Central Cygnus Skyscape
Image Credit & Copyright:
Paul C. Swift
Explanation:
In cosmic brush strokes
of glowing
hydrogen gas, this beautiful
skyscape unfolds across the plane of our
Milky Way Galaxy and
the center of the northern constellation
Cygnus the Swan.
The
featured image spans about six degrees.
Bright supergiant star
Gamma Cygni
(Sadr) to the upper left of the image
center lies in the foreground of the complex gas and dust clouds
and
crowded star fields.
Left of Gamma Cygni,
shaped like two luminous wings divided by
a long dark dust lane is IC 1318, whose popular name is understandably the
Butterfly Nebula.
The more compact, bright nebula at the lower right is NGC 6888,
the
Crescent Nebula.
Some distance estimates for Gamma Cygni place it at
around 1,800
light-years while estimates for IC 1318 and NGC 6888 range
from 2,000 to 5,000 light-years.
Announcing Comet Catalina
Image Credit & Copyright:
Ian Sharp
Explanation:
Will Comet Catalina become visible to the unaided eye?
Given the unpredictability of comets, no one can say for sure, but it seems like a good bet.
The comet was discovered in 2013 by observations of the
Catalina Sky Survey.
Since then,
Comet C/2013 US10 (Catalina)
has steadily brightened and is currently brighter than 8th
magnitude, making it visible with binoculars and
long-duration camera images.
As
the comet
further approaches the inner Solar System it will surely
continue to intensify,
possibly becoming a naked eye object sometime in October and
peaking sometime in late November.
The
comet
will reside primarily in the skies of the southern hemisphere until
mid-December, at which time its highly inclined orbit will bring it
quickly into northern skies.
Featured above,
Comet Catalina was imaged last week sporting a
green coma and
two growing tails.
Andromeda Rising over the Alps
Image Credit & Copyright:
Matteo Dunchi
Explanation:
Have you ever seen the Andromeda galaxy?
Although
M31
appears as a faint and fuzzy blob to the unaided eye, the light you see will be over two million years old,
making it likely the oldest light you ever will
see directly.
Now rising near a few hours after sunset from mid-latitude northern locations,
Andromeda is
rising earlier
each night and will be visible to northerners all night long starting in September.
The
featured image captured
Andromeda rising above the
Italian
Alps last month.
As cool as it may be to see this
neighboring galaxy to our
Milky Way
with your own eyes, long duration camera exposures can pick up many
faint and
breathtaking details.
Recent data indicates that our Milky Way Galaxy
will collide and coalesce
with the slightly larger Andromeda galaxy in a few billion years.
M1: The Crab Nebula from Hubble
Image Credit:
NASA,
ESA,
J. Hester, A. Loll (ASU)
Explanation:
This is the mess that is left when a star explodes.
The
Crab Nebula, the result of a
supernova seen in
1054 AD, is filled with
mysterious filaments.
The
filaments are not only
tremendously complex, but appear to have
less mass than expelled in the original supernova and a
higher speed than expected from a free explosion.
The
featured image,
taken by the
Hubble Space Telescope,
is presented in three colors chosen for
scientific interest.
The
Crab Nebula spans about 10
light-years.
In
the nebula's very center lies a
pulsar: a
neutron star as massive as the
Sun
but with only the size of a
small town.
The
Crab Pulsar rotates about 30 times each second.
Perihelion Approaches
Image
Credit:
ESA /
Rosetta / MPS for
OSIRIS Team;
MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Explanation:
This dramatic outburst from the nucleus of
Comet 67P/Churyumov-Gerasimenko
occured on August 12, just hours before perihelion,
its closest approach to the Sun.
Completing an orbit of the Sun once every 6.45 years,
perihelion distance for this periodic comet is about 1.3
astronomical units (AU),
still outside the orbit of planet Earth (at 1 AU).
The stark image of the
4 kilometer wide,
double-lobed nucleus
in bright sunlight and dark shadows
was taken by the Rosetta spacecraft's science camera
about 325 kilometers away.
Too close to see the
comet's growing tail,
Rosetta maintains its
ringside seat to watch
the nucleus warm and become more active in coming weeks, as primordial ices
sublimating
from the surface produce jets of gas and dust.
Of course, dust from the nucleus of periodic comet Swift-Tuttle,
whose last perihelion passage was in 1992 at a distance of 0.96 AU,
fell to Earth just this week.
Comet Dust over Enchanted Rock
Image Credit &
Copyright:
Jared Tennant
Explanation:
Dusty debris from
periodic Comet Swift-Tuttle
was swept up by planet Earth this week.
Vaporized by their passage through the dense atmosphere
at 59 kilometers per second,
the tiny grains produced a stream of
Perseid
meteors.
A bright, colorful Perseid meteor flash was captured during
this 20 second exposure.
