Sky and Telescope - November 2017 - 46

NOVEMBER 2017 OBSERVING
Sun, Moon & Planets by Fred Schaaf

At the Edge of the Day
All the bright planets congregate at either dusk or dawn this month.

F

or yet another month, all ﬁve bright
planets congregate near dusk or
dawn. They're not always easy to see,
but they engage in some remarkable
conjunctions, particularly when a few
bright stars join the scene.
Mars is the most steadily present this
month, rising a few hours before morning twilight. Then dawn brings us Venus
(and Spica) in the ﬁrst days of November. A week later bright Jupiter returns
low in the east, where it passes an even
brighter Venus in a low but close and
spectacular conjunction.
In the second half of November,
Mercury comes into view at dusk, very
low in the southwest, for a rather poor
apparition for observers at mid-northern latitudes. Departing Saturn follows
Mercury down to set, and then there's
a long wait before any bright planet
enters the sky.

Dawn, Nov 4

DU S K
Mercury might be ﬁrst glimpsed with
binoculars around November 17th, very
low in the southwest 20 minutes after
sunset. How early in the month can you
spot it?
Mercury is at greatest elongation,
22° east of the Sun, on November 23rd,
and in the last week of the month,
moves a little higher in evening twilight. It's a bright magnitude -0.4 all
the while, but in November's ﬁnal days
it begins to fade while still only 5° or 6°
high 30 minutes after sunset. It closes
the month at magnitude -0.2.
Saturn, even fainter at magnitude
+0.5, starts the month moderately well
up in twilight, setting about 2½ hours
after the Sun. By the end of November, the ringed planet drops below the
horizon little more than an hour after
the Sun. Over the course of the month,

Dawn, Nov 11 -12

45 minutes before sunrise

1 hour before sunrise

Saturn sinks lower and lower, edging
toward brighter Mercury. On November
24th, Saturn shines about 5° directly
above Mercury. By the 28th, they're 3°
apart and closing.

EVENING
Neptune reached opposition in September and is now highest - and so
best observed - in early evening. This
7.9-magnitude world remains less than
1° from Lambda (λ) Aquarii.
Uranus was at opposition in October and is now highest in late evening.
At magnitude 5.7, Uranus shines eight
times brighter than Neptune, which
makes it an easier observing target.
But it's hanging out in the dim constellation of Pisces, adding a level of
difﬁculty to your star-hop. Even so,
Uranus is well within reach of handheld
binoculars.
Finder charts for Uranus and Neptune can be found on pages 50-51 of
the October issue.

E A R LY M O R N I N G

a Vir

Sickle

Mars

Moon
Nov 11

10°

LEO

Venus

Regulus

Moon
Nov 12

Spica
Denebola

Looking East-Southeast

46

N O V E M B E R 2 0 17 * S K Y & T E L E S C O P E

Looking Southeast, high in the sky

Mars leads the Sun in November, rising
three to four hours earlier than our star.
As it glides across a section of the long
constellation Virgo, it remains dim and
far away, its orange glow no brighter
than magnitude 1.7.
On the morning of November 4th,
Mars gleams orange just 3° upper right
of the double star Gamma (γ) Virginis
(commonly known as Porrima). By
the 6th, the distance between the two
closes to 2°; they remain close through
the 9th. Look for the 1st-magnitude
star Spica some 15° below this duo and
Venus lower left of Spica before twilight
transitions to sunrise.
Sky and Telescope - November 2017

Table of Contents for the Digital Edition of Sky and Telescope - November 2017
