Scorpius is one of the constellations of the zodiac. Its name is Latin for scorpion. Scorpius is one of the 48 constellations identified by the Greek astronomer Ptolemy in the second century. It is an ancient constellation that pre-dated the Greeks. It lies between Libra to the west and Sagittarius to the east. It is a large constellation located in the southern hemisphere near the center of the Milky Way.
The Western astrological sign Scorpio of the tropical zodiac (October 23- November 21) differs from the astronomical constellation and the Hindu astrological sign of the sidereal zodiac (November 16- December 16). Astronomically, the sun is in Scorpius for just six days, from November 23 to November 28. Much of the difference is due to the constellation Ophiuchus, which is used by only a few astrologers. Scorpius corresponds to the nakshatras Anuradha, Jyeshtha, and Mula.
Scorpius from Chart XV of the Uranographia of Johann Bode (1801). Part of the scorpion’s body is overlapped by the lower left leg and foot of Ophiuchus. In the middle of the scorpion’s body lies the red star Antares. On this chart, Bode also gives Antares the alternative name Calbalakrab, from the Arabic meaning ‘scorpion’s heart’.
[http://www.ianridpath.com/startales/scorpius.htm]
In Greek mythology, the myths associated with Scorpio almost invariably also contain a reference to Orion. According to one of these myths it is written that Orion boasted to goddess Artemis and her mother, Leto, that he would kill every animal on the Earth. Although Artemis was known to be a hunter herself she offered protection to all creatures. Artemis and her mother Leto sent a scorpion to deal with Orion. The pair battled and the scorpion killed Orion. However, the contest was apparently a lively one that caught the attention of the king of the gods Zeus, who later raised the scorpion to heaven and afterwards, at the request of Artemis, did the same for Orion to serve as a reminder for mortals to curb their excessive pride. There is also a version that Orion was better than the goddess Artemis but said that Artemis was better than he and so Artemis took a liking to Orion. The god Apollo, Artemis’s twin brother, grew angry and sent a scorpion to attack Orion. After Orion was killed, Artemis asked Zeus to put Orion up in the sky. So every winter Orion hunts in the sky, but every summer he flees as the constellation of the scorpion comes.
The Babylonians called this constellation MUL.GIR.TAB- the ‘Scorpion,’ the signs can be literally read as ‘the (creature with) a burning sting.’
In some old descriptions the constellation of Libra is treated as the Scorpion’s claws. Libra was known as the Claws of the Scorpion in Babylonian (‘zibānītu’).
The Javanese people of Indonesia call this constellation Banyakangrem (‘the brooded swan’) or Kalapa Doyong (‘leaning coconut tree’) due to the shape similarity.
Constellation of Scorpius
[http://www.davidmalin.com/fujii/source/Sco_1.html]
Scorpius- July 15, 10:30 PM- Latitude 30° North, Longitude 95° West
[http://www.peoplesguidetothecosmos.com/constellations/scorpius.htm]
The constellation’s bright stars form a pattern like a longshoreman’s hook. Most of them are massive members of the nearest Scorpius-Centaurus OB association:
Antares, between σ and τ Scorpii, appears white in this WISE false color infrared image
Antares, also designated Alpha Scorpii, is on average the fifteenth-brightest star in the night sky, and the brightest star in the constellation of Scorpius. Its traditional name Antares derives from the Ancient Greek ‘Ἀντάρης,’ meaning ‘equal to- Ares’ (‘equal to-Mars’), due to the similarity of its reddish hue to the appearance of the planet Mars. Distinctly reddish when viewed with the naked eye, Antares is a slow irregular variable star that ranges in brightness from apparent magnitude +0.6 to +1.6. Often referred to as ‘the heart of the scorpion,’ Antares is flanked by Sigma and Tau Scorpii in the center of the constellation.
