Sky & Telescope - January 2025 - 24

CRL 618: ESA / HUBBLE / NASA; WESTBROOK: MICHAEL WERNER / PALOMAR OBSERVATORY
Awesome Auriga
WESTBROOK'S NEBULA This curious object
is in an energetic and short-lived phase in
the later stages of a star's life just before
evolving to a planetary nebula. Using
archival data, astronomers noted that
CRL 618 had brightened by about
two magnitudes between 1940
and 1975. They pinpointed the
start of the planetary nebula
phase to around 1971,
when Bill Westbrook
discovered it.
Plus, I can even detect Simeis 126 - a faint glow that extends
0.5° west of Espin 170 before turning south!
AE Aurigae is a massive O-type star ionizing the surrounding
interstellar cloud as it moves northward at a rate
of more than 4″ a century. Fascinatingly, it used to form a
binary pair with fellow O-type star Mu (μ) Columbae in the
Trapezium Cluster - it seems they were ejected from the
Orion Nebula about 2.5 million years ago . . . but in opposite
directions! These types of stars have since become known as
runaway stars.
To me, the most interesting object on our tour is the one
N
that bears the name of a man who has almost been forgotten.
The object is a pre-planetary nebula that was discovered in
the early 1970s by the young California Institute of Technology
graduate student William Westbrook. He found it while
engaged in a study of previously unidentified bright infrared
sources discovered in the Air Force Cambridge Research Laboratory's
rocket-borne survey. Known commonly as Westbrook's
Nebula and cataloged as CRL 618, the astronomer
studied it with many of the largest telescopes of the day and
found it to be the most interesting of them all. He postulated
that it was " an extremely young planetary nebula, perhaps
still in the process of formation. "
Using my 10-inch, the eastern half of CRL 618 is just visA
Forgotten Man
Tragically, William Westbrook died of cancer at the
age of 25 (in 1975) shortly after submitting his paper
on CRL 618 for peer review, leaving behind not only
grieving family and colleagues, but also his wife,
Joanne. A few years before they met at a school
dance in 1968, he developed symptoms that doctors
attributed to a tumor in his left lung - rhabdomyosarcoma,
a rare type of cancer that forms in soft tissue
mostly in children and adolescents.
Bill and Joanne married in 1971, hoping the cancer
wouldn't return as he continued to undergo chemotherapy.
He was a major force in the Caltech Infrared
Lab and developed most of the equipment himself for
the observations in his doctoral thesis. Joanne, whom
I was fortunate to interview in 2023, remembered that
he " had red hair and blue eyes, [was] always upbeat
and jolly . . . and always engaged
in . . . some project,
studying something. "
BILL WESTBROOK This
image, taken in the early 1970s,
shows him standing outside the
doorway of the " Monastery, "
the small dorm where visiting
astronomers stayed at Palomar
Observatory.
ible as a (by my estimate) 16.3-magnitude speck 4.1° northwest
of Iota Aurigae, right at the border with Perseus. In my
16-inch at 440×, the eastern half is a nonstellar spot that
with study seems to extend and fade to the west, reminding
me of the pre-planetary nebula Minkowski's Footprint (see,
e.g., S&T: June 2021, p. 57).
Go Far, Grow Close
Since we're in western Auriga, let's drop south to the globular
cluster Palomar 2. It lies almost 3° southwest of Iota
Aurigae and was first discovered in the 1950s on National
Geographic - Palomar Observatory Sky Survey plates. But having
to look out 85,000 light-years and through two of our galaxy's
spiral arms (the Perseus and Norma/Outer Arm) has
left us with a much dimmer view. In fact, if its light wasn't
obscured by nearly three full magnitudes, the globular would
be visible in binoculars!
That being said, it's visible in my 5.1-inch scope at 59×.
With a detailed chart in hand, care and patience revealed this
outer-halo cluster while directly overhead on a dark night.
It appeared as a small, ghostly glow 2.2′ west-southwest of a
13.3-magnitude star. It's much easier in my 10-inch at 135×,
where it's a mere 1.5′-wide glow.
Over the past couple of years, I've managed to observe
three supernova remnants in Auriga using various telescopes.
But I honestly can't tell you which one is the brightest since
it's a subjective matter when it comes to such large nebulae.
Instead, I'm going to focus on HBH 9 (SNR G160.9+2.6),
which was the first one discovered that is wholly within the
constellation and currently the one I've seen with the smallest
aperture.
24 JANUARY 2025 * SKY & TELESCOPE
Sky & Telescope - January 2025

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