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Astronomy Picture of the Day |
APOD: 2025 February 18 – Thor's Helmet versus the Seagull
Explanation:
Seen as a seagull and a duck,
these nebulae are not the only
cosmic clouds to
evoke images of flight.
But both are winging their way across this broad
celestial landscape, spanning almost 7 degrees across
planet Earth's
night sky toward the constellation of the Big Dog
(Canis Major).
The expansive Seagull
(top center)
is itself composed of two major cataloged
emission nebulas.
Brighter NGC 2327 forms the head with the more diffuse
IC 2177 as the wings and body.
Impressively, the Seagull's
wingspan would correspond to about 250
light-years at
the nebula's estimated distance of 3,800 light-years.
At the lower right, the Duck appears much more compact and
would span only about 50 light-years given its
15,000 light-year distance estimate.
Blown by
energetic winds from an extremely massive,
hot star near its center, the Duck nebula is cataloged
as NGC 2359.
Of course, the Duck's thick body and winged appendages
also lend it the slightly more
dramatic popular moniker,
Thor's Helmet.
APOD: 2024 January 9 – Thor's Helmet
Explanation:
Thor not only has
his own day
(Thursday), but a helmet in the heavens.
Popularly called Thor's Helmet,
NGC 2359
is a hat-shaped cosmic cloud with wing-like appendages.
Heroically sized even for a
Norse god,
Thor's Helmet is about 30 light-years across.
In fact, the cosmic head-covering is more like
an interstellar bubble, blown with a fast
wind from the bright, massive star near the bubble's center.
Known as a
Wolf-Rayet star, the central star is an extremely
hot giant thought to be in a brief,
pre-supernova stage of
evolution.
NGC 2359 is located about 15,000
light-years away toward the constellation of the
Great Overdog.
This remarkably sharp image
is a mixed cocktail of data from
narrowband filters,
capturing not only
natural looking stars but details of
the nebula's
filamentary structures.
The star in the center of Thor's Helmet is expected to
explode in a spectacular
supernova sometime within the next few thousand years.
APOD: 2022 December 20 - Thors Helmet
Explanation:
Thor not only has
his own day
(Thursday), but a helmet in the heavens.
Popularly called Thor's Helmet,
NGC 2359
is a hat-shaped cosmic cloud with wing-like appendages.
Heroically sized even for a
Norse god,
Thor's Helmet is about 30 light-years across.
In fact, the cosmic head-covering is more like
an interstellar bubble, blown with a fast
wind from the bright, massive star near the bubble's center.
Known as a
Wolf-Rayet star, the central star is an extremely
hot giant thought to be in a brief,
pre-supernova stage of evolution.
NGC 2359 is located about
15,000 light-years away toward the constellation of the
Great Overdog.
This remarkably sharp image
is a mixed cocktail of data from
narrowband filters,
capturing not only
natural looking stars but details of
the nebula's
filamentary structures.
The star in the center of Thor's Helmet is expected to
explode in a spectacular
supernova sometime within the next few thousand years.
APOD: 2021 July 20 - Thor's Helmet
Explanation:
Thor not only has
his own day
(Thursday), but a helmet in the heavens.
Popularly called Thor's Helmet,
NGC 2359
is a hat-shaped cosmic cloud with wing-like appendages.
Heroically sized even for a
Norse god,
Thor's Helmet is about 30 light-years across.
In fact, the cosmic head-covering is more like
an interstellar bubble, blown with a fast
wind from the bright, massive star near the bubble's center.
Known as a
Wolf-Rayet star, the central star is an extremely
hot giant thought to be in a brief,
pre-supernova stage of evolution.
NGC 2359 is located about
15,000 light-years away toward the constellation of the
Great Overdog.
This remarkably sharp image
is a mixed cocktail of data from broadband and
narrowband filters,
capturing not only
natural looking stars but details of
the nebula's
filamentary structures.
The star in the center of Thor's Helmet is expected to
explode in a spectacular
supernova sometime within the next few thousand years.
APOD: 2020 June 12 - NGC 2359: Thor's Helmet
Explanation:
NGC 2359 is a helmet-shaped cosmic cloud with
wing-like appendages popularly called Thor's Helmet.
Heroically sized even for a
Norse god,
Thor's Helmet is about 30 light-years across.
In fact, the helmet is more like
an interstellar bubble, blown as a fast
wind from the bright, massive star near the bubble's center inflates
a region within the surrounding molecular cloud.
Known as a
Wolf-Rayet star,
the central star is an extremely hot giant thought to be in a brief,
pre-supernova stage of evolution.
NGC 2359 is located about
15,000 light-years away in the constellation of the
Great Overdog.
The remarkably sharp image
is a mixed cocktail of data from broadband and narrowband filters using
three different telescopes.