Classified as a red supergiant of spectral type M1.5Iab-Ib, Antares is likely among the largest of known stars. It is the brightest, most massive, and most evolved stellar member of the nearest OB association (the Scorpius- Centaurus Association, which contains thousands of stars with mean age 11 million years at a distance of approximately 170 parsecs (550 ly). Its exact size remains uncertain, but if placed at the center of the solar system it would reach to somewhere between the orbits of Mars and Jupiter. The mass is calculated to be around 12 times that of the Sun.
The brightness of Antares at visual wavelengths is about 10,000 times that of the Sun, but because the star radiates a considerable part of its energy in the infrared part of the spectrum, the true bolometric luminosity is around 100,000 times that of the Sun. The mass of the star has been calculated to be approximately 12 M☉. Comparison of the effective temperature and luminosity of Antares to theoretical evolutionary tracks for massive stars suggest a progenitor mass of 17 M☉ and an age of 12 million years. Massive stars like Antares are expected to become supernovae.
Antares is visible in the sky all night around May 31 of each year, when the star is at opposition to the Sun. At this time, Antares rises at dusk and sets at dawn as seen at the equator. For approximately two to three weeks on either side of November 30, Antares is not visible in the night sky, because it is near conjunction with the Sun; this period of invisibility is longer in the Northern Hemisphere than in the Southern Hemisphere, since the star’s declination is significantly south of the celestial equator.
Antares can also be occulted by the planet Venus (called a planetary lunar occultation), but these events are extremely rare. The last occultation of Antares by Venus took place on September 17, 525 BC; the next one will take place on November 17, 2400. Other planets have been calculated not to have occulted Antares over the last millennium, and nor will this occur during the next millennium, as the planets following the ecliptic always pass northward of Antares due to the actual planetary node positions and inclinations.
[https://en.wikipedia.org/wiki/Antares]
Lambda Scorpii, also named Shaula, is (despite being designated ‘Lambda’) the second-brightest star system in the constellation of Scorpius, and one of the brightest stars in the nighttime sky. The traditional name ‘Shaula’ comes from the Arabic ‘al-šawlā’ meaning ‘the raised [tail],’ as it is found in the tail of the scorpion (Scorpius). It is located some 570 light-years away from the Sun.
Spectroscopic and interferometric observations have shown that it is actually a triple system consisting of two B-type stars and a pre-main-sequence star. The primary star is a beta Cephei variable star with rapid brightness changes of about a hundredth of a magnitude. The pre-main-sequence star has an orbital period of 6 days and the B companion has a period of 1053 days. The three stars lie in the same orbital plane, strongly suggesting that they were formed at the same time. The masses of the primary, pre-main-sequence star and the B companion are 14.5, 2.0 and 10.6 solar masses, respectively. The age of the system is estimated to be in the range 10-13 million years.
[https://en.wikipedia.org/wiki/Lambda_Scorpii]
Theta Scorpii is a binary star in the southern zodiac constellation of Scorpius. The apparent visual magnitude of this star is +1.87, making it readily visible to the naked eye and one of the brightest stars in the night sky. It is approximately 300 light-years (90 parsecs) away from the Sun.
The two components are designated Theta Scorpii A (also named Sargas) and B. The primary (Theta Scorpii A) is an evolved bright giant star with a stellar classification of F0 II. With a mass 5.7 times that of the Sun, it has expanded to about 26 times the Sun’s radius. It is radiating 1,834 times as much luminosity as the Sun from its outer envelope at an effective temperature of 7,268K, giving it the yellow-white hued glow of an F-type star. This star is rotating rapidly, giving it an oblate shape with an equatorial radius 19% larger than the polar radius. The magnitude 5.36 companion (Theta Scorpii B) is at an angular separation of 6.470 arcseconds.
[https://en.wikipedia.org/wiki/Theta_Scorpii]
Delta Scorpii is a binary star (the presence of a third star in the system is still being debated) in the constellation of Scorpius. The primary component is named Dschubba.
The primary, Delta Scorpii A, is a B class subgiant surrounded by a disc of material spun off by the rapidly rotating star. The secondary, Delta Scorpii B, orbits every 10.5 years in a highly elongated elliptical orbit. Delta Scorpii A is a Gamma Cassiopeiae variable star. This type of star shows irregular slow brightness variations of a few hundredths of a magnitude due to material surrounding the star.
