SN 2008ax

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SN 2008ax
SN2008axHunterWilson.jpg
Position of SN 2008ax in NGC 4490; image courtesy of Hunter Wilson
Event typeSupernova
Type Ib [1]
Date3 March 2008
Constellation Canes Venatici
Right ascension 12h 30m 40.80s [2]
Declination +41° 38 16.1 [2]
Epoch J2000.0
Galactic coordinates b = 137.95°, l = +74.88° [2]
Distance31  Mly (9.6  Mpc) [3]
SourceNGC 4490
Peak apparent magnitude +13.0 [4]

SN 2008ax was a helium-rich type Ib core-collapse supernova in the interacting galaxy NGC 4490. [3] It was independently discovered on 3 March 2008 by LOSS [5] and 4 March by Koichi Itagaki. [6] The site had been monitored six hours before discovery, thus constraining the time of the explosion breakout. [3] It was the third-brightest supernova of 2008. [7] The brightness in the B-band peaked about 20 days after the explosion. [3] X-ray emissions were detected from the event, which are most likely the result of shock heating from the supernova ejecta and circumstellar material. [8]

Images of the source location made using the Hubble Space Telescope in 2011 and 2013 were used to identify the progenitor. If it was a single star, the images are compatible with a supergiant star with a class of B to mid-A type. However, this is not favored by models which indicate the progenitor had a relatively low mass of 4–5  M and extended hydrogen-rich atmosphere with a radius of 30–40  R . An alternative, more plausible model suggests the progenitor was part of an interacting binary system where much of the atmosphere was lost through mass transfer to the companion. [1]

Related Research Articles

<span class="mw-page-title-main">Supernova</span> Astrophysical phenomenon

A supernova is a powerful and luminous explosion of a star. A supernova occurs during the last evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion. The original object, called the progenitor, either collapses to a neutron star or black hole, or is completely destroyed to form a diffuse nebula. The peak optical luminosity of a supernova can be comparable to that of an entire galaxy before fading over several weeks or months.

<span class="mw-page-title-main">Superluminous supernova</span> Supernova at least ten times more luminous than a standard supernova

A super-luminous supernova is a type of stellar explosion with a luminosity 10 or more times higher than that of standard supernovae. Like supernovae, SLSNe seem to be produced by several mechanisms, which is readily revealed by their light-curves and spectra. There are multiple models for what conditions may produce an SLSN, including core collapse in particularly massive stars, millisecond magnetars, interaction with circumstellar material, or pair-instability supernovae.

<span class="mw-page-title-main">NGC 300</span> Galaxy in the constellation Sculptor

NGC 300 (also known as Baldwell 70 or the Sculptor Pinwheel Galaxy) is a spiral galaxy in the constellation Sculptor. It was discovered on 5 August 1826 by Scottish astronomer James Dunlop. It is one of the closest galaxies to the Local Group, and it most likely lies between the latter and the Sculptor Group. It is the brightest of the five main spirals in the direction of the Sculptor Group. It is inclined at an angle of 42° when viewed from Earth and shares many characteristics of the Triangulum Galaxy. It is 94,000 light-years in diameter, somewhat smaller than the Milky Way, and has an estimated mass of (2.9 ± 0.2) × 1010M.

<span class="mw-page-title-main">SN 2005df</span> 2005 supernova event in the constellation Reticulum

SN 2005df was a Type Ia supernova in the barred spiral galaxy NGC 1559, which is located in the southern constellation of Reticulum. The event was discovered in Australia by Robert Evans on the early morning of August 5, 2005 with a 13.8 magnitude, and was confirmed by A. Gilmore on August 6. The supernova was classified as Type Ia by M. Salvo and associates. It was positioned at an offset of 15.0″ east and 40.0″ north of the galaxy's nucleus, reaching a maximum brightness of 12.3 on August 18. The supernova luminosity appeared unreddened by dust from its host galaxy.

<span class="mw-page-title-main">NGC 2997</span> Galaxy in the constellation Antlia

NGC 2997 is a face-on unbarred spiral galaxy about 40 million light-years away in the faint southern constellation of Antlia. It was discovered March 4, 1793 by German-born astronomer William Herschel. J. L. E. Dreyer described it as, "a remarkable object, very faint, very large, very gradually then very suddenly bright middle and 4 arcsec nucleus. This is the brightest galaxy of the NGC 2997 group of galaxies, and was featured on the cover of the first edition of Galactic Dynamics by James Binney and Scott Tremaine.

<span class="mw-page-title-main">Type Ib and Ic supernovae</span> Types of supernovae caused by a star collapsing

Type Ib and Type Ic supernovae are categories of supernovae that are caused by the stellar core collapse of massive stars. These stars have shed or been stripped of their outer envelope of hydrogen, and, when compared to the spectrum of Type Ia supernovae, they lack the absorption line of silicon. Compared to Type Ib, Type Ic supernovae are hypothesized to have lost more of their initial envelope, including most of their helium. The two types are usually referred to as stripped core-collapse supernovae.

<span class="mw-page-title-main">NGC 4603</span> Galaxy in the constellation Centaurus

NGC 4603 is a spiral galaxy located about 107 million light years away in the constellation Centaurus. It is a member of the Centaurus Cluster of galaxies, belonging to the section designated "Cen30". The morphological classification is SA(s)c, which indicates it is a pure spiral galaxy with relatively loosely wound arms.

<span class="mw-page-title-main">NGC 5371</span> Galaxy in constellation Canes Venatici

NGC 5371 is a face-on spiral galaxy in the northern constellation Canes Venatici. It was discovered on January 14, 1788 by German-British astronomer William Herschel. The nearby NGC 5390 appears to be a duplicate entry for NGC 5371, since there is nothing at the former's position. NGC 5371 has an apparent magnitude of 11.3 and an angular size of 4.4′ × 3.5′. It is located at a distance of 129.5 ± 32.4 million light-years (39.70 ± 9.92 Mpc) from the Milky Way, and is receding with a heliocentric radial velocity of 2,552 km/s. The galaxy appears to be weakly interacting with the nearby, equidistant Hickson 68 group of galaxies, and thus may be a member. Collectively, they are sometimes dubbed the Big Lick galaxy group, after the city of Roanoke, Virginia.

SN 2007sr was a Type Ia supernova event that happened in the galaxy NGC 4038. It was announced on December 18, 2007, but was visible on images beginning December 7. It peaked at magnitude 12.7 on December 14.

<span class="mw-page-title-main">NGC 2770</span> Spiral galaxy in the constellation Lynx

NGC 2770 is a spiral galaxy in the northern constellation of Lynx, near the northern constellation border with Cancer. It was discovered by German-born astronomer William Herschel on December 7, 1785. J. L. E. Dreyer described it as, "faint, large, much extended 150°, mottled but not resolved, 2 stars to north". NGC 2770 was the target for the first binocular image produced by the Large Binocular Telescope.

SN 2007uy was a supernova that occurred in the spiral galaxy NGC 2770. It was discovered by Yoji Hirose on December 31, 2007 from Chigasaki city in Japan, approximately four days after the explosion. The position of the supernova was offset 20.6″ east and 15.5″ south of the galaxy's nucleus, near a star-forming region. It was identified as a Type Ib supernova from its spectrum a week before reaching maximum, and appeared the most similar to