Sky and Telescope - July 2017 - 84
FOCAL POINT by Stephen P. Cook
The Bright One That Got Away
Fifty years ago this month, the author, then 16, came a hair's breadth from making a huge discovery.
IN THE CONSTELLATION Delphinus
p The author in his backyard observatory the year he just missed eternal fame.
in locating S Del. As I found U and EU
Del, I noticed something near the top
of the 5° ﬁeld of the ﬁnder. It surprised
me to see a roughly 6th-magnitude
star there; I didn't recall anything that
bright forming such a nice equilateral
triangle with U and EU Del. It was
roughly 2° on a side.
I saw it as a 6th-magnitude interloper two nights earlier
- and I wasn't even looking for novae!
I secured my ﬁrst estimates of these
variables, at magnitudes 6.5 and 6.0,
respectively, on June 26th.
Around 12:20 PDT on the night
of July 6-7, I again pointed the 6×30
ﬁnder of my 6-inch Optical Craftsmen
reﬂector to the diamond of Delphinus,
above the avocado tree in my parents'
backyard. After checking my Skalnate
Pleso star atlas, I quickly found the pair
of 6th-magnitude stars I'd long used
J U L Y 2 0 1 7 * SK Y & TELESCOPE
Unfortunately, I remembered just
enough of my charts to judge my
magnitude estimates without referring
back to them, and I just assumed that
the questionable object belonged there.
I moved on to the next variable on my
list. In those days I often made more
than 30 variable-star magnitude estimates per hour, a pace that was perhaps
a little too fast for me to appreciate
Pre-discovery photographs put Nova
Del at magnitude 5.8 that night, and at
6.7 when I conceivably had an earlier
chance on June 26th.
I told this story the next summer to
my friend Douglas Duncan. Forty-two
years later - he was by then a University of Colorado astronomer and director of Fiske Planetarium, and still is
- he told me he often shared the story
as a lesson to his students. So after all
those years I had some consolation: My
failure was being used as an example of
the need to be careful and meticulous
in making observations!
¢ STEPHEN COOK, a former university professor and high school physics teacher, runs Project Worldview
(projectworldview.org) and does CCD
variable star photometry from his home
in Prescott, Arizona. In 2008, his old
Optical Craftsmen telescope helped in
the discovery of a new eclipsing binary
star (V1047 Persei).
COURTESY OF STEPHEN COOK
the Dolphin, on the evening of July 8,
1967, British observer George Alcock
discovered what became the brightest
nova in 25 years, peaking at magnitude
3.5. He spotted Nova Delphini 1967
(later designated HR Del) with binoculars after 800 hours of nova-searching
during the previous six and a half
years. While Alcock is rightly credited
with discovering this star, I saw it as a
6th-magnitude interloper two nights
earlier from my backyard observatory
in Burbank, California - and I wasn't
even looking for novae!
I was 16 that summer and had
become a proliﬁc variable star observer.
During the 1966-67 American Association of Variable Star Observers
observing year, I submitted over 5,200
magnitude estimates, fourth in the
world in the AAVSO's tally that year.
As the summer of 1967 began I added
two bright semi-regular variables to
my observing list, U and EU Delphini,
which were not part of the regular
AAVSO program. This seemed a logical
thing to do since they were near S Delphini, a long-period variable I'd made
17 observations of in the previous year.