[https://en.wikipedia.org/wiki/Delta_Scorpii]
Scorpius X-1 is an X-ray source located roughly 9,000 light years away in the constellation Scorpius. Scorpius X-1 was the first extrasolar X-ray source discovered, and, aside from the Sun, it is the strongest apparent source of X-rays in the sky:
[https://en.wikipedia.org/wiki/Scorpius_X-1]
Scorpius X-1: This image from the Swift X-ray Telescope shows an X-ray nova (designated J1745-26) and Scorpius X-1, along with the scale of moon, as they would appear in the field of view from Earth.
We were able to interest NASA and the Air Force in funding an X-ray experiment, so, in 1960, we placed a small-aperture Geiger counter on a rocket to search for X-ray stars and lunar X-rays. Unfortunately, the flight failed when the rocket misfired. By the next year we had improved upon our experiment and prepared it to be launched again. We now had a more sensitive instrument that also had a large field of view, which increased the probability of both observing a X-ray source anywhere in the sky and receiving a sufficient number of photons to make detection of them statistically significant. In effect, the payload we designed and flew was 100 times more sensitive than any flown until then. But this attempt also failed when the door to the detector failed to open.
When our experiment finally launched on June 18, 1962, data revealed a very strong peak of radiation in the south. The source of this radiation did not appear when our optical photometer was pointed at the Moon, but, it did appear in our X-ray detector when we were pointing away from the Moon. After weeks of analysis, we concluded that the most likely source of the observed radiation was from outside the solar system, and that the strong peak was from the general direction of the Galactic center. The source was a double star system named Scorpius X-1 (Sco X-1 for short).
The discovery was beyond all we had hoped to find! Here was an object that emitted a thousand times more X-rays than the Sun, and a thousand times more energy in X-rays than in visible light! Clearly we were dealing with a new class of stellar objects in which physical processes not known in the laboratory were taking place. Soon after the announcement, the NRL group, led by Herbert Friedman, used a larger area detector with better angular resolution than the AS&E instrument to confirm our discovery of Sco X-1, as well as to observe the Crab Nebula.
[http://ecuip.lib.uchicago.edu/multiwavelength-astronomy/x-ray/impact/04.html]
Pismis 24-1, also known as HD 319718, is the brightest star of the open cluster Pismis 24 within the nebula NGC 6357 about 6,500 light-years away:
[https://en.wikipedia.org/wiki/Pismis_24-1]
Massive Stars in Open Cluster Pismis 24
How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it a record holder. This star is the brightest object located just to the right of the gas front in the above image. Close inspection of images taken recently with the Hubble Space Telescope, however, have shown that Pismis 24-1 derives its brilliant luminosity not from a single star but from three at least. Component stars would still remain near 100 solar masses, making them among the more massive stars currently on record. Toward the image left, stars are still forming in the associated emission nebula NGC 6357, including several that appear to be breaking out and illuminating a spectacular cocoon.
[https://apod.nasa.gov/apod/ap061219.html]
An artist’s impression of PSR B1620-26 b staring at its parent stars
PSR B1620-26 b is an extrasolar planet located approximately 12,400 light-years away from Earth in the constellation of Scorpius. It bears the unofficial nicknames ‘Methuselah’ and ‘the Genesis planet’ due to its extreme age. The planet is in a circumbinary orbit around the two stars of PSR B1620-26 (which are a pulsar (PSR B1620-26 A) and a white dwarf (WD B1620-26)) and is the first circumbinary planet ever confirmed. It is also the first planet found in a globular cluster. The planet is one of the oldest known extrasolar planets, believed to be about 12.7 billion years old.
