Explanation:
Telescopes around the world are tracking a bright supernova that occurred in a nearby dusty galaxy.
The powerful stellar explosion was first noted earlier this month.
The nearby galaxy is the photogenic
Centaurus A,
visible with binoculars and known for impressive filaments of
light-absorbing dust that cross its center.
Cen A is featured here in a
high-resolution archival
Hubble Space Telescope
image, with an inset image featuring the
supernova taken from the ground only two days after discovery.
Designated
SN2016adj,
the supernova is highlighted with crosshairs in the inset, appearing just to the left of a bright foreground star in our
Milky Way Galaxy.
This supernova is currently thought to be of
Type IIb, a
stellar-core-collapse supernova,
and is of high interest because it occurred
so nearby
and because it is being seen through a known dust filament.
Current and future observations of
this supernova
may give us new clues about the fates of massive stars and how some
elements found on our Earth were formed.
Explanation:
What's lighting up the Cigar Galaxy?
M82, as this
irregular galaxy is also known, was stirred up by a
recent pass near large
spiral galaxy
M81.
This doesn't fully explain the source of the red-glowing outwardly
expanding gas, however.
Evidence indicates that this gas is being
driven out by the combined emerging
particle winds of many stars, together creating a galactic
superwind.
The featured photographic mosaic highlights a specific color of
red light strongly emitted by ionized
hydrogen gas, showing detailed filaments of this gas.
The filaments extend for over 10,000
light years.
The 12-million light-year distant
Cigar Galaxy is the
brightest galaxy in the sky in infrared light, and can be seen in visible light with a small
telescopetowards the constellation of the Great Bear
(Ursa Major).
Explanation:
Want to take a relaxing
interstellar
vacation?
Consider visiting
Kepler-16b,
a world in a binary star system.
In fact Kepler-16b is the first discovered
circumbinary planet.
It was detected in a wide 229 day orbit around a close pair of cool,
low-mass stars some 200 light-years away.
The parent stars eclipse one another in their orbits, observed as
a periodic dimming of starlight.
But Kepler-16b itself was
discovered by following the additional very slight dimming
produced during its transits.
Like sci-fi planet Tatooine of Star Wars fame,
two suns would set
over its horizon.
Still, Kepler-16b is probably not a Tatooine-like terrestrial
desert world.
Instead, Kepler-16b is thought to be a cold, uninhabitable
planet with about the mass of Saturn and a gaseous surface ...
so plan to dress accordingly.
Or, choose another
Visions of
the Future vacation destination.
Explanation:
Massive star IRS 4 is beginning to spread its wings.
Born only about 100,000 years ago,
material streaming out from this
newborn star has formed the nebula dubbed Sharpless 2-106 Nebula (S106),
featured here.
A large disk of
dust and gas orbiting
Infrared Source 4 (IRS 4), visible in brown near the image center,
gives the nebula an hourglass or
butterfly shape.
S106 gas near IRS 4 acts as an
emission nebula
as it emits light after being
ionized, while
dust
far from
IRS 4 reflects light from the central star and so acts as a
reflection nebula.
Detailed inspection of a recent
infrared image of S106
reveal hundreds of low-mass
brown dwarf stars lurking in
the
nebula's gas.
S106 spans about 2 light-years and lies about 2000 light-years away toward the
constellation of
the Swan (Cygnus).
Explanation:
What caused this unusual light rock formation on Mars?
Intrigued by the possibility that they could be salt deposits left over as an ancient
lakebed dried-up,
detailed studies of these fingers now
indicate a more mundane possibility: volcanic ash.
Studying the
exact color of the formation indicated the possible
volcanic origin.
The light material
appears to have
eroded away from surrounding area,
indicating a very low-density substance.
The stark contrast between the rocks and the surrounding
sand is compounded by the
unusual darkness of the sand.
The featured picture was taken with the
Thermal Emission Imaging System on the
Mars Odyssey, the longest serving
spacecraft currently orbiting
Mars.
The image spans about 10 kilometers inside a
larger crater.
Explanation: Tracks lead to a small robot perched
near the top of this bright little planet.
Of course, the planet is really the Moon.
The robot is the desk-sized Yutu rover, leaving its
looming Chang'e 3 lander after a
after a mid-December 2013 touch down in
the northern Mare Imbrium.
The little planet projection is a digitally warped and stitched
mosaic of images from the
lander's terrain camera
covering 360 by 180 degrees.
Ultimately traveling over 100 meters, Yutu came to a halt in January 2014.
The lander's instruments
are still working though, after more than two years on the
lunar surface.
Meanwhile, an interactive panoramic version of this little planet
is available here.
Explanation:
Just press play to watch two black holes merge.
Inspired by the
first
direct detection of gravitational waves by LIGO,
this
simulation video plays in slow motion but
would take about one third of a second if run in real time.
Set on a cosmic stage the black holes are posed in front of stars, gas,
and dust.
Their extreme gravity lenses the light
from behind them into
Einstein rings
as they spiral closer and finally merge into one.
The otherwise invisible gravitational waves generated
as the massive objects rapidly coalesce cause the visible image
to ripple and slosh both inside and outside the
Einstein rings even after the black holes have merged.
Dubbed GW150914, the gravitational waves
detected by LIGO are
consistent with the merger of 36 and 29 solar mass
black holes at a distance of 1.3 billion light-years.
The final, single black hole has 62 times the mass of the Sun,
with the remaining 3 solar masses converted into energy in
gravitational
waves.
Explanation:
Large galaxies grow by eating small ones.
Even our own galaxy practices galactic
cannibalism, absorbing small galaxies that get too close and
are captured by
the Milky Way's gravity.
In fact, the practice is common in the universe and
illustrated by this striking pair of interacting galaxies
from the banks of the southern constellation
Eridanus,
The River.
Located over 50 million light years away,
the large, distorted spiral NGC 1532 is seen locked in a
gravitational
struggle with dwarf galaxy NGC 1531 (right of center),
a struggle the smaller galaxy will
eventually lose.
Seen edge-on, spiral NGC 1532 spans about 100,000 light-years.
Nicely detailed
in this sharp image, the
NGC 1532/1531 pair is thought to be similar
to the well-studied system of face-on spiral and small companion
known as M51.
The Rise and Fall of Supernova 2015F Video Credit & Copyright:
Changsu Choi & Myungshin Im
(Seoul National University)
Explanation:
Sit back and watch a star explode.
The actual supernova occurred back when
dinosaurs roamed the Earth,
but images of the spectacular event began arriving last year.
Supernova 2015F was discovered in nearby spiral galaxy
NGC 2442 by
Berto Monard
in 2015 March and was unusually bright -- enough to be seen with only a small telescope.
The pattern of brightness variation indicated a
Type Ia supernova --
a type of stellar explosion that results when an Earth-size
white dwarf
gains so much mass that its core crosses the threshold of
nuclear fusion,
possibly caused by a lower mass
white-dwarf companion spiraling into it.
Finding and tracking Type Ia
supernovae are particularly important because their intrinsic brightness can be calibrated,
making their
apparent brightness
a good measure of their distance -- and hence useful toward calibrating the
distance scale of the
entire universe.
The featured video tracked the
stellar disruption from before explosion images arrived, as it brightened,
and for several months as the
fission-powered supernova glow faded.
The remnants of
SN2015F are now too dim to see without a large telescope.
Just yesterday, however, the night sky lit up
once again, this time with an
even brighter supernova in an even closer galaxy:
Centaurus A.
