"PG 1715+535" - Quasar
The quasar "PG 1715+535" is located like many other distant quasars in the constellation Draco. The light travel time can be calculated from the redshift
of z=1.94 to 10.4 billion years. Due to the expansion of the universe the current distance is even 17.1 billion light-years and every second another 235,000
kilometers are added. So PG 1715+535 is moving away from us with 78% of the speed of light.
But not only the large distance makes "PG 1715+535" a very exciting object. If you look at the quasar on an image of the SDSS, you can see another faint
point of light at a distance of about 5 arcseconds. Unfortunately I could not find out if this is a lensed double image of the quasar. But it looks very interesting.
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Accordingly I was excited when I started to search for "PG 1715+535" with my 20" f/3.2 Dobson. Although brighter field stars are missing in the immediate
vicinity of the QSO, it is located in the middle of a brighter star triangle. So the position can be pinned down quite well.
At 270x I could first see a faint star. After some time it appeared elongated and towards the end of the observation I could separate it in moments of very good
seeing. But this was not an easy thing.
Overall "PG 1715+535" is a very interesting object for larger telescopes with 16" aperture and more.
