Astronomy Picture of the Day |
APOD: 2023 June 2 - Messier 101
Explanation:
Big, beautiful spiral galaxy M101 is one of the last entries in
Charles Messier's
famous catalog, but definitely not
one of the least.
About 170,000 light-years across, this galaxy is enormous, almost
twice the size of our own Milky Way.
M101 was also one of the original
spiral nebulae
observed by Lord Rosse's large 19th century telescope, the
Leviathan
of Parsontown.
Assembled from 51 exposures recorded by the
Hubble Space Telescope
in the 20th and 21st
centuries, with additional data from ground based telescopes,
this mosaic spans about 40,000 light-years across the central region
of M101 in one of the highest definition
spiral galaxy portraits ever released from Hubble.
The sharp image shows stunning features
of the galaxy's face-on disk of stars and dust along with
background galaxies, some visible right through M101 itself.
Also known as the
Pinwheel Galaxy, M101
lies within the boundaries of the northern constellation
Ursa Major, about 25 million light-years away.
APOD: 2023 May 22 – Supernova Discovered in Nearby Spiral Galaxy M101
Explanation:
A nearby star has exploded and humanity's telescopes are turning to monitor it.
The supernova, dubbed
SN 2023ixf, was discovered by Japanese astronomer
Koichi Itagaki
three days ago and subsequently located on automated images from the
Zwicky Transient Facility
two days earlier.
SN 2023ixf occurred in the photogenic
Pinwheel Galaxy M101, which, being only about 21 million light years away, makes it the closest supernova seen in the past five years, the
second closest in the past 10 years, and the
second supernova found
in M101 in the past 15 years.
Rapid follow up observations already indicate that SN 2023ixf is a
Type II supernova, an explosion that occurs after a
massive star runs out of nuclear fuel and collapses.
The featured image shows
home spiral galaxy two days ago with the
supernova
highlighted, while the roll-over image shows the same galaxy a month before.
SN 2023ixf will likely brighten and remain visible to telescopes for months.
Studying such a close and young
Type II supernova may yield
new clues about
massive stars and how they explode.
APOD: 2021 November 27 - Messier 101
Explanation:
Big, beautiful spiral galaxy M101 is one of the last entries in
Charles Messier's
famous catalog, but definitely not
one of the least.
About 170,000 light-years across, this galaxy is enormous, almost
twice the size of our own Milky Way.
M101 was also one of the original
spiral nebulae
observed by Lord Rosse's large 19th century telescope, the
Leviathan
of Parsontown.
Assembled from 51 exposures recorded by the
Hubble Space Telescope
in the 20th and 21st
centuries, with additional data from ground based telescopes,
this mosaic spans about 40,000 light-years across the central region
of M101 in one of the highest definition
spiral galaxy portraits ever released from Hubble.
The sharp image shows stunning features
of the galaxy's face-on disk of stars and dust along with
background galaxies, some visible right through M101 itself.
Also known as the
Pinwheel Galaxy, M101
lies within the boundaries of the northern constellation
Ursa Major, about 25 million light-years away.
APOD: 2019 November 6 - 21st Century M101
Explanation:
One of the last entries in Charles Messier's
famous catalog, big, beautiful spiral galaxy M101 is
definitely not
one of the least.
About 170,000 light-years across,
this galaxy is enormous, almost
twice the size of our own Milky Way Galaxy.
M101 was
also one of the original spiral nebulae
observed with Lord Rosse's large 19th century telescope, the
Leviathan
of Parsonstown.
In contrast, this multiwavelength view
of the large island universe
is a composite of images recorded by space-based telescopes in the
21st century.
Color coded from X-rays to infrared
wavelengths (high to low energies),
the image data was taken from the
Chandra X-ray
Observatory (purple), the
Galaxy Evolution Explorer (blue),
Hubble Space Telescope(yellow), and the
Spitzer Space Telescope(red).
While the X-ray data trace the location of multimillion degree gas
around M101's exploded stars and neutron star and black hole binary
star systems, the lower energy data follow the
stars and dust that define M101's grand spiral arms.