It captures natural looking stars and the details of
the nebula's
filamentary structures.
The predominant bluish hue is strong emission from doubly ionized
oxygen atoms
in the glowing gas.
APOD: 2019 February 16 - NGC 2359: Thor's Helmet
Explanation:
NGC 2359 is a helmet-shaped cosmic cloud with
wing-like appendages popularly called Thor's Helmet.
Heroically sized even for a
Norse god,
Thor's Helmet is about 30 light-years across.
In fact, the helmet is more like
an interstellar bubble, blown as a fast
wind from the bright, massive star near the bubble's center inflates
a region within the surrounding molecular cloud.
Known as a
Wolf-Rayet star, the central star is an
extremely hot giant thought to be in a brief,
pre-supernova stage of evolution.
NGC 2359
is located about
15,000 light-years away in the constellation
Canis
Major.
The remarkably detailed image
is a mixed cocktail of data from broadband and narrowband filters
that captures natural looking stars and the glow of
the nebula's
filamentary structures.
It highlights a blue-green color from strong emission
due to oxygen
atoms in the glowing gas.
APOD: 2018 March 16 - The Seagull and The Duck
Explanation:
Seen as a seagull and a duck, these nebulae are
not the only
cosmic clouds to
evoke images of flight.
But both are winging their way across this broad
celestial landscape, spanning almost 7 degrees across
planet Earth's night sky
toward the constellation
Canis Major.
The expansive Seagull
(top center)
is
itself composed of
two major cataloged
emission nebulae.
Brighter NGC 2327 forms the head with the more diffuse
IC 2177 as the wings and body.
Impressively, the Seagull's
wingspan would correspond to about 250 light-years at
the nebula's estimated distance of 3,800 light-years.
At the lower right, the Duck appears much more compact and
would span only about 50 light-years given its
15,000 light-year distance estimate.
Blown by energetic winds from an extremely massive,
hot star near its center, the Duck nebula is cataloged
as NGC 2359.
Of course, the Duck's thick body and winged appendages
also lend it the slightly more dramatic popular moniker,
Thor's Helmet.
APOD: 2017 November 1 - Thor's Helmet Emission Nebula
Explanation:
This helmet-shaped cosmic cloud with
wing-like appendages is popularly called
Thor's Helmet.
Heroically sized even for a
Norse god,
Thor's Helmet spans about 30 light-years across.
In fact, the helmet is more like
an interstellar bubble, blown as a fast
wind -- from the
bright star near the center of the bubble's blue-hued region -- sweeps
through a surrounding molecular cloud.
This star, a
Wolf-Rayet star,
is a massive and extremely hot
giant star thought to be in a brief,
pre-supernova stage of evolution.
Cataloged as NGC 2359, the
emission nebula
is located about 12,000
light-years away toward the constellation of the Big Dog
(Canis
Major).
The sharp image, made using broadband and narrowband filters,
captures striking details of
the nebula's
filamentary gas and dust structures.
The blue color originates from strong emission from
oxygen atoms in the nebula.
APOD: 2014 February 15 - NGC 2359: Thor's Helmet
Explanation:
This helmet-shaped cosmic cloud with
wing-like appendages is popularly called Thor's Helmet.
Heroically sized even for a
Norse god,
Thor's Helmet is about 30 light-years across.
In fact, the helmet is more like
an interstellar bubble, blown as a fast
wind from the bright, massive star near the bubble's center sweeps
through a surrounding molecular cloud.
Known as a
Wolf-Rayet star, the central star is an
extremely hot giant thought to be in a brief,
pre-supernova stage of evolution.
Cataloged as NGC 2359, the
nebula is located about
15,000 light-years away in the constellation
Canis
Major.
The sharp
image, made using broadband and narrowband filters,
captures striking details of
the nebula's
filamentary structures.
It shows off a blue-green color from strong emission
due to oxygen atoms in the glowing gas.
APOD: 2013 March 7 - Thor's Helmet
Explanation:
This helmet-shaped cosmic cloud with
wing-like appendages is popularly called Thor's Helmet.
Heroically sized even for a
Norse god,
Thor's Helmet is about 30 light-years across.
In fact, the helmet is actually more like
an interstellar bubble, blown as a fast
wind from the bright, massive star near the bubble's center sweeps
through a surrounding molecular cloud.
Known as a
Wolf-Rayet star, the central star is an
extremely hot giant thought to be in a brief,
pre-supernova stage of evolution.
Cataloged as NGC 2359, the
nebula is located about
15,000 light-years away in the constellation
Canis
Major.
The sharp image,
made using broadband and narrowband filters, captures striking details of
the nebula's
filamentary structures.
It shows off a blue-green color from strong emission
due to oxygen atoms in the glowing gas.
