Mrk 817 - Seyfert Galaxy
Mrk 817, also known as Markarian 817, is a barred spiral galaxy in the constellation Draco. It was discovered during a sky survey
conducted by the Armenian astrophysicist Benjamin Markarian in the 1960s. The aim of his investigation was to identify galaxies
with strong ultraviolet emissions.
Mrk 817 is a Seyfert galaxy whose active galactic nucleus (AGN) is powered by a supermassive black hole at its center, which
has an estimated mass of around 40 to 80 million solar masses. The galaxy is located about 430 to 456 million light-years away
from Earth and has a diameter of about 80,000 light-years - it is therefore slightly smaller than our own Milky Way.
What makes Mrk 817 particularly interesting are the strong, variable winds emanating from its central black hole. These winds
eject gas and matter into space at speeds of several million kilometers per hour. This has the effect of suppressing star formation
in the affected regions.
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In my 20" telescope, Mrk 817 was visible as a brighter star surrounded by a faint, diffuse halo. Not particularly exciting to look at,
but from a physical perspective, it was.