Also known as the
Pinwheel Galaxy,
M101 lies within the boundaries of the northern constellation
Ursa Major, about 25 million light-years
away.
APOD: 2019 March 15 - A View Toward M101
Explanation:
Big, beautiful spiral galaxy M101 is one of the last
entries in Charles
Messier's famous catalog, but definitely not
one
of the least.
About 170,000 light-years across, this galaxy is enormous,
almost twice the size of our own Milky Way galaxy.
M101 was also one of the original
spiral
nebulae observed by Lord Rosse's large
19th
century
telescope, the Leviathan of Parsontown.
M101 shares
this modern telescopic field of view with more distant background
galaxies, foreground stars within the Milky Way, and
a companion
dwarf galaxy
NGC 5474 (lower right).
The colors of the Milky Way
stars can also be
found in the starlight from the large island universe.
Its core is dominated by light from cool yellowish stars.
Along
its grand design spiral arms are the blue colors of hotter, young stars
mixed with obscuring dust lanes and pinkish star forming regions.
Also known as the
Pinwheel Galaxy,
M101 lies within
the boundaries of the northern constellation Ursa Major,
about 23
million light-years away.
Its companion NGC 5474 has likely been distorted by its past gravitational
interactions with the dominant M101.
APOD: 2018 May 4 - The View Toward M101
Explanation:
Big, beautiful spiral galaxy M101 is one of the last
entries in Charles
Messier's famous catalog, but definitely not
one
of the least.
About 170,000 light-years across, this galaxy is enormous,
almost twice the size of our own Milky Way galaxy.
M101 was also one of the original
spiral
nebulae observed by Lord Rosse's large
19th century
telescope, the Leviathan of Parsontown.
M101 shares
this modern telescopic field of view with
spiky foreground stars within the Milky Way and
a companion
dwarf galaxy
NGC 5474 (lower right).
The colors of the Milky Way
stars can also be
found in the starlight from the large island universe.
Its core is dominated by light from cool yellowish stars.
Along
its grand design spiral arms are the blue colors of hotter, young stars mixed
with obscuring dust lanes and pinkish star forming regions.
Also known as the
Pinwheel Galaxy,
M101 lies within
the boundaries of the northern constellation Ursa Major,
about 23
million light-years away.
NGC 5474 has likely been distorted by its past gravitational interactions with
the dominant M101.
APOD: 2017 May 20 - A View Toward M101
Explanation:
Big, beautiful spiral galaxy M101 is one of the last
entries in Charles
Messier's famous catalog, but definitely not
one
of the least.
About 170,000 light-years across, this galaxy is enormous,
almost twice the size of our own Milky Way galaxy.
M101 was also one of the original
spiral
nebulae observed by Lord Rosse's large
19th century
telescope, the Leviathan of Parsontown.
M101 shares this modern telescopic field of view with
spiky foreground stars within the Milky Way, and more
distant background galaxies.
The colors of the Milky Way
stars can also be
found in the starlight from the large island universe.
Its core is dominated by light from cool yellowish stars.
Along
its grand spiral arms are the blue colors of hotter, young stars mixed
with obscuring dust lanes and pinkish star forming regions.
Also known as the
Pinwheel Galaxy,
M101 lies within
the boundaries of the northern constellation Ursa Major,
about 25 million light-years away.
APOD: 2016 January 23 - Big Dipper, Deep Sky
Explanation:
The Big Dipper
is an easy to recognize, well-known asterism in
northern skies, though many see the
Plough
or Wagon.
Famous bright nebulae of the north can also be found along
its familiar lines, highlighted in this carefully
composed scene with telescopic insets framed in the wider-field
skyview.
All from
Messier's
catalog,
M101 and
M51 are cosmic pinwheel and
whirlpool on the left, spiral galaxies far beyond the Milky Way.
To the right, M108,
a distant edge-on spiral galaxy is seen
close to our galaxy's own
owl-faced planetary nebula M97.
