Astronomy Picture of the Day |
APOD: 2017 September 29 - Puppis A Supernova Remnant
Explanation:
Driven
by the explosion of a massive star,
supernova remnant Puppis A is blasting into the
surrounding interstellar medium about 7,000 light-years away.
At that distance,
this
colorful telescopic field based on broadband and narrowband
optical image data is about 60 light-years across.
As the supernova remnant (upper right) expands into its
clumpy, non-uniform surroundings, shocked filaments
of oxygen atoms glow in green-blue hues.
Hydrogen and nitrogen are in red.
Light from the initial supernova itself, triggered by
the collapse of the massive
star's core, would have reached
Earth about 3,700 years ago.
The Puppis A remnant is actually seen through
outlying emission from the closer but more ancient
Vela supernova remnant, near the
crowded plane of our Milky Way galaxy.
Still glowing across the electromagnetic spectrum
Puppis A remains one of the brightest sources
in the X-ray sky.
APOD: 2015 August 28 - Puppis A Supernova Remnant
Explanation:
Driven
by the explosion of a massive star,
supernova remnant Puppis A is blasting into the
surrounding interstellar medium about 7,000 light-years away.
At that distance,
this
colorful telescopic field based on broadband and narrowband
optical image data is about 60 light-years across.
As the supernova remnant expands into its
clumpy, non-uniform surroundings, shocked filaments
of oxygen atoms glow in green-blue hues.
Hydrogen and nitrogen are in red.
Light from the initial supernova itself, triggered by
the collapse of the massive
star's core, would have reached
Earth about 3,700 years ago.
The Puppis A remnant is actually seen through
outlying emission from the closer but more ancient
Vela supernova remnant, near the
crowded plane of our Milky Way galaxy.
Still glowing across the electromagnetic spectrum
Puppis A remains one of the brightest sources
in the X-ray sky.
APOD: 2013 May 15 - Kepler's Supernova Remnant in X-Rays
Explanation:
What caused this mess?
Some type of star exploded to create the unusually shaped nebula known as
Kepler's supernova remnant,
but which type?
Light from the
stellar explosion
that created this energized cosmic cloud was first seen on planet
Earth in October 1604, a mere
four hundred years
ago.
The supernova produced a bright new star
in early 17th century skies within the constellation Ophiuchus.
It was studied by astronomer
Johannes Kepler
and his contemporaries, without the benefit of a telescope, as they
searched for an
explanation
of the heavenly apparition.
Armed with a modern understanding of
stellar evolution, early 21st century
astronomers continue to explore the expanding debris cloud, but can now use
orbiting space telescopes to survey Kepler's supernova remnant (SNR)
across the spectrum.
Recent
X-ray data and
images
of Kepler's supernova remnant taken by the orbiting
Chandra X-ray Observatory has shown relative elemental abundances typical of a
Type Ia supernova, and further indicated that the progenitor was a
white dwarf star that exploded
when it accreted too much material from a companion
Red Giant star and went over
Chandrasekhar's limit.
About 13,000 light years away, Kepler's supernova
represents the most recent stellar explosion seen to
occur within
our Milky Way galaxy.
APOD: 2012 January 12 - The Case of the Missing Supernova Companion
Explanation:
Where's the other star?
At the center of this supernova remnant should be the companion star to the star that blew up.
Identifying this star is important for understanding just how
Type Ia supernova detonate, which in turn could lead to a better understanding of why the brightness of
such explosions are so predictable, which in turn is key to calibrating the entire
nature of our universe.
The trouble is that even a careful inspection of the center of
SNR 0509-67.5 has not found any star at all.
This indicates that the companion is intrinsically very faint -- much more faint that many types of
bright giant stars that had been previous candidates.
In fact, the implication is that the
companion star might have to be a faint
white dwarf,
similar to -- but less massive than -- the star that detonated.
SNR 0509-67.5 is shown above in both visible light,
shining in red as imaged by the Hubble Space Telescope, and
X-ray light, shown in false-color green as imaged by the
Chandra X-ray Observatory.
Putting your cursor over the picture will highlight the central required
location for the missing companion star.
APOD: 2010 March 18 - Fermi Catalogs the Gamma ray Sky
Explanation:
What shines
in the gamma-ray sky?
The most complete answer yet to that question is offered by the
Fermi Gamma-ray Space Telescope's
first all-sky catalog.
Fermi's sources
of cosmic
gamma-rays feature nature's most energetic
particle
accelerators,
ultimately producing 100 MeV to 100 GeV photons, photons with
more than 50 million to 50 billion times the
energy
of visible light.
Distilled from 11 months of sky survey data using Fermi's Large Area
Telescope (LAT), the 1,451 cataloged sources include energetic
star burst galaxies
and active galactic nuclei (AGN)
far beyond the Milky Way.
But within our own galaxy are
many pulsars (PSR)
and
pulsar wind nebulae (PWN),
supernova remnants (SNR),
x-ray binary stars (HXB) and
micro-quasars
(MQO).
Fermi's all sky map is shown centered on the Milky Way
with the diffuse gamma-ray emission from the Galactic plane
running horizontally through the frame.
