Sky and Telescope - June 2015 - 47

OBSERVING

Northern Hemisphere's Sky

Fred Schaaf welcomes your
comments at fschaaf@aol.com.

Fred Schaaf

The Magical Midnight Hour
Midnight can truly be a magical time - for observing the heavens. That's especially true at the middle
latitudes of the Northern Hemisphere in the month of
June, when days are longest and prolonged evening and
morning twilights reduce night to a minimum. In fact,
if you live as far north as latitude 50°, there's no night at
°
all in June, only twilight from sunset to sunrise. Even
there, however, the sky is darkest at midnight (by which
we mean more like 1 a.m. if you're on daylight-saving
time, of course).
Do you want to observe the deep sky in your telescope
as well as possible? Do you want to see as many stars
as possible with the naked eye? If your answer to either
question is "Yes," and you're located north of the tropics
in June, then midnight is the best time for you.
Midnight as a refuge. Twilight is a beautiful state of
the sky and much astronomy can be done in it. It should
certainly be distinguished from the ugly, glare-blotched
thing called "a light-polluted sky" that so many of us
have to contend with at home these days. But even if
you're very far from city lights, in June you won't see
faint galaxies or nebulae, or a truly star-studded sky,
until "'round midnight."
IDA (the International Dark-Sky Association) continues to declare various places in the world as dark-sky preserves of various sorts. Midnight is the temporal version
of such refuges for all of us.
A foretaste of late summer's glories. For the past
few Junes in this column I've insisted that we shouldn't
move on too quickly to late summer's attractions,
tantalizing as they are. I've said that we should explore
and enjoy the constellations that are highest in the sky
as dusk fades on June days, even if they're mostly rather
dim: Libra, Serpens Caput, Corona Borealis, Hercules.
Despite their overall faintness, these constellations
oﬀer to telescopic observers wonders like the double
star Alpha (α) Librae (Zubenelgenubi), the spectacular
globular clusters M5 (in Serpens Caput) and M13 (in
Hercules), and several amazing variable and double stars
in Corona Borealis, which for naked-eye observers also
oﬀers the 2nd-magnitude star Gemma and the attractive
semi-circle pattern of its main stars.
But after you make these observations, hang in there
(or rather out there) for the full dark of the middle of
night. By then, the sky is in one of its most striking

AKIRA FUJII

Stay up late to see the summer skies at their best.

Cygnus
states, oﬀering a foretaste of the glories we usually
encounter in late summer when they're visible sooner
after nightfall.
What's highest in the middle of June nights?
Blue-white Vega, the queen star of summer, is nearing
the zenith if you live around latitude 40° north. The
entire Summer Triangle of Vega, Deneb, and Altair is
high, with the iconic sights of those stars' constellations well-placed: M57 (the Ring Nebula) and Epsilon (ε)
Lyrae (the Double Double) in Lyra; and Beta (β) Cygni
(the splendidly colorful double star, Albireo), the North
America Nebula, and Veil Nebula in Cygnus. Scorpius
is on or just passing the meridian, and just behind it
glows the central region of our Milky Way galaxy with its
amazingly numerous deep-sky wonders.
What else is visible in the middle of June nights?
This year, Venus and Jupiter have already set but Saturn
is not far past the meridian. Spica is getting low in the
southwest but Arcturus is still high. The Big Dipper's
bowl, in the northwest, is about as high as the Little Dipper's. Cassiopeia is a little lower in the northeast, and
M31 (the Andromeda Galaxy) is a bit to the lower right
of Cassiopeia. The Great Square of Pegasus is rising,
oriented like a huge diamond, just nor th of east. ✦
Sk yandTelescope.com June 2015

http://www.SkyandTelescope.com

Sky and Telescope - June 2015

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