Taken
on January 16, the wider-field view seems to include
an extra star along the Dipper's handle, though.
That's Comet Catalina
(C/2013
US10) now sweeping through
northern nights.
APOD: 2016 January 22 - 21st Century M101
Explanation:
One of the last entries in Charles Messier's
famous catalog, big, beautiful spiral galaxy M101 is
definitely not
one of the least.
About 170,000 light-years across,
this galaxy is enormous, almost
twice the size of our own Milky Way Galaxy.
M101 was
also one of the original spiral nebulae
observed with Lord Rosse's large 19th century telescope, the
Leviathan
of Parsontown.
In contrast, this multiwavelength view
of the large island universe
is a composite of images recorded by space-based telescopes in the
21st century.
Color coded from X-rays to infrared
wavelengths (high to low energies),
the image data was taken from the
Chandra X-ray Observatory (purple), the
Galaxy Evolution Explorer ( blue),
Hubble Space Telescope(yellow), and the
Spitzer Space Telescope(red).
While the X-ray data trace the location of multimillion degree gas
around M101's exploded stars and neutron star and black hole binary
star systems, the lower energy data follow the
stars and dust that define M101's grand spiral arms.
Also known as the
Pinwheel Galaxy,
M101 lies within the boundaries of the northern constellation
Ursa Major, about 25 million light-years
away.
(Editor's Note: Original APOD retracted on January 25.)
APOD: 2016 January 21 - The View Toward M101
Explanation:
Sweeping through northern skies, Comet Catalina (C/2013 US10) made its
closest approach on January 17, passing about 6 light-minutes
from our fair planet.
Dust and ion tails clearly separated
in this Earth-based view,
the comet is also posed for a
Messier moment, near the line-of-sight
to M101, grand spiral galaxy in Ursa Major.
A cosmic pinwheel
at the lower left, M101 is nearly twice the size of our own
Milky Way galaxy, but some 270 thousand light-centuries away.
Both galaxy and comet are relatively bright, easy targets for
binocular-equipped skygazers.
But Comet Catalina
is now outbound from the inner
Solar System
and will slowly fade in coming months.
This
telescopic two panel mosaic spans about 5 degrees (10 Full Moons)
on the sky.
APOD: 2015 June 14 - M101: The Pinwheel Galaxy
Explanation:
Why do many galaxies appear as
spirals?
A striking example is
M101,
shown above,
whose relatively close distance of about 27 million
light years allows it to be studied in some detail.
Observational evidence indicates that a
close gravitational interaction with a neighboring galaxy created
waves of high mass and condensed gas which
continue to orbit the galaxy center.
These
waves compress existing gas and cause
star formation.
One result is that
M101, also called the
Pinwheel Galaxy, has several extremely
bright star-forming regions
(called HII regions) spread across its spiral arms.
M101 is so large that its
immense gravity distorts
smaller nearby galaxies.
APOD: 2012 July 13 - 21st Century M101
Explanation:
One of the last entries in Charles Messier's
famous catalog, big, beautiful spiral galaxy M101 is
definitely not
one of the least.
About 170,000 light-years across,
this galaxy is enormous, almost
twice the size of our own Milky Way Galaxy.
M101 was
also one of the original spiral nebulae
observed with Lord Rosse's large 19th century telescope, the
Leviathan
of Parsontown.
In contrast, this multiwavelength view
of the large island universe
is a composite of images recorded by space-based telescopes in the
21st century.
Color coded from X-rays to infrared
wavelengths (high to low energies),
the image data was taken from the
Chandra X-ray Observatory (purple), the
Galaxy Evolution Explorer ( blue),
Hubble Space Telescope(yellow), and the
Spitzer Space Telescope(red).
While the X-ray data trace the location of multimillion degree gas
around M101's exploded stars and neutron star and black hole binary
star systems, the lower energy data follow the
stars and dust that define M101's grand spiral arms.
