiance.
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