[https://en.wikipedia.org/wiki/PSR_B1620-26_b]
Planet HD 147513 b
[https://upload.wikimedia.org/wikipedia/commons/c/c0/Planet_HD_147513_b.png]
HD 147513 (62 G. Scorpii) is a Sun-like main sequence star with a stellar classification of G1VH-04. It has about 11% greater mass than the Sun, and is considered young with an estimated age of 400 million years. As such, it has a similar luminosity to the Sun despite being more massive. With an apparent magnitude of 5.38, it is visible to the naked eye from suburban skies. It lies some 42 light years from the Sun.
HD 147513 b is an exoplanet, orbiting the star HD 147513. It is at least 21% more massive than Jupiter. But unlike Jupiter, it orbits the star much closer, mean distance being only a third more than Earth’s distance from the Sun. Its orbit is also eccentric; at periastron, it is closer to its star than Earth is from the Sun, whereas at apastron, it is further from its star than Mars to the Sun, finding itself on the outer edge of the habitable zone.
[https://en.wikipedia.org/wiki/HD_147513]
Due to its location straddling the Milky Way, Scorpius contains many deep-sky objects such as the open clusters Messier 4 (NGC 6121), and Messier 7 (the Ptolemy Cluster):
The Dark River to Antares
Connecting the Pipe Nebula to the colorful region near bright star Antares is a dark cloud dubbed the Dark River, flowing from the picture’s left edge. Murky looking, the Dark River’s appearance is caused by dust obscuring background starlight, although the dark nebula contains mostly hydrogen and molecular gas. Surrounded by dust, Antares, a red supergiant star, creates an unusual bright yellowish reflection nebula. Above it, bright blue double star Rho Ophiuchi is embedded in one of the more typical bluish reflection nebulae, while red emission nebulae are also scattered around the region. Globular star cluster M4 is just seen above and right of Antares, though it lies far behind the colorful clouds, at a distance of some 7,000 light-years. The Dark River itself is about 500 light years away. The colorful skyscape is a mosaic of telescopic images spanning nearly 10 degrees (20 Full Moons) across the sky in the constellation of the Scorpion (Scorpius).
[https://apod.nasa.gov/apod/ap150222.html]
M7: Open Star Cluster in Scorpius
M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of the Scorpion (Scorpius). M7 contains about 100 stars in total, is about 200 million years old, spans 25 light-years across, and lies about 1,000 light-years away. The featured wide-angle image was taken near the city of Belo Horizonte in Brazil. The M7 star cluster has been known since ancient times, being noted by Ptolemy in the year 130 AD. Also visible are a dark dust cloud on the lower right, and, in the background, literally millions of unrelated stars towards the Galactic center.
[https://apod.nasa.gov/apod/ap160713.html]
NGC 6231 is another open cluster in Scorpius, located near Zeta Scorpii:
The Dark Tower in Scorpius
In silhouette against a crowded star field toward the constellation Scorpius, this dusty cosmic cloud evokes for some the image of an ominous dark tower. In fact, clumps of dust and molecular gas collapsing to form stars may well lurk within the dark nebula, a structure that spans almost 40 light-years across this gorgeous telescopic portrait. Known as a cometary globule, the swept-back cloud, extending from the lower right to the head (top of the tower) left and above center, is shaped by intense ultraviolet radiation from the OB association of very hot stars in NGC 6231, off the upper edge of the scene. That energetic ultraviolet light also powers the globule's bordering reddish glow of hydrogen gas. Hot stars embedded in the dust can be seen as bluish reflection nebulae. This dark tower, NGC 6231, and associated nebulae are about 5,000 light-years away.
[https://apod.nasa.gov/apod/ap130106.html]
NGC 6302, also called the Bug or Butterfly Nebula, is a bipolar planetary nebula:
[https://en.wikipedia.org/wiki/NGC_6231]
Butterfly Emerges from Stellar Demise in Planetary Nebula NGC 6302
This celestial object looks like a delicate butterfly. But it is far from serene. What resemble dainty butterfly wings are actually roiling cauldrons of gas heated to more than 36,000 degrees Fahrenheit. The gas is tearing across space at more than 600,000 miles an hour- fast enough to travel from Earth to the moon in 24 minutes!