Also known as the
Pinwheel Galaxy,
M101 lies within the boundaries of the northern constellation
Ursa Major, about 25 million light-years
away.
APOD: 2011 August 26 - A Young Supernova in the Nearby Pinwheel Galaxy
Explanation:
A nearby star has exploded and telescopes all over the world are turning to monitor it.
The supernova, dubbed PTF 11kly, was discovered by computer only two days ago as part of the
Palomar Transient Factory (PTF) sky survey utilizing the wide angle 1.2-meter
Samuel Oschin Telescope in California.
Its rapid recovery makes it one of the supernovas caught most soon after ignition.
PTF 11kly occurred in the
photogenic
Pinwheel
galaxy
(M101), which, being only about 21 million
light years away, makes it one of the closest supernovas seen in decades.
Rapid follow up observations have already given a clear indication that PTF 11kly is a
Type Ia supernova, a type of
white dwarf detonation that usually progresses in such a standard manner than it has helped to calibrate the
expansion history of the entire universe.
Studying such a close and young
Type Ia event, however, may yield new and unique clues.
If early indications are correct,
PTF 11kly should brighten to about visual magnitude 10 in the coming weeks, making it possible to monitor with even moderately sized telescopes.
APOD: 2011 April 15 - Messier 101
Explanation:
Big, beautiful spiral galaxy M101 is one of the last
entries in Charles
Messier's famous catalog, but definitely not
one
of the least.
About 170,000 light-years across, this galaxy is enormous,
almost twice the size of our own Milky Way galaxy.
M101 was also one of the original
spiral
nebulae observed by Lord Rosse's large
19th century
telescope, the Leviathan of Parsontown.
This
mosaic of M101
was assembled from Hubble Legacy Archive data.
Additional ground-based data was included to further define
the telltale reddish emission from atomic hydrogen gas in
this gorgeous galaxy's star forming regions.
The sharp image shows stunning features in the galaxy's
face-on disk of stars and dust along with background galaxies,
some visible right through M101 itself.
Also known as the
Pinwheel Galaxy,
M101 lies within
the boundaries of the northern constellation
Ursa Major,
about 25 million light-years away.
APOD: 2009 December 30 - Spitzer's M101
Explanation:
Big, beautiful spiral galaxy M101 is one of the last
entries in Charles Messier's
famous catalog, but definitely not
one of the least.
About 170,000 light-years across,
this galaxy is enormous, almost
twice the size of our own Milky Way Galaxy.
M101 was also one of the original
spiral
nebulae
observed by Lord Rosse's large 19th century telescope, the
Leviathan
of Parsontown.
Recorded at
infrared wavelengths
by the Spitzer Space telescope, this
21st century view
shows starlight in blue hues while the galaxy's
dust clouds are in red.
Examining the dust features in the outer rim of the
galaxy,
astronomers
have found that organic molecules present throughout
the rest of M101 are lacking.
The organic molecules tracked by Spitzer's instruments are
called polycyclic aromatic hydrocarbons
(PAHs).
Of course, PAHs are common components of dust in the
Milky Way
and on planet Earth are found in soot.
PAHs are likely destroyed near the outer edges of M101 by energetic
radiation in intense star forming regions.
Also known as the
Pinwheel Galaxy,
M101 lies within the boundaries of the northern constellation
Ursa Major, about 25 million light-years
away.
APOD: 2009 April 14 - M101: The Pinwheel Galaxy
Explanation:
Why do many galaxies appear as
spirals?
A striking example is
M101,
shown above,
whose relatively close distance of about 27 million
light years allows it to be studied in some detail.
Recent evidence indicates that a
close gravitational interaction with a neighboring galaxy created
waves of high mass and condensed gas which
continue to orbit the galaxy center.
These
waves compress existing gas and cause star formation.
One result is that
M101, also called the
Pinwheel Galaxy, has several extremely
bright star-forming regions
(called HII regions) spread across its spiral arms.
M101 is so large that its
immense gravity distorts
smaller nearby galaxies.
