3C 273 Quasar (Galaxy) in Virgo
How Far Can You See?
I was recently asked the question by a friend “How far have you seen with your
telescope?” I did not know the answer off the top of my head. He seem satisfied
when I side stepped the question and told him that by just using my eyes I once make
out the Great Sculptor Galaxy (NGC 253) during a night of perfect seeing from a
mountain top in the Hawaiian Islands. NGC 253 is 9.8 million light years which easily
sets my “without aid” long distance record (note, a light year is approximately 5.88
trillion miles or 9.5 trillion kilometers). Anyway, out of my own curiosity I started to
look through my past observational logs to see what the answer to his question was.
Quasar Q1634+706 turned out to be my record. I observed it from a dark location in
West Virginia, far away from city lights, with my 45.72 cm (18”) reflector. The light
from Q1634+706 observed that night left the quasar 8.6 billion years ago. But the
universe is receding fast at that distance and thus the quasar had traveled a lot since
it sent the light that I saw. Q1634+706 real distance was closer to 12.9 billion light
years. Unfortunately, I did not make a drawing of that observation. However, what
really surprised me was that my second place of the furthest objects I have seen
through a telescope was with a more modest-sized 155 mm (6.1") refractor from the
deck of my house. Considering that the sky over my house is light-saturated this
came as a surprise. The above drawing is of quasar 3C-273 made on February 15,
1999. The small dot just to the left of the 3C-273 label is the quasar. This quasar is
approximately 2.4 billion light years from the deck of my house. It shines 4 trillion
times brighter than our sun (visual magnitude = 12.9, absolute magnitude = -26.7).
The light I was seeing from my home deck that night left the quasar 2.4 billion years
ago – to me that is so cool.