A dying star that was once about five times the mass of the Sun is at the center of this fury. It has ejected its envelope of gases and is now unleashing a stream of ultraviolet radiation that is making the cast-off material glow. This object is an example of a planetary nebula, so-named because many of them have a round appearance resembling that of a planet when viewed through a small telescope.
The Wide Field Camera 3 (WFC3), a new camera aboard NASA’s Hubble Space Telescope, snapped this image of the planetary nebula, catalogued as NGC 6302, but more popularly called the Bug Nebula or the Butterfly Nebula. WFC3 was installed by NASA astronauts in May 2009, during the servicing mission to upgrade and repair the 19-year-old Hubble telescope.
NGC 6302 lies within our Milky Way galaxy, roughly 3,800 light-years away in the constellation Scorpius. The glowing gas is the star’s outer layers, expelled over about 2,200 years. The ‘butterfly’ stretches for more than two light-years, which is about half the distance from the Sun to the nearest star, Alpha Centauri.
The central star itself cannot be seen, because it is hidden within a doughnut-shaped ring of dust, which appears as a dark band pinching the nebula in the center. The thick dust belt constricts the star’s outflow, creating the classic ‘bipolar’ or hourglass shape displayed by some planetary nebulae.
The star’s surface temperature is estimated to be about 400,000 degrees Fahrenheit, making it one of the hottest known stars in our galaxy. Spectroscopic observations made with ground-based telescopes show that the gas is roughly 36,000 degrees Fahrenheit, which is unusually hot compared to a typical planetary nebulae.
The WFC3 image reveals a complex history of ejections from the star. The star first evolved into a huge red-giant star, with a diameter of about 1,000 times that of our Sun. It then lost its extended outer layers. Some of this gas was cast off from its equator at a relatively slow speed, perhaps as low as 20,000 miles an hour, creating the doughnut-shaped ring. Other gas was ejected perpendicular to the ring at higher speeds, producing the elongated ‘wings’ of the butterfly-shaped structure. Later, as the central star heated up, a much faster stellar wind, a stream of charged particles travelling at more than 2 million miles an hour, plowed through the existing wing-shaped structure, further modifying its shape.
The image also shows numerous finger-like projections pointing back to the star, which may mark denser blobs in the outflow that have resisted the pressure from the stellar wind.
The nebula’s outer edges are largely due to light emitted by nitrogen, which marks the coolest gas visible in the picture. WFC3 is equipped with a wide variety of filters that isolate light emitted by various chemical elements, allowing astronomers to infer properties of the nebular gas, such as its temperature, density, and composition.
The white-colored regions are areas where light is emitted by sulfur. These are regions where fast-moving gas overtakes and collides with slow-moving gas that left the star at an earlier time, producing shock waves in the gas (the bright white edges on the sides facing the central star). The white blob with the crisp edge at upper right is an example of one of those shock waves.
NGC 6302 was imaged on July 27, 2009 with Hubble’s Wide Field Camera 3 in ultraviolet and visible light. Filters that isolate emissions from oxygen, helium, hydrogen, nitrogen, and sulfur from the planetary nebula were used to create this composite image.
[http://www.nasa.gov/mission_pages/hubble/multimedia/ero/ero_ngc6302.html]
NGC 6334, also known as the Cat’s Paw Nebula, is an emission nebula and star-forming region in Scorpius:
NGC 6334: The Cat’s Paw Nebula
Nebulas are perhaps as famous for being identified with familiar shapes as perhaps cats are for getting into trouble. Still, no known cat could have created the vast Cat’s Paw Nebula visible in Scorpius. At 5,500 light years distant, Cat’s Paw is an emission nebula with a red color that originates from an abundance of ionized hydrogen atoms. Alternatively known as the Bear Claw Nebula or NGC 6334, stars nearly ten times the mass of our Sun have been born there in only the past few million years. Pictured above is a deep field image of the Cat’s Paw nebula.