APOD: 2008 July 25 - Spitzer's M101
Explanation:
Big, beautiful spiral galaxy M101 is one of the last
entries in Charles Messier's
famous catalog, but definitely not
one of the least.
About 170,000 light-years across,
this galaxy is enormous, almost
twice the size of our own Milky Way Galaxy.
M101 was also one of the original
spiral
nebulae
observed by Lord Rosse's large 19th century telescope, the
Leviathan
of Parsontown.
Recorded at
infrared wavelengths
by the Spitzer Space telescope, this
21st century view
shows starlight in blue hues while the galaxy's
dust clouds are in red.
Examining the dust features in the outer rim of the
galaxy,
astronomers
have found that organic molecules present throughout
the rest of M101 are lacking.
The organic molecules tracked by Spitzer's instruments are
called polycyclic aromatic hydrocarbons
(PAHs).
Of course, PAHs are common components of dust in the
Milky Way
and on planet Earth are found in soot.
PAHs are likely destroyed near the outer edges of M101 by energetic
radiation in intense star forming regions.
Also known as the
Pinwheel Galaxy,
M101 lies within the boundaries of the northern constellation
Ursa Major, about 25 million light-years away.
APOD: 2008 May 17 - Logarithmic Spirals
Explanation:
Uncomfortably close
Typhoon Rammasun (right)
and 25 million light-year distant
galaxy M101 don't seem to
have much in common.
For starters, Rammasun was only a thousand kilometers or so
across while M101 (aka the Pinwheel Galaxy)
spans about 170,000 light-years, making them vastly
dissimilar in scale, not to mention the different
physical environments that control their
formation and
development.
But they do look amazingly alike: each with arms exhibiting the
shape of a simple and beautiful mathematical curve known as a
logarithmic
spiral, a spiral whose separation grows in a
geometric
way with increasing distance from the center.
Also known as the
equiangular spiral, growth spiral, and Bernoulli's
spiral or spira mirabilis, this curve's
rich properties have fascinated
mathematicians
since its discovery by 17th century philosopher
Descartes.
Intriguingly, this abstract shape is much more abundant in nature
than suggested by the striking visual comparison above.
For example, logarithmic spirals can also describe
the tracks of subatomic particles
in a bubble chamber,
the arrangement of
sunflower
seeds and, of course,
cauliflower.
APOD: 2006 March 2 - Messier 101
Explanation:
Big, beautiful spiral galaxy M101 is one of the last
entries in Charles
Messier's famous catalog, but
definitely not
one of the least.
About 170,000 light-years across, this galaxy is enormous, almost
twice the size of our own Milky Way galaxy.
M101 was also one of the original
spiral nebulae
observed by Lord Rosse's large 19th century telescope, the
Leviathan
of Parsontown.
Assembled from 51 exposures
recorded by the Hubble Space Telescope in the 20th and 21st
centuries, with additional data from ground based telescopes,
this mosaic of M101
is touted as the largest, most
detailed
spiral galaxy view ever released from Hubble.
The sharp image shows
stunning features along the galaxy's
face-on disk of stars and dust along with background galaxies,
some visible right through M101 itself.
Also known as the
Pinwheel Galaxy,
M101 lies within
the boundaries of the northern constellation
Ursa Major,
about 25 million light-years away.
APOD: 2003 March 10 - M101: The Pinwheel Galaxy
Explanation:
Why do many galaxies appear as
spirals?
A striking example is M101,
shown above, whose relatively close distance of about 22 million light years allow it to be studied in some detail.
Recent evidence indicates that a
close gravitational interaction with a neighboring galaxy created
waves of high mass and condensed gas which
continue to orbit the galaxy center.
These waves compress existing gas and cause star formation.
One result is that
M101, also called the
Pinwheel Galaxy, has several extremely
bright star-forming regions
(called HII regions) spread across its spiral arms.
M101 is so large that its
immense gravity distorts smaller nearby galaxies.
