My first Magazine Sky & Telescope - 03.2019 | Page 45

h
URSA MAJOR
+
LEO MINOR
`
°
o
b in
cular v iew
HD 81440
9
10
38
LYNX
11
_
LEO
CANCER
Binocular Highlight by Mathew Wedel
Fly By N ight
H
WHEN TO
USE THE MAP
Late Jan
Early Feb
Late Feb
Early Mar
Late Mar
Midnight
11 p.m.
10 p.m.
9 p.m.
9 p.m.*
*Daylight-saving time
ere’s something I stumbled upon last spring:
a winged asterism at the western end of Leo
Minor. The anchor star is 10 Leonis Minoris, which
forms an isosceles triangle with Alpha (α) and 38
Lyncis about 3° farther west. I initially sketched the
asterism as a seagull, but on subsequent visits 9
Leonis Minoris and 10 LMi struck me as the yel-
low eyes of a bat. Whatever you call it, this night
fl yer is above the horizon before midnight between
November and July, but it only fl ies right-side up
when the bright stars Pollux and Procyon are cross-
ing the meridian (see chart at left). Hang on to Pollux
and Procyon, we’ll have need of them in a minute.
The “eyes,” 9 and 10 Leonis Minoris, are both
giant stars, larger, cooler, and more yellow-orange
than the Sun. The stars that form the wings are
mostly yellow-white main-sequence stars, with a few
orange giants thrown in. A couple of them make for
interesting comparisons. The star nearest the bird’s
body in the eastern “wing,” 11 Leonis Minoris, is a
G-type main-sequence star very similar to our own
Sun. It gives us a pretty good idea of what the Sun
would look like from 37 light-years away. Pollux, 25°
southwest in Gemini, the Twins, is about the same
distance from Earth, 34 light-years, but as a K-type
orange giant it’s much brighter.
Now have a look at HD 81440, the middle star
in the western “wing.” It’s an F-type yellow-white
main-sequence star. In terms of size and spectral
class it’s a close match with Procyon, which lies 40°
away in Canis Minor, the Little Dog. The difference in
apparent brightness is down to distance: HD 81440
lies 350 light-years away, versus a mere 11 light-
years for Procyon.
¢ MATT WEDEL is gazing into the starry abyss and
having fun cataloging whatever gazes back.
sk yandtele scope.com • M A RCH 2 019
43