[http://apod.nasa.gov/apod/ap140618.html]
NGC 6357 (also Lobster Nebula) is a diffuse nebula in Scorpius. It contains many proto-stars and young stars. The nebula contains Pismis 24-1, one of the most luminous stars known:
[http://www.constellation-guide.com/constellation-list/scorpius-constellation/]
NGC 6357: The Lobster Nebula
Why is the Lobster Nebula forming some of the most massive stars known? No one is yet sure. Near the more obvious Cat's Paw nebula on the upper right, the Lobster Nebula, on the lower left and cataloged as NGC 6357, houses the open star cluster Pismis 24, home to these tremendously bright and blue stars. The overall red glow near the inner star forming region results from the emission of ionized hydrogen gas. The surrounding nebula, featured here, holds a complex tapestry of gas, dark dust, stars still forming, and newly born stars. The intricate patterns are caused by complex interactions between interstellar winds, radiation pressures, magnetic fields, and gravity. The full zoomable version of this image contains about two billion pixels, making it one of the largest space images ever released. NGC 6357 spans about 400 light years and lies about 8,000 light years away toward the constellation of the Scorpion.
[https://apod.nasa.gov/apod/ap170207.html]
V745 Sco is a binary system composed of a red giant and a white dwarf in close orbit:
V745 Sco: Two stars, three dimensions, and oodles of energy
A new 3D model of an explosion from the V745 Sco system is helping astronomers learn more about this volatile system. V745 Sco is a binary system where a red giant and a white dwarf star are in very close orbit around one another. The intense gravitational forces from the white dwarf pull the outer layers of the red giant onto the smaller star’s surface, triggering explosions. Astronomers observed V745 Sco about two weeks after its most recent outburst in 2014 with Chandra, enabling them to generate this new 3D model.
For decades, astronomers have known about irregular outbursts from the double star system V745 Sco, which is located about 25,000 light years from Earth. Astronomers were caught by surprise when previous outbursts from this system were seen in 1937 and 1989. When the system erupted on February 6, 2014, however, scientists were ready to observe the event with a suite of telescopes including NASA’s Chandra X-ray Observatory.
V745 Sco is a binary star system that consists of a red giant star and a white dwarf locked together by gravity. These two stellar objects orbit so closely around one another that the outer layers of the red giant are pulled away by the intense gravitational force of the white dwarf. This material gradually falls onto the surface of the white dwarf. Over time, enough material may accumulate on the white dwarf to trigger a colossal thermonuclear explosion, causing a dramatic brightening of the binary called a nova. Astronomers saw V745 Sco fade by a factor of a thousand in optical light over the course of about 9 days.
Astronomers observed V745 Sco with Chandra a little over two weeks after the 2014 outburst. Their key finding was it appeared that most of the material ejected by the explosion was moving towards us. To explain this, a team of scientists from the INAF-Osservatorio Astronomico di Palermo, the University of Palermo, and the Harvard-Smithsonian Center for Astrophysics constructed a three-dimensional (3D) computer model of the explosion, and adjusted the model until it explained the observations. In this model they included a large disk of cool gas around the equator of the binary caused by the white dwarf pulling on a wind of gas streaming away from the red giant.
The computer calculations showed that the nova explosion’s blast wave and ejected material were likely concentrated along the north and south poles of the binary system. This shape was caused by the blast wave slamming into the disk of cool gas around the binary. This interaction caused the blast wave and ejected material to slow down along the direction of this disk and produce an expanding ring of hot, X-ray emitting gas. X-rays from the material moving away from us were mostly absorbed and blocked by the material moving towards Earth, explaining why it appeared that most of the material was moving towards us.
In the figure (pictured above) showing the new 3D model of the explosion, the blast wave is yellow, the mass ejected by the explosion is purple, and the disk of cooler material, which is mostly untouched by the effects of the blast wave, is blue. The cavity visible on the left side of the ejected material (see the labeled version) is the result of the debris from the white dwarf’s surface being slowed down as it strikes the red giant. Below is an optical image from Siding Springs Observatory in Australia.
An extraordinary amount of energy was released during the explosion, equivalent to about 10 million trillion hydrogen bombs. The authors estimate that material weighing about one tenth of the Earth’s mass was ejected.