It made its ephemeral appearance after midnight on August 12,
in the
moonless skies over the
broad
granite dome of
Enchanted Rock State Natural Area, central Texas, USA.
Below the Perseid meteor, trees stand in silhouette against
scattered lights along the horizon and the faint Milky Way, itself
cut by dark clouds of interstellar dust.
Moonless Meteors and the Milky Way
Image Credit &
Copyright:
Petr Horálek
Explanation:
Have you watched the
Perseid meteor shower?
Though the annual shower's predicted peak was last night,
meteor activity should continue tonight (August 13/14),
best enjoyed by just looking up in clear, dark skies
after midnight.
Of course,
this year's Perseid shower has the advantage
of being active near the August 14 New Moon.
Since the nearly New Moon doesn't rise before the
morning twilight many fainter meteors are easier to spot until then,
with no interference from bright moonlight.
The Perseid meteor shower last occurred near a New Moon
in 2013.
That's when the exposures used to construct
this image were made, under dark, moonless skies
from Hvar Island off the coast of Croatia.
The widefield
composite includes 67
meteors streaming from
the heroic constellation Perseus, the shower's radiant,
captured during 2013 August 8-14 against
a background of faint
zodiacal light and the Milky Way.
The next moonless Perseid meteor shower will be in August 2018.
Milky Way and Exploding Meteor
Image Credit & Copyright:
André van der Hoeven
Explanation:
Tonight the
Perseid Meteor Shower reaches its maximum.
Grains of icy rock will streak across the sky as they evaporate during entry into Earth's atmosphere.
These grains were shed from
Comet Swift-Tuttle.
The
Perseids result from the annual crossing of the Earth through
Comet Swift-Tuttle's orbit, and are
typically the most active
meteor shower of the year.
Although it is hard to predict the level of activity in any meteor shower, in a clear dark sky an observer might see a
meteor a minute.
This year's
Perseids occur just before a
new Moon
and so the relatively dark sky should make even faint meteors visible.
Meteor showers in general are best be seen from a
relaxing position, away from lights.
Featured here
is a meteor caught
exploding two weeks ago above
Austria
next to the central band of our
Milky Way Galaxy.
A Blue Moon Halo over Antarctica
Image Credit & Copyright:
LI Hang
Explanation:
Have you ever seen a halo around the Moon?
Such
22 degree rings around the Moon -- caused by
ice crystals
falling in the
Earth's atmosphere -- are
somewhat rare.
OK, but have you ever seen a blue moon?
Given the modern definition of
blue moon -- the second full moon occurring in a calendar month -- these are also rare.
What is featured above might therefore be considered doubly rare -- a
halo surrounding a
blue moon.
The featured image was taken late last month near
Zhongshan Station
in Antarctica.
Visible in the foreground are a power generating house and a
snowmobile.
What might seem to be stars in the background are actually illuminated snowflakes near the camera.
A Sagittarius Triplet
Image Credit & Copyright:
Christian vd Berge
(DSLR Astrophotograhy)
Explanation:
These three bright nebulae are often
featured in telescopic tours of the constellation
Sagittarius and the crowded starfields of
the
central Milky Way.
In fact, 18th century cosmic tourist
Charles Messier
cataloged two of them;
M8, the large nebula left of center,
and colorful
M20 on the right.
The third,
NGC 6559, is above M8,
separated from the larger nebula by a dark dust lane.
All three are stellar nurseries about
five thousand light-years or so distant.
The expansive M8, over a hundred light-years across,
is also known as the
Lagoon Nebula.
M20's popular moniker is
the Trifid.
Glowing hydrogen gas creates the dominant red color of the
emission nebulae, with contrasting blue hues, most striking in the
Trifid, due to dust
reflected starlight.
The colorful skyscape
recorded with telescope and digital camera
also includes one of Messier's open star clusters,
M21,
just above the Trifid.
HCG 87: A Small Group of Galaxies
Image Credit:
GMOS-S Commissioning Team,
Gemini Observatory
Explanation:
Sometimes galaxies form groups.
For example, our own
Milky Way Galaxy is part of the
Local Group of Galaxies.
Small, compact groups, like
Hickson Compact Group 87
(
HCG 87)
shown above,
are interesting partly because they slowly self-destruct.
Indeed, the galaxies of
HCG
87 are gravitationally stretching each other during their 100-million year
orbits around a common center.
The
pulling creates colliding gas that causes bright bursts of
star formation and feeds matter into their
active galaxy centers.
HCG 87
is composed of a large
edge-on
spiral galaxy visible near the image center, an
elliptical galaxy
visible to its right, and a
spiral galaxy visible near the top.
The small spiral near the center might be far in the distance.
Several stars from
our Galaxy are also visible in the foreground.
Studying groups like HCG 87 allows insight into how all
galaxies form and evolve.
Source -
NASA