APOD: 2010 June 5 - Thor's Helmet
Explanation:
This helmet-shaped cosmic cloud with
wing-like appendages is popularly called
Thor's
Helmet.
Heroically sized even for a
Norse god,
Thor's Helmet is about 30 light-years across.
In fact, the helmet is actually more like
an interstellar bubble, blown as a fast
wind from the bright, massive star near the bubble's center sweeps
through a surrounding molecular cloud.
Known as a
Wolf-Rayet star, the central star is an
extremely hot giant thought to be in a brief,
pre-supernova stage of evolution.
Cataloged as NGC 2359, the nebula is located about
15,000 light-years away in the constellation
Canis
Major.
The
sharp
image, made using broadband and narrowband filters,
captures striking details of the
nebula's filamentary structures.
It shows off a blue-green color from strong emission
due to oxygen atoms in the glowing gas.
APOD: 2010 March 19 - The Seagull and The Duck
Explanation:
Seen as a seagull and a duck, these nebulae are
not the only
cosmic clouds to
evoke images of flight.
But both are winging their way across this broad
celestial landscape, spanning almost 7 degrees across
planet Earth's night sky
toward the constellation
Canis Major.
The expansive Seagull
(upper left) is itself composed
of two major cataloged
emission nebulae.
Brighter NGC 2327 forms the head with the more diffuse
IC 2177 as the wings and body.
Impressively, the Seagull's
wingspan would correspond to about 250 light-years at
an estimated distance of 3,800 light-years.
At the lower right, the Duck appears much more compact and
would span only about 50 light-years given its
15,000 light-year distance estimate.
Blown by energetic winds from an extremely massive,
hot star near its center, the Duck nebula is cataloged
as NGC 2359.
Of course, the Duck's thick body and winged appendages
also lend it a more dramatic popular moniker --
Thor's Helmet.
APOD: 2009 March 12 - Thor's Helmet (NGC 2359) and Planetary Nebula
Explanation:
At the right, Thor's Helmet (NGC 2359) seems to gaze across
a lovely star field.
The broad skyscape
itself covers about 1.5 degrees or 3 full moons
toward the constellation Canis Major.
A close look at the lower left corner of the image
might identify
the object of the cosmic stare as a
faint, round nebula.
Heroically sized even for a Norse god,
Thor's
Helmet is about 30 light-years across.
The helmet is actually more like an interstellar bubble, blown as
a fast wind from the bright, massive star
near the bubble's center sweeps through a surrounding molecular cloud.
Known as a
Wolf-Rayet star,
the central star is an extremely hot giant
thought to be in a brief, pre-
supernova stage of evolution.
In contrast, the faint, round nebula is a
planetary nebula,
the gaseous shroud of a dying lower mass star.
The distance to Thor's Helmet is estimated to be about 15,000
light-years.
APOD: 2008 January 17 - Thor's Emerald Helmet
Explanation:
This helmet-shaped cosmic cloud with
wing-like appendages is popularly called
Thor's
Helmet.
Heroically sized even for a
Norse god,
Thor's Helmet is about 30 light-years across.
In fact, the helmet is actually more like
an interstellar bubble, blown as a fast
wind from the bright, massive star near the bubble's center sweeps
through a surrounding molecular cloud.
Known as a
Wolf-Rayet star, the central star is an
extremely hot giant thought to be in a brief,
pre-supernova stage of evolution.
Cataloged as NGC 2359, the nebula is located about
15,000 light-years away in the constellation
Canis
Major.
The sharp
image captures striking details of the
nebula's filamentary structures and also
records an almost emerald color from strong emission
due to oxygen atoms in the glowing gas.
APOD: 2007 January 30 - Thor's Helmet from CFHT
Explanation:
NGC 2359 is a striking emission nebula with an impressive popular name - Thor's
Helmet
Sure, its suggestive winged appearance might lead some to refer
to it as the "duck nebula", but if you were a nebula which name
would you choose?
By any name NGC 2359 is a bubble-like nebula some 30 light-years
across, blown by energetic winds from an extremely
hot star seen near
the center and classified as a Wolf-Rayet star.
Wolf-Rayet stars
are rare massive blue giants which develop
stellar winds
with speeds of millions of kilometers per hour.
Interactions with a nearby large
molecular cloud are thought
to have contributed to this nebula's more complex shape and
curved bow-shock structures.
NGC 2359
is about 15,000 light-years distant toward
the constellation
Canis Major.
APOD: 2006 February 2 - Thor's Helmet in H-Alpha
Explanation:
Near picture center, the helmet-shaped structure with
wing-like appendages is popularly called
Thor's Helmet.
Cataloged as NGC 2359, the striking nebula is located about
15,000 light-years away in the constellation
Canis
Major.
