Download Astronomy Club of Asheville February 2017 Sky Events

Astronomy Club of Asheville
February 2017 Sky Events
The Planets this Month – page 2
The Gibbous Moon Joins the Hyades – page 5
Conjunction of Jupiter, the Moon and Spica – page 6
Planet Highlights – page 7
Moon Phases in February – page 10
Deep Penumbral Lunar Eclipse – page 11
www.AstroAsheville.org
Astronomy Club of Asheville
February 2017 Sky Events – the Planets
 A dazzlingly brilliant Venus and a much underwhelmed Mars
will closely pair up all month in the south-southwest skies. Find
them both at dusk in the constellation Pisces.
 Glowing at magnitude -4.8, Venus should be easy to locate.
Look to the “Evening Star’s” upper left to spot Mars’ much
fainter orange disk.
 Venus reaches its greatest illuminated extent (maximum
illuminated area in square arcseconds) on February 17th and
also its greatest brilliance of 2017. By late in the month, Venus’
diameter will be almost ten times larger than Mars and will
shine about 250 times brighter!
 Faint Uranus, dimly glowing at 6th magnitude, is still visible in
the southwest as evening twilight ends. This month it
accompanies Venus and Mars in the constellation Pisces.
Astronomy Club of Asheville
February 2017 Sky Events – the Planets
 On February 26th, Mars glides just 0.6° north-northwest of
Uranus. Use telescopic aid at low power or binoculars to catch
both planetary disks in the same field-of-view.
 Neptune is heading toward an early March conjunction (on
the other side of the Sun as seen from Earth) and is therefore
lost in the evening twilight and the Sun’s glare all month.
 Jupiter, at magnitude -2.2, can be found in the constellation
Virgo, rising in the east-southeast by midnight as February
begins and two hours earlier, 10 p.m., by month’s end.
 On February 17th Jupiter reaches aphelion – its farthest point
from the Sun during its orbit – for the first time in 12 years. On
this day, the gas giant will be 5.46 AU, or approximately 508
million miles, from the Sun!
Astronomy Club of Asheville
February 2017 Sky Events – the Planets
 Saturn emerges from the east-southeast horizon about 2 hours
before sunrise on February 1st. As it transitions through the
month from the constellation Ophiuchus into Sagittarius, it will
join one of the richest and most beautiful regions of the Milky
Way. The ringed planet, however, is thousands of light years
closer to the Earth than many of the deep-sky objects seen
behind it!
 Mercury will be found the first three weeks of February, very
low in south-southeast skies about an hour before sunrise
before becoming lost in the Sun’s glare by month’s end.
Binoculars will be helpful to spot this elusive planet, shining
this month at magnitude -1.2, through the glow of dawn.
Astronomy Club of Asheville
February 2017 Sky Events – the Planets
The Gibbous Moon Joins the Hyades
On the evenings of Saturday and
Sunday, February 4–5, the
waxing gibbous moon joins the
Hyades, a large open star cluster
in the constellation Taurus.
The red giant star Aldebaran is 65
light years behind the Moon,
while the Hyades cluster is more
than double this distance, at 153
light years behind the Moon!
Look south, high in the sky near
the meridian, about 90 minutes
after sunset to catch this view.
Image courtesy of Sky & Telescope
Astronomy Club of Asheville
February 2017 Sky Events – the Planets
Dawn Conjunction of the Moon, Jupiter and Spica
On the mornings of Wednesday and
Thursday, February 15 and 16, a
waning gibbous moon shines near
Jupiter and the bright star Spica in the
constellation Virgo.
Our two dimensional view, as seen from
the Earth, belies the fact that Moon is
some 245,000 miles away on these
mornings, while Jupiter is 508 million
miles away and Spica is 261 light years
away!
Look to the southwest, about 6:15 a.m.
EST, to spot this appealing conjunction.
Image courtesy of Sky & Telescope
Astronomy Club of Asheville
February 2017 Planet Highlights
Planet
Avg.
ConstellaDistance tion(s)
from
Earth
Avg.
Avg.
Diameter Magin arc
nitude
seconds
Mercury 1.3
AUs
Sagittarius,
Capricornus
& Aquarius
5.3
-0.7
Venus
0.4
AUs
Pisces
38.5
-4.8
Mars
1.9
AUs
Pisces
4.8
+1.2
Comments
Page 1 of 3
Visible low in
SE dawn skies
until last days
of month
Prominent as
the “Evening
Star” at dusk
this month
Observe early in
the evening in
the W-SW
Astronomy Club of Asheville
February 2017 Planet Highlights
Avg.
Distance
from
Earth
Constellation(s)
Jupiter
4.8
AUs
Saturn
Uranus
Planet
Avg.
Diameter
in arc
seconds
Avg.
Magnitude
Comments
Virgo
40.5
-2.2
Rising in the east
by 10:00 p.m. by
month’s end.
10.5
AUs
Ophiuchus
&
Sagittarius
15.9
+0.5
20.5
AUs
Pisces
3.4
+5.9
Positioned low
in S-SE predawn skies all
month
Observe it early
in the evening
this month
Page 2 of 3
Astronomy Club of Asheville
February 2017 Planet Highlights
Planet
Avg.
ConstellaDistance tion(s)
from
Earth
Neptune 31
AUs
Aquarius
Avg.
Avg.
Diameter Magin arc
nitude
seconds
2.2
+8.0
Comments
Page 3 of 3
Heading
towards
conjunction with
the Sun (other
side of the Sun
as seen from
Earth) on Mar.
1st
Astronomy Club of Asheville
The Moon – February 2017
First Quarter
3rd
11:19 p.m.
Full Moon**
10th
7:33 p.m.
Last Quarter
18th
2:33 p.m.
New Moon
26th
09:58 a.m.
** The “Snow Moon”
Unless otherwise indicated, all times are EST
Astronomy Club of Asheville
February 2017 Highlight
The February 10th Deep Penumbral Lunar Eclipse
On the evening of Friday, February 10th, Asheville will experience a
penumbral lunar eclipse as our full “Snow Moon” passes through
the Earth’s faint outer penumbral shadow.
But because the moon does not travel into the dark-red umbral section
of Earth’s shadow, penumbral lunar eclipses are less than stunning and
are an exercise in subtlety!
The Earth’s umbral and penumbral shadows as projected into space
Not shown to scale
Astronomy Club of Asheville
February 2017 Highlight
The February 10th Deep Penumbral Lunar Eclipse
While the February 10th eclipse is known as a “deep” penumbral
eclipse because 98.8% of the Moon will pass through the faint
penumbral shadow, with clear skies at the height of mid-eclipse expect
to see only a slight darkening of the northern limb of the moon!
Penumbral eclipses
hardly match the
splendor and drama
provided by full or even
partial lunar eclipses,
and therefore the event
could go unnoticed by
most observers!
** To view, look low to the eastern horizon
to locate the rising full moon.
Astronomy Club of Asheville
February 2017 Highlight
The February 10th Deep Penumbral Lunar Eclipse
Although the eclipse begins Monday evening at 5:34 p.m. EST, effects
of the faint penumbral shadow on the moon won’t be visible until
approximately 90 minutes before mid-eclipse. Therefore, timing for
this event in Asheville is as follows (all times EST):
 Penumbra first visible:
 Mid-Eclipse:
 Penumbra last visible:
6:14 p.m.
7:44 p.m.
9:14 p.m.
This subtle event
might whet your
appetite for the next
total lunar eclipse to
come to the eastern
U.S. – in January
2019!
Illustration courtesy of Sky & Telescope
End