Sky & Telescope - January 2020 - 55

SE A N WA LK ER / S&T

u The nebula IC 410 and its embedded star
cluster NGC 1893 are gorgeous in this color
image. The author saw the southern Tadpole
(Simeis 130) through her 10-inch reflector, but
not the fainter northern Tadpole, Simeis 129.

mirror-imaged view, I faintly see a 1½°
J of nebulosity, especially when I scan
east-west across it. The J dangles upside
down in the sky, but only the bright
region in its hook forms the Flaming
Star Nebula.
Now lets move eastward to the 5thmagnitude star Phi (ĳ) Aurigae. Phi
gleams in the smile of a 1.5° asterism
that New York amateur Ben Cacace
dubbed the Cheshire Cat. There
are six stars in the wide grin, tipped
north-northeast, and two eye stars to
their west. Phi and the northern eye
both glow yellow-orange in my 105mm scope at 17×. Since the vanishing
cat's dimmest star is magnitude 6.9,
the asterism is an easy target for most
binoculars.
The opulent open cluster Messier 38
decorates the northern corner of the
Cheshire Cat's mouth. Splashy M38 and
nearby, powdery NGC 1907 were featured in Ken Hewitt-White's "A Chariot
Full of Clusters" (S&T: Mar. 2008, p. 55).
Off the lip of the Cheshire Cat, right
next to Phi Aurigae, the open cluster

Stock 8 is wrapped in the nebulous
cloak of IC 417. Through my 105-mm
refractor at 47×, they appear as a hazy
patch with several faint stars, the
brightest one shining at 9th magnitude
near the center. This star becomes a
double (Σ707) at 76×, with the 11thmagnitude companion 18″ southeast of

+36°

M38

AURIGA
Cheshire
Cat

1907

IC 405
Stock 8

f

1931

Mel 31

Star magnitudes

consists of an 8.9-magnitude primary
with a 9.5-magnitude secondary to its
southwest.
Suspecting a small brighter spot in
the nebula about one-third of the way
from the golden star to the 10th-magnitude star at the center of the cluster, I
zoomed in on the area with higher powers. They gave a much better view, and
I could easily see a patch of enhanced
brightness. A faint star rests inside and
a dimmer one nuzzles the southern
edge. This bright region marks the head
of Simeis 130, one of IC 410's cometary
nebulae. Nicknamed the Tadpoles, they
are sites of denser gas and dust being
eroded by stellar winds and radiation
from the cluster. I didn't notice the
head of the other Tadpole, Simeis 129,
located 4′ northwest, nor did I see the
Tadpoles' tails trailing away from the
cluster. Can you?
About ¾° northwest of the Minnow, we ﬁnd the eruptive variable AE
Aurigae, a blue-white star that ﬂuctuates irregularly between magnitude 5.4
and 6.1. This runaway star was ejected
from the Orion star-forming complex
approximately 2.5 million years ago. It's
thought that a close encounter between
two binary systems led to some star
swapping that resulted in the eccentric
binary Iota Orionis and two high-speed
escapees, AE Aurigae and Mu Columbae.
AE Aurigae now serves as the chief
source of illumination for the emission/
reﬂection nebula IC 405, which it only
chanced upon in astronomically recent
times. The German astronomer Max
Wolf noted that the nebular material
surrounding AE Aurigae "looks like a
burning body from which several enormous curved ﬂames seem to break out
like gigantic prominences." He thought
this "ﬂaming star" worth study, and
its nebula thus became known as the
Flaming Star Nebula.
With my 105-mm refractor at 17×,
nebulous haze is fairly obvious near AE
Aurigae and the 7.7-magnitude, paleyellow star 8′ to its northwest. If you
have a hydrogen-beta ﬁlter, IC 405 is
one of the relatively rare objects you can
add to its trophy case - but a narrowband ﬁlter can also be of help. In my

4
5
6
7
8
9
10

AE

IC 417
19

Sh 2-237

+34°

IC 410
1893
16

Espin
332
5h 30m

5h 20m

14

5h 10m

sk yandtelescope.com * JANUARY 2 02 0

55
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Sky & Telescope - January 2020

Table of Contents for the Digital Edition of Sky & Telescope - January 2020