The helmet is actually more like
a
cosmic bubble, blown as the
wind from the bright, massive star near the bubble's center sweeps
through the surrounding molecular cloud.
Known as a
Wolf-Rayet star, the energetic star is a blue giant
thought to be in a brief,
pre-supernova stage of evolution.
The remarkable color composite
combines broad and narrow band images -
including a deep exposure recorded with an
H-alpha filter.
The H-alpha image traces the light from
the region's glowing atomic hydrogen gas.
Heroically sized even for a
Norse god,
this Thor's Helmet is about 30 light-years across.
APOD: 2005 November 19 - NGC 2359: Thor's Helmet
Explanation:
NGC 2359 is a striking emission nebula
with an impressive
popular name - Thor's Helmet.
Sure, its suggestive winged appearance might lead some to refer
to it as the "duck nebula", but if you were a nebula which name
would you choose?
By any name NGC 2359 is a bubble-like nebula some 30 light-years
across, blown by energetic winds from an extremely
hot star seen near
the center and classified as a Wolf-Rayet star.
Wolf-Rayet stars
are rare massive blue giants which develop
stellar winds with speeds of millions of kilometers per hour.
Interactions with
a nearby large molecular cloud are thought
to have contributed to this nebula's more complex shape and
curved bow-shock structures.
NGC 2359
is about 15,000
light-years distant toward
the constellation
Canis Major.
APOD: 2002 December 5 - NGC 2359: Thor's Helmet
Explanation:
NGC 2359 is a striking emission nebula
with an impressive
popular name - Thor's Helmet.
Sure, its suggestive winged appearance might lead some to refer
to it as the "duck nebula", but if you were a nebula which name
would you choose?
By any name NGC 2359 is a bubble-like nebula some 30 light-years
across, blown by energetic winds from an extremely
hot star seen near
the center and classified as a Wolf-Rayet star.
Wolf-Rayet stars
are rare massive blue giants which develop
stellar winds with speeds of millions of kilometers per hour.
Interactions with
a nearby large molecular cloud are thought
to have contributed to this nebula's more complex shape and
curved bow-shock structures.
NGC 2359 is about 15,000
light-years distant toward
the constellation
Canis Major.
APOD: September 28, 1997 - A Wolf Rayet Star Bubble
Explanation:
What's a Wolf-Rayet star, and how did it create that spherical bubble and
sweeping arc? A
Wolf-Rayet
star is a star that originated with a
mass over 40 times that of our
Sun.
An extremely
hot, luminous star,
it has since expelled shells of material through its strong
stellar
wind which could account for the
bubble shaped nebula that surrounds it.
But astronomers are unsure how the central Wolf-Rayet
created both the bubble and the arc seen above, and
even whether it acted alone in doing so. Together, this bubble and the arc
are known as NGC 2359.
APOD: January 3, 1997 - A Wolf-Rayet Star Blows Bubbles
Explanation: Wolf-Rayet stars can blow bubbles. These
unusual stars are much hotter and more luminous than our Sun.
All extremely massive stars will eventually evolve though a Wolf-Rayet
phase. Approximately 200
Wolf-Rayet stars
are known in our Milky Way Galaxy.
Wolf-Rayet stars
generate bubbles
because they continually eject their outer atmosphere as a stellar
wind. This outgoing wind of particles typically carries away
more than the mass of our Earth each
year! The wind is caused by atmospheric particles absorbing outgoing starlight,
although many details of this process are unknown. The Wolf-Rayet
is the brightest star in the above picture
and is in the center of the large bubble in the nebula known as NGC 2359.
APOD: January 2, 1997 - Bubbles and Arcs in NGC 2359
Explanation: What caused the bubbles and arcs in NGC 2359?
The main suspect is the Wolf-Rayet star
in the center of one of the bubbles - visible slightly below and
to the right of the center of the above photograph.
Most Wolf-Rayet stars are known to be massive, highly luminous
stars that continually cast off material in a stellar wind - which
commonly form bubbles
in the interstellar medium.
But the unusual structure of the NGC 2359 arcs
indicate something more complex
is going on. Is the star moving supersonically?
Is there another energetic star in the vicinity? Future observations
may give more pieces to this picturesque puzzle.
APOD: August 26, 1996 - A Wolf-Rayet Star Bubble
Explanation:
What's a Wolf-Rayet star, and how did it create that spherical bubble and
sweeping arc?
A
Wolf-Rayet
star is a star that originated with a
mass over 40 times that of our
Sun.
An extremely
hot, luminous star,
it has since expelled shells of material through its strong
stellar
wind which could account for the
bubble shaped nebula that surrounds it.
But astronomers are unsure how the central Wolf-Rayet
created both the bubble and the arc seen above, and
even whether it acted alone in doing so. Together, this bubble and the arc
are known as NGC 2359.