Robin
June 3rd, 2021, 05:20 PM
Hi everyone,
A while ago, after observing Markarian 231, I took a look at some literature to learn more about quasars and to try to find out whether or not there are quasars, whose host galaxies can be observed visually. There is a "Catalogue of quasars and active nuclei: 13th ed.", published by M.-P. Véron-Cetty and P. Véron in 2010, which contains an impressive database of quasars, blazars and active galactic nuclei objects:
https://www.aanda.org/articles…a14188-10/aa14188-10.html
http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/518/A10
They define a quasar as follows:
-starlike object or object with starlike nucleus
-with broad emission lines
-that is brighter than absolute magnitude Mblue = -22.25 mag
Please also refer to this discussion:
https://www.deepskyforum.com/showthread.php?1480-Markarian-231
Earlier this week I was able to observe three objects from this list:
PGC 54701 = MCG+11-19-006 (UMi, 15.4 bmag, 0.9' x 0.6', type E, 620 million Ly)
According to data from Simbad its absolute blue magnitude would be -21.2 Mag. But even if it is fainter than the criterion above, physically it still is a very interesting object.
In my 20" Dobsonian at 419x magnification I saw an elongated galaxy without structure, but with a stellar nucleus.
NGC 6166 (Her, 11.8 mag, 2.1' x 1.5', type E, 410 million Ly)
Absolute blue magnitude -22.7 Mag according to Simbad. Wow this is an NGC galaxy categorized as a quasar according to this paper. It is also called 3C 338.
In my 20" Dobsonian at 419x magnification I saw a large and elongated galaxy with a diffuse outer area. The center area was mottled, sometimes I thought I saw something stellar in the center. But it doesn't look like a nucleus way brighter than the remainder of the galaxy.
It is a lot of fun to observe so many of these members of Abell 2199 galaxy cluster around NGC 6166.
PGC 100408 = NPM1G+27.0587 (Lyr, 14.9 bmag, 0.6' x 0.4', type Sb, 850 milllion Ly)
According to data from Simbad its absolute blue magnitude would be -22.4 Mag, bright enough to be called a quasar according to the definition above.
In my 20" Dobsonian at 419x magnification I observed a homogeneous and elongated smudge with a stellar center. Its appearance is rather similar to Markarian 231, but its absolute magnitude is more luminous.
Please find attached my sketches of these objects.
Clear skies
Robin
A while ago, after observing Markarian 231, I took a look at some literature to learn more about quasars and to try to find out whether or not there are quasars, whose host galaxies can be observed visually. There is a "Catalogue of quasars and active nuclei: 13th ed.", published by M.-P. Véron-Cetty and P. Véron in 2010, which contains an impressive database of quasars, blazars and active galactic nuclei objects:
https://www.aanda.org/articles…a14188-10/aa14188-10.html
http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/518/A10
They define a quasar as follows:
-starlike object or object with starlike nucleus
-with broad emission lines
-that is brighter than absolute magnitude Mblue = -22.25 mag
Please also refer to this discussion:
https://www.deepskyforum.com/showthread.php?1480-Markarian-231
Earlier this week I was able to observe three objects from this list:
PGC 54701 = MCG+11-19-006 (UMi, 15.4 bmag, 0.9' x 0.6', type E, 620 million Ly)
According to data from Simbad its absolute blue magnitude would be -21.2 Mag. But even if it is fainter than the criterion above, physically it still is a very interesting object.
In my 20" Dobsonian at 419x magnification I saw an elongated galaxy without structure, but with a stellar nucleus.
NGC 6166 (Her, 11.8 mag, 2.1' x 1.5', type E, 410 million Ly)
Absolute blue magnitude -22.7 Mag according to Simbad. Wow this is an NGC galaxy categorized as a quasar according to this paper. It is also called 3C 338.
In my 20" Dobsonian at 419x magnification I saw a large and elongated galaxy with a diffuse outer area. The center area was mottled, sometimes I thought I saw something stellar in the center. But it doesn't look like a nucleus way brighter than the remainder of the galaxy.
It is a lot of fun to observe so many of these members of Abell 2199 galaxy cluster around NGC 6166.
PGC 100408 = NPM1G+27.0587 (Lyr, 14.9 bmag, 0.6' x 0.4', type Sb, 850 milllion Ly)
According to data from Simbad its absolute blue magnitude would be -22.4 Mag, bright enough to be called a quasar according to the definition above.
In my 20" Dobsonian at 419x magnification I observed a homogeneous and elongated smudge with a stellar center. Its appearance is rather similar to Markarian 231, but its absolute magnitude is more luminous.
Please find attached my sketches of these objects.
Clear skies
Robin