Seyfert's Sextet
Right Ascension | 15:59:12 (h:m:s) |
---|---|
Declination | +20:45.5 (deg:m) |
Distance | (kly) |
Visual brightness | (mag) |
Apparent Dimension | (arc min) |
In 1951, Carl Keenan Seyfert (1911-1960) investigated a group of galaxies around NGC 6027 which is since known as Seyfert's Sextet (Seyfert 1951).
NGC 6027 had been discovered visually by Edouard Stephan, director of the Marseilles Observatory, in June of 1882, using an 80-cm (31.5-inch) reflector.
The image on the right was obtained by Adam Block, of the Advanced Observing
Program of Kitt Peak National Observatory's Visitor Center.
Credit: Adam Block/NOAO/AURA/NSF
Above image was obtained in July 1998 with the Kitt Peak National Observatory's
2.1-meter telescope, as part of the KPNO Research Experiences for Undergraduates
(REU) program. On the right image, the components are identified in this
picture, showing their designation in the Third Reference Catalogue of Bright
Galaxies (RC3) in upper case, the different labels used by Seyfert himself, and
the redshift in kilometers per second (from the RC3, as being the most
accurate). Note that different authors seem to like to relabel the components
(e.g. Hickson also uses a to e, but applies them to different parts of the
system).
Credit: REU program, N.A. Sharp/NOAO/AURA/NSF
Galaxies in Seyfert's Sextet:
PGC NGC NGC Hick- NGC RA (2000.0) Dec Size(') mag Type v_r v_r Seyf. RC3 son NED NED NED NOAO 56584 6027b 6027 H79c 6027B 15:59:10.8 +20:45:43 0.4x0.2 15.31 S0 Pec 4053 4413 56576 6027a 6027A H79a 6027A 15:59:11.1 +20:45:16 0.5x0.4 14.98 Sa pec 4237 4197 56578 6027c 6027C H79d 6027 15:59:11.8 +20:44:49 0.9x0.2 16.75 SB(s?)c pec 4620 4482 56575 6027 6027E H79b 6027E 15:59:12.5 +20:45:48 0.4x0.2 14.7 S0 pec 4447 4095 56580 6027d 6027D H79e 6027D 15:59:12.9 +20:45:35 0.2x0.2 16.47 SB(s)bc: pec 19809 19813 56579 6027e 6027B H79b1 6027C 15:59:14.5 +20:45:57 0.8x0.4 16.7 SB:0? 4095 4017Hickson and some other astronomers think that NGC 6027e (after Seyfert), his H79b1, may be a tidal extension of NGC 6027, his H79b, a cloud of interstellar matter ejected by its parent galaxy because of tidal interaction with its neighbors, and not a separate galaxy of its own.
Galaxy NGC 6027d produced one supernova, SN 1998fe which became about 18 mag bright.
Seyfert Sextett as photographed with the 48-inch Oschin Schmidt Telescope on Mt. Palomar, from the Digital Sky Survey [click for full 15'x15' image].
Seyfert's Sextett photographed by the Hubble Space Telescope
References.