Celestial Atlas
PGC 7500 - 7999 ←     PGC Objects: PGC 8000 - 8499 Link for sharing this page on Facebook     → PGC 8500 - 8999
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Page last updated Dec 2, 2016

For PGC 8000 - 8099, see below; for other PGC objects between 8000 and 8499, use these links: PGC 8100 - 8199 / PGC 8200 - 8299 / PGC 8300 - 8399 / PGC 8400 - 8499

PGC 8029 (= Markarian 1018)
A magnitude 13.9 lenticular galaxy (type S0? pec) in
Cetus (RA 02 06 16.0, Dec -00 17 29)
Physical Information: Based on a recessional velocity of 12720 km/sec, a straightforward calculation indicates that PGC 8029 is about 590 to 595 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 560 to 565 million light years away at the time the light by which we see it was emitted, about 575 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of about 1.2 by 0.85 arcmin (from the images below) for the main galaxy and its brighter extensions, the galaxy and its brighter extensions are about 195 to 200 thousand light years across (fainter extensions to the northwest span another 0.8 to 1.0 arcmin, so material is scattered over a region spanning 300 to 350 thousand light years). The brightness of Markarian 1018 has been sporadically varying (usually getting fainter but occasionally brighter) by as much as a factor of eight for years; the cause of this was recently shown (in late 2016) to be variation in the amount of material falling into a supermassive black hole at its center (which infall creates the radiation that justifies its classification as a Seyfert galaxy of type Sy 1.5). The reason for the varying rate of infall is unknown, but since the galaxy is almost certainly the result of a merger between two galaxies (as shown by the distorted shape of its outer regions), it probably has two black holes near its center, and one of them may be altering the distribution of material falling into the other.
SDSS image of region near lenticular galaxy PGC 8029, also known as Markarian 1018
Above, a 12 arcmin wide SDSS image centered on PGC 8029
Below, a 1.2 arcmin wide SDSS image of the galaxy
The starlike region at its center is actually radiation caused by a supermassive black hole
SDSS image of lenticular galaxy PGC 8029, also known as Markarian 1018
Below, a 1.5 by 2.0 arcmin wide image of the galaxy (Image Credit ESO/CARS Survey)
ESO image of lenticular galaxy PGC 8029, also known as Markarian 1018

PGC 8055 (=
NGC 822)

PGC 8066 (=
NGC 812)

PGC 8068 (=
NGC 824)

PGC 8093 (=
NGC 823 = IC 1782)
Celestial Atlas
PGC 7500 - 7999 ←     PGC Objects: PGC 8000 - 8499     → PGC 8500 - 8999