Sky & Telescope - USA (2020-06)

(Antfer) #1
challenge even for an amateur astrono-
mer equipped with a large Dobsonian
telescope. Could my relatively modest
11-inch SCT show any hint of these
dim sprites? I placed a red fi lter over my
monitor’s screen so as to avoid annoy-
ing nearby observers and got to work.
Not only did my video camera reveal
HCGs, it showed detail where there
was detail to be seen. For example, the
16th- to 18th-magnitude members of
HCG 20 displayed some haze and hints
of tiny galactic disks. The dark sky at
the site allowed me to increase my
exposure times to a full 10 seconds and
set the gain to near maximum, without
making the resulting images excessively
noisy or overexposed.
The next morning, I reviewed the
video sequences I’d recorded and was
astounded to discover my images
showed essentially the same details
as those captured by the famed 48-inch Oschin Schmidt
Telescope at Palomar Observatory. There wasn’t much in the
observatory’s online Digitized Sky Survey images that wasn’t
visible in my shots.
Video again proved its value when I used it for much of my
observing during the Herschel Project (S&T: Aug. 2012, p. 60),
my quest to observe the roughly 2,500 deep-sky objects discov-
ered by Caroline and William Herschel. While I did some of
the project visually, most had to be done from my backyard or
the light-polluted skies at my club’s site. Video easily brought
home my quarry even under those compromised condi-
tions. While I’d upgraded to the color MallinCam Xtreme

by the time I was halfway through the
Herschel Project, even my old black-
and-white camera was able to grab the
dimmest object on the list, the magni-
tude-16.4 galaxy NGC 4549.
Since such a faint galaxy was little
challenge for video, I began to wonder
just how far the technology could take
me. Looking at my frame grabs, I noticed a horde of tiny,
distant PGC and UGC galaxies. Might video transport me
beyond them? Could I claim the mind-blowing, ultimate prize
of quasars? These ancient objects are relics of the earliest
epochs of the universe. Were they within reach?
They were, as I found out one evening at my favorite
observing site, the Chiefl and Astronomy Village near the dark
Gulf Coast of Florida. I’d prepared for my observing run by
making a list that included objects down to magnitude 17.
Quasar after quasar appeared on my screen. At the end of
the night, as I was covering the scope, I stopped and thought
about what I’d seen. While the images weren’t very exciting —
quasars look much like stars in photographs — these objects
have distances measured in billions of light-years.
Is there a downside to using video at the telescope? Sure.
The technology might not be for you if you like to keep things
simple in the fi eld. You won’t only be dealing with a com-
puterized Go To telescope, but also with a video camera, a
monitor, and all their associated cables and power require-
ments. Most of my video observing runs have been amazingly
successful, but there have also been nights in which I spent
hours troubleshooting equipment problems.
However, if you long to see detail in deep-sky objects from
your backyard with a modest telescope, video can make that
possible and show more than can be seen in an eyepiece on
even the fi nest nights. Perhaps best of all, video can take you
deeper into the cosmos than you may have ever imagined —
even to the frighteningly distant realm of the quasars.

¢ ROD MOLLISE is a retired engineer, author, and Sky & Tele-
scope Contributing Editor. When he’s not observing the deep
sky from his backyard, Rod keeps busy teaching part-time for
the physics department at the University of South Alabama.

Electronic Observing


70 JUNE 2020 • SKY & TELESCOPE


qLOST IN THE LAGOON One of the great pleasures of video astrono-
my is the ability to leisurely enjoy the sights (such as the Lagoon Nebula,
M8) in complete comfort.

tDISTANT BEACON (Top) Given that a
magnitude-16.4 galaxy was little challenge for
video, the author decided to collect superno-
vae in distant galaxies with his 8-inch SCT and
video camera. This image shows a supernova
that was discovered in M82 in 2014 (indicated).

tFAR, FAR AWAY (Bottom) Among the most
distant objects the author has observed is the
gravitationally lensed double quasar (QSO
0957+561 A/B) in Ursa Major. Although ap-
pearing as an unimpressive dot on the display
screen (and in this image), the light reaching
his video camera had been travelling across
space for some 7.8 billion years.
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