While this stellar-sized belch was impressive, the amount of mass ejected was still far smaller than the amount what scientists calculate is needed to trigger the explosion. This means that despite the recurrent explosions, a substantial amount of material is accumulating on the surface of the white dwarf. If enough material accumulates, the white dwarf could undergo a thermonuclear explosion and be completely destroyed. Astronomers use these so-called Type Ia supernovas as cosmic distance markers to measure the expansion of the Universe.
The scientists were also able to determine the chemical composition of the material expelled by the nova. Their analysis of this data implies that the white dwarf is mainly composed of carbon and oxygen.
[http://chandra.harvard.edu/photo/2017/v745/index.html]
G352.7-0.1 is a supernova remnant located in Scorpius:
G352.7-0.1: Supernova cleans up its surroundings
A supernova remnant is created when a massive star runs out of fuel and explodes with an expanding debris field. Astronomers have found a supernova remnant that is sweeping up material weighing about 45 times the mass of the Sun as it expands. The supernova remnant is called G352.7-0.1 and is located about 24,000 light years from Earth. A new composite image shows G352.7-0.1 in X-rays, radio, infrared, and optical data.
Supernovas are the spectacular ends to the lives of many massive stars. These explosions, which occur on average twice a century in the Milky Way, can produce enormous amounts of energy and be as bright as an entire galaxy. These events are also important because the remains of the shattered star are hurled into space. As this debris field - called a supernova remnant - expands, it carries the material it encounters along with it.
The supernova remnant G352.7-0.1 (or, G352 for short) - has swept up material equivalent to about 45 times the mass of the Sun, as it expands. Although this is not an exceptionally large amount, astronomers have found that several other properties of the supernova remnant are unusual. First, they found that this supernova remnant has a very different shape in radio data compared to that in X-rays. Most of the radio emission is shaped like an ellipse, contrasting with the X-ray emission that fills in the center of the radio ellipse. This is seen in a new composite image of G352 that contains X-rays from NASA’s Chandra X-ray Observatory in blue and radio data from the National Science Foundation’s Karl G. Jansky Very Large Array in pink. These data have also been combined with infrared data from the Spitzer Space Telescope in orange, and optical data from the Digitized Sky Survey in white. (The infrared emission to the upper left and lower right are not directly related to the supernova remnant.)
A recent study suggests that, surprisingly, the X-ray emission in G352 is dominated by the hotter (about 30 million degrees Celsius) debris from the explosion, rather than cooler (about 2 million degrees) emission from surrounding material that has been swept up by the expanding shock wave. This is curious because astronomers estimate that G352 exploded about 2,200 years ago, and supernova remnants of this age usually produce X-rays that are dominated by swept-up material. Scientists are still trying to come up with an explanation for this behavior.
Astronomers also conducted a search for a neutron star that may have been produced by the supernova explosion. They did not find any hints of a neutron star in G352, another astronomical puzzle involved with this system. One possibility is simply that the neutron star is too faint to be detected or that the supernova created a black hole instead.
[http://chandra.harvard.edu/photo/2014/g352/index.html]
This is a picture showing both the star Antares and the planet Saturn:
Saturn in the Milky Way
Saturn is near opposition in planet Earth’s sky. Rising at sunset and shining brightly throughout the night, it also lies near a line-of-sight to crowded star-fields, nebulae, and obscuring dust clouds along the Milky Way. Whitish Saturn is up and left of center in this gorgeous central Milky Way skyscape, a two panel mosaic recorded earlier this month. You can find the bright planet above the bowl of the dusty Pipe nebula, and just beyond the end of a dark river to Antares, alpha star of the constellation Scorpius. For now the best views of the ringed giant planet are from the Saturn-orbiting Cassini spacecraft, though. Diving close, Cassini’s Grand Finale orbit number 8 is in progress.
[https://apod.nasa.gov/apod/ap170610.html]
[https://en.wikipedia.org/wiki/Scorpius]
No comments:
Post a Comment