SkyandTelescope.com March 2014 37it very diffi cult to star-hop at 250× while referring back
and forth to maps — I sometimes had to retrace my steps
several times. It typically took at least an hour to get to
the right spot and fi nd the quasar, and sometimes even
longer. I often spent several nights recording, sketching,
and confi rming an observation. Refusing to succumb to
frustration was part of the “fun” of it.
The list on the facing page includes very brief observ-
ing notes. These may understate how challenging this is
from New Jersey, but I’m sure that I saw the ones noted.
For many of the quasars, even a small amount of sky haze
was enough to kill them, and a quasar could be invisible
on one night and then visible on another night.
Toward the end of the project, I realized that while
most quasars vary a few tenths of a magnitude in bright-
ness, some vary much more. 4C +29.45 should have beenTon 9512683LYNX8 h 50 m 8 h 40 mσ^3 σ^1σ9 h 00 m+34°+36°σ^2Star magnitudes657
8
9
10FIG. 5A, 5B, 5C
FILENAMES: QUASAR_TON951.AI, TON951_1DEG.JPG,
TON951_CROP.JPG
IMPORTANCE: ESSENTIAL
SPECIAL TREATMENT: AS FOR 2A, 2B, AND 2C, EXCEPT NO
CAPTION. LABEL TON 951 IN THE CIRCULAR IMAGE.Ton 951The word “quasar” was coined in 1964 as a short-
hand for “quasi-stellar radio source” — a bright,
concentrated radio source coinciding with an object
that looks like a star but has a very high redshift, indi-
cating that it’s moving away from us at a huge speed.
Today, the word is usually extended to include quasi-
stellar objects (QSOs) that have the same visual
properties as quasars, but aren’t bright radio sources.
Astronomers soon realized that quasars have many
features in common with Seyfert galaxies, which are
galaxies that have hyperluminous nuclei with unusual
spectral characteristics. According to current theory,
Seyferts and quasars are part of the same continuum,
members of the broader category of active galactic
nuclei (AGNs).
AGNs are supermassive black holes surrounded
by disks of matter (September 2013 issue, page 25).
These accretion disks emit huge amounts of radiation
as their material is pulled into the black hole. Many
AGNs also shoot out jets at relativistic speeds.Quasars are probably just like the nuclei of Seyfert
galaxies except that they’re brighter — often 100
times more luminous than all the host galaxy’s stars
combined. But the dividing line between quasars and
Seyferts is arbitrary. All the objects in our list have
been classifi ed as quasars in one or more studies, but
if you look at images of UGC 545 and RX J23273+1524,
you will see that both of them have prominent galac-
tic disks as well as pointlike nuclei. Most astrono-
mers would probably classify RX J23273+1524 as a
Seyfert and UGC 545 as a borderline case.
4C +29.45 (also known as Ton 599) is a blazar, a
quasar whose jet points straight at us, making it
appear much more luminous than it would if the jet
were aimed in a diff erent direction. Blazars are char-
acterized by extreme variability, sometimes brighten-
ing or dimming by a full magnitude in a single day.
See S&T April 2010, page 70, for other blazars
observable through backyard telescopes.
— Tony FlandersWhat’s a Quasar?
ESO / MARTIN KORNMESSERvisible at its listed magnitude of 14.4, but I tried it fi ve
times without seeing it. Checking the Frankfurt Quasar
Monitoring website, I discovered that this object (also
called Ton 599) varies wildly on time scales ranging from
minutes to years. It reaches 14th magnitude fairly often,
but it’s usually 15th or 16th magnitude, and it has been
observed as faint as magnitude 18.5!
I personally plan to try to run through my list again
now that I’ve had the mirror on my 16-inch refi gured and
I’ve psychologically recovered from all the fun of the fi rst
round of trying. I’ll try for some of the quasars I missed,
and maybe expand the list to include some fainter qua-
sars. I hope that my experience inspires you to look for a
few quasars yourself. Good hunting! ✦Bob Cava is a professor of chemistry at Princeton University
specializing in high-temperature superconductors.Obs Quasars2.indd 37 12/23/13 11:34 AM