"S5 0014+81" - Quasar
The quasar (QSO) "S5 0014+81" belongs to the best known quasars at all. It is located in the constellation Cepheus and with a declination of +81° it
is only 9° away from Polaris. So it is circumpolar in our latitudes and can be observed all year round, but best in summer and autumn.
The redshift of QSO is z=3.39, which puts it on rank 3 of the most distant known quasars that can be observed visually with a larger amateur
telescope. Only "B2 1422+231" and "APM 08279+5255" are even more distant. If you convert the redshift, you get a light travel time of 11.95 billion
years. The current distance, i.e. the "Comoving Radial Distance", is due to the expansion of the universe an almost unimaginable 22.4 billion light
years. And this increases with every second by another 270,000 kilometers. That is 90% of the speed of light.
That you can still see the quasar in this huge distance is because of its absolute magnitude of M= -31.5mag. This corresponds to a luminosity of almost
350 trillion suns. Even at a distance of 300 light years, the QSO would still shine as bright as our sun in the daytime sky. And even if you put the
quasar in the Andromeda galaxy, it would still be 2 magnitudes brighter than Venus. To produce this enormous luminosity, huge amounts of energy
are needed. Each year the quasar accretes a mass of 4,000 solar masses.
The black hole at the center of the giant elliptical host galaxy weighs in at about 40 billion solar masses, making it one of the heaviest supermassive
black holes known to date. The diameter of this "monster" is 240 billion kilometers. For comparison: the distance sun - Pluto is just 5 billion kilometers.
"S5 0014+81" therefore blows up all imaginable dimensions not only in mass but also in size. Of course these values have to be taken with caution,
because the mass has been determined only in an indirect way.
Another remarkable fact is that such a huge black hole already exists only 1.6 billion years after the big bang. This circumstance confronts many
physicists with the question, how a black hole could grow so fast in such a short time.
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But what can be seen of all this in a 20" telescope? The position of "S5 0014+81" is usually found quite fast. Furthermore it is located very favorable
between two brighter stars with 11 to 12mag. This makes it quite easy to fix the position of the quasar.
Nevertheless, even with 20" aperture and a magnification of V=270x the quasar was a bit shy. With averted vision it could be seen for a few seconds.
I estimated the brightness to be 16.0...16.5mag. So one needs enough aperture and good seeing to see the quasar properly.
Overall, for me the observation of "S5 0014+81" is one of the most exciting observations you can make with a larger telescope.