APOD: 2000 June 10 - M101: An Ultraviolet View
Explanation:
This picture of giant spiral galaxy
Messier 101 (M101) was taken by the
Ultraviolet
Imaging Telescope (UIT).
UIT
flew into orbit as part of
the Astro 2 mission
on-board the Space Shuttle Endeavour in March 1995.
The image has been processed
so that the colors (dark purple through white) represent
an increasing intensity of
ultraviolet light.
Pictures of galaxies like this one show mainly
clouds of gas containing newly formed stars many times more massive
than the sun, which glow strongly in the ultraviolet.
In contrast,
visible light pictures of galaxies tend to be dominated by the yellow
and red light of older stars.
Ultraviolet light,
invisible to the human eye, is blocked by
ozone in the atmosphere so ultraviolet pictures of
celestial objects must be taken from space.
M101 is a mere 22 million light-years away in the constellation
Ursa Major.
Its popular moniker is the Pinwheel Galaxy.
APOD: April 20, 1999 - Candidates for a Hypernova
Explanation:
What created these huge explosion remnants?
Speculation has been building recently that
outbursts even more powerful than well-known
supernovae might occur.
Dubbed
hypernovae, these explosions might result
from high-mass stars and liberate perhaps
ten times more energy than conventional
supernovae. A
hypernova was originally postulated to
explain the great amount of energy seemingly liberated in a
gamma-ray burst.
A
search for visible remnants of hypernovae
has now yielded the
above two candidates.
Nearby spiral galaxy
M101, shown on the right,
has two large expanding shells that might have originated from a hypernova. Remnant NGC 5471B on the
upper left and MF83 below were identified
by the unusually high amount of X-ray radiation they emit.
MF83 is also one of the largest
expanding shells ever found.
Research continues into the possible nature and
visibility of hypernovae and the gas shells
they likely leave behind.
APOD: August 5, 1997 - M101: The Pinwheel Galaxy
Explanation:
Why do many galaxies appear as
spirals? A striking example is
M101, shown above,
whose relatively close distance of about 22 million light years
allow it to be studied in some detail. Recent evidence indicates that a close gravitational interaction
with a neighboring galaxy created waves of high mass and condensed gas which continue to circle the
galaxy. These waves compress existing gas and cause
star formation.
One result is that
M101, also called the Pinwheel Galaxy,
has several extremely bright
star-forming regions (called HII regions)
spread across its spiral arms.
M101
is so large that its immense gravity distorts smaller nearby galaxies.
APOD: June 8, 1997 - M101: An Ultraviolet View
Explanation:
This giant spiral galaxy,
Messier 101 (M101), was photographed by the
Ultraviolet Imaging Telescope (UIT).
UIT flew into orbit as part of
the Astro 2 mission
on-board the Space Shuttle Endeavour in March 1995.
The image has been processed
so that the colors (purple to white) represent an increasing intensity of
ultraviolet light.
Pictures of galaxies like this one show mainly
clouds of gas containing newly formed stars many times more massive
than the sun, which glow strongly in ultraviolet light.
In contrast,
visible light pictures of galaxies tend to be dominated by the yellow
and red light of older stars.
Ultraviolet light,
invisible to the human eye, is blocked by
ozone in the atmosphere so ultraviolet pictures of
celestial objects must be taken from space.
APOD: June 27, 1995 - An Ultraviolet Image of M101
Explanation:
This giant spiral galaxy, Messier 101 (M101), was photographed
by the Ultraviolet Imaging Telescope onboard the Space Shuttle Endeavour
during the Astro-2 mission (March 2 - 18, 1995).
The image has been computer processed so that the colors represent
the intensity of ultraviolet light.
Pictures of galaxies like this one
show mainly clouds of gas containing
newly formed stars many times more massive than the sun,
which glow strongly in ultraviolet light.
In contrast, visible light pictures of galaxies
tend to be dominated by the yellow and red light of older stars.
Ultraviolet light, invisible to the human eye, is blocked by
ozone in the atmosphere so ultraviolet pictures of celestial objects
must be taken from space.