To locate the cataloged gamma-ray sources,
just slide your cursor over the map.
For now, 630 of the
sources cataloged at gamma-ray energies
remain otherwise unidentified, not associated with sources detected
at lower energies.
APOD: 2009 June 12 - SNR 0104: An Unusual Suspect
Explanation:
SNR 0104 is a supernova remnant with an unusual shape.
Found 190,000 light-years away in our neighboring galaxy
the Small Magellanic Cloud,
SNR 0104 is suspected of being the expanding debris cloud from a
Type 1a
supernova - the catastrophic thermonuclear explosion of
a white dwarf star.
For example, like Type 1a supernova remnants within
our galaxy, investigations show that it contains
large amounts of iron.
But unlike other Type 1a remnants, including the well-studied
Tycho,
Kepler, and
SN 1006, SNR 0104 is
definitely not spherical.
In fact, the remnant's shape suggests this supernova explosion
was very asymmetric and produced strong jets.
This intriguing
composite image combines
Chandra Observatory
x-ray data of the remnant, shown in purple hues, with
Spitzer Space Telescope infrared
data covering the wider region, mapped to red and green colors.
It indicates that the supernova explosion
took place in the complicated and dense environment of a
star-forming region.
So, an alternative explanation is that the expanding debris cloud
is sweeping up clumpy interstellar material, accounting
for the odd shape.
The broad, multiwavelength
view spans about 1,800 light-years at the
estimated distance of SNR 0104.
APOD: 2007 January 16 - Keplers Supernova Remnant in X Rays
Explanation:
What caused this mess?
Some type of star exploded to create the unusually shaped nebula known as
Kepler's supernova remnant,
but which type?
Light from the stellar explosion that
created this energized cosmic cloud was first seen on planet
Earth in October 1604, a mere
four hundred years
ago.
The supernova produced a bright
new star
in early 17th century skies within the constellation
Ophiuchus.
It was studied by astronomer
Johannes Kepler
and his contemporaries, with out the benefit of a telescope, as they
searched for an explanation of the heavenly apparition.
Armed with a
modern
understanding of stellar evolution, early 21st century
astronomers continue to explore the expanding debris cloud, but can now use
orbiting space telescopes to survey Kepler's supernova remnant (SNR)
across the spectrum.
Recent X-ray data and
images
of Kepler's supernova remnant taken by the orbiting
Chandra X-ray Observatory has shown relative elemental abundances more typical of a
Type Ia supernova, indicating that the progenitor was a
white dwarf star that exploded
when it accreted too much material and went over
Chandrasekhar's limit.
About 13,000 light years away, Kepler's supernova
represents the most recent stellar explosion seen to
occur within
our Milky Way galaxy.
APOD: 2005 August 13 - SNR 0103 72.6: Oxygen Supply
Explanation:
A supernova explosion,
a massive star's inevitable and
spectacular demise,
blasts back into space debris enriched in the
heavy elements
forged in its
stellar core.
Incorporated into future stars and planets, these are the
elements ultimately necessary for life.
Seen here in
a false-color x-ray image, supernova remnant
SNR 0103-72.6 is revealed to be just such an expanding debris
cloud in neighboring galaxy, the
Small Magellanic Cloud.
Judging from the measured size of the expanding outer ring of
shock-heated gas, about 150 light-years, light from
the original supernova explosion would have first reached
Earth about 10,000 years ago.
Hundreds of supernova remnants
have been identified as
much sought after astronomical laboratories for studying the cycle of
element synthesis
and enrichment, but the
x-ray data also show
that the hot gas at the center of this
particular supernova remnant is exceptionally rich
in neon and oxygen.
APOD: 2004 October 8 - Kepler's SNR from Chandra, Hubble, Spitzer
Explanation:
Light from the stellar explosion that
created this energized cosmic cloud was first seen on planet
Earth in October 1604, a mere
four hundred years
ago.
The supernova produced a bright
new star
in early 17th century skies within the constellation
Ophiuchus.
It was studied by astronomer
Johannes Kepler
and his contemporaries, with out the benefit of a telescope, as they
searched for an explanation of the heavenly apparition.
Armed with a
modern
understanding of stellar evolution,
early 21st century
astronomers continue to explore the
expanding debris cloud, but can now use
orbiting space telescopes to
survey Kepler's supernova remnant (SNR)
across the spectrum.
In this tantalizing composite image,
x-rays,
visible light, and
infrared
radiation recorded by NASA's astrophysical
observatories - the
Chandra X-Ray Observatory,
Hubble and
Spitzer
space telescopes - are combined to give a more comprehensive
view of the still enigmatic supernova remnant.
About 13,000 light years away,
Kepler's supernova
represents the most recent stellar explosion seen to
occur within
our Milky Way galaxy.
APOD: 2004 May 22 - X-Rays From Tycho's Supernova Remnant
Explanation:
In 1572,
Danish
astronomer
Tycho Brahe
recorded the sudden appearance of
a bright new star in the constellation Cassiopeia.
The
new star faded from view over a period of months and is
believed to have been a supernova, one of the last stellar explosions
seen in our Milky Way galaxy.
Now known
as Tycho's Supernova Remnant, the expanding debris cloud is
shown in this detailed
false-color x-ray image
from the orbiting Chandra Observatory.
Represented in blue, the highest energy x-rays come from shocked regions
along the outer edges of the supernova remnant, corresponding to gas at
temperatures of 20 million degrees Celsius.
X-rays
from cooler gas (only 10 million degrees or so!) dominate the
remnant's interior.
Unlike some
other supernova remnants,
no hot central
point source
can be found, supporting the theory
that the origin of this stellar explosion
was a runaway nuclear detonation that ultimately
destroyed a white dwarf star.
At a distance of about 7,500 light-years,
Tycho's Supernova Remnant
appears to be nearly 20 light-years across.
This x-ray picture's field of view slightly cuts off the
bottom of the generally spherical cloud.
APOD: 2004 January 1 - Structure in N63A
Explanation:
Shells and arcs abound in this false-color,
multiwavelength view of
supernova
remnant N63A, the debris of
a massive stellar explosion.
The x-ray emission
(blue), is from gas heated to 10 million degrees C as knots of
fast moving material from
the
cosmic blast sweep up
surrounding interstellar matter.
Radio (red) and optical emission (green)
are brighter near the central regions where the x-rays
seem to be absorbed by denser, cooler material on the side of
the expanding debris cloud facing the Earth.
Located in the neighboring galaxy known as the
Large Magellanic Cloud,
the apparent
age
of this supernova remnant is between 2,000 and 5,000 years,
its extended glow spanning about 60 light-years.
The intriguing image is a
composite of x-ray data from the orbiting
Chandra
Observatory, optical data from the
Hubble Space Telescope, and
radio from the
Australia Telescope Compact Array.
APOD: 2003 May 28 - SNR 0103-72.6: Oxygen Supply
Explanation:
A supernova explosion,
a massive star's inevitable and
spectacular demise,
blasts back into space debris enriched in the heavy elements
forged
in its
stellar core.
Incorporated into future stars and planets, these are the
elements ultimately necessary for life.
Seen here in
a false-color x-ray image, supernova remnant
SNR 0103-72.6 is revealed to be just such an expanding debris
cloud in neighboring galaxy, the
Small
Magellanic Cloud.
Judging from the measured size of the expanding outer ring of
shock-heated gas, about 150 light-years, light from
the original supernova explosion would have first reached
Earth about 10,000 years ago.
Hundreds of supernova remnants
have been identified as
much sought after astronomical laboratories for studying the
cycle of
element synthesis
and enrichment, but the
x-ray data also show
that the hot gas at the center of this
particular supernova remnant is exceptionally rich
in neon and oxygen.
APOD: 2002 September 12 - X-Rays From Tycho's Supernova Remnant
Explanation:
In 1572,
Danish
astronomer
Tycho Brahe
recorded the sudden appearance of
a bright new star in the constellation Cassiopeia.
The
new star faded from view over a period of months and is
believed to have been a supernova, one of the last
stellar explosions seen
in our Milky Way galaxy.
Now known
as Tycho's Supernova Remnant, the expanding debris cloud is
shown in this detailed
false-color x-ray image
from the orbiting Chandra Observatory.
Represented in blue, the highest energy x-rays come from shocked regions
along the outer edges of the supernova remnant, corresponding to gas at
temperatures of 20 million degrees Celsius.
X-rays
from cooler gas (only 10 million degrees or so!) dominate the
remnant's interior.
Unlike some
other supernova remnants,
no hot central
point source
can be found, supporting the theory
that the origin of this
stellar explosion
was a runaway nuclear detonation that ultimately
destroyed a white dwarf star.
At a distance of about 7,500 light-years,
Tycho's Supernova Remnant
appears to be nearly 20 light-years across.
This x-ray picture's field of view slightly cuts off the
bottom of the generally spherical cloud.
APOD: February 11, 1998 - Ultra Fast Pulsar
Explanation:
Pulsars are rotating
neutron stars, born in the violent
crucibles of supernova explosions.
Like cosmic lighthouses, beams of radiation from surface hotspots sweep
past our viewpoint creating pulses which reveal the rotation rates
of these incredibly dense stellar corpses.
The most famous pulsar of all is found in the nearby supernova
remnant, the Crab Nebula.
The Crab's young pulsar is fast.
Rotating at 33 times a second,
its radiation energizes the surrounding
gaseous stellar debris.
But using
archival observations from orbiting X-ray telescopes,
astronomers have recently identified another "Crab-like" pulsar
that is even faster.
Located in the Large Magellanic Cloud (LMC),
X-ray pulses from this newly discovered pulsar,
in the supernova remnant N157B,
indicate an even faster rotation rate - 62 times a second -
making it
the fastest known pulsar associated with a supernova remnant.
This contoured, false color X-ray image of
a portion of the LMC
shows the location of N157B along with
the core of the nearby
hot star cluster R136,
and the site of another Crab-like pulsar in SNR 0540-69.3
(rotating a mere 20 times a second).
The image is about 1,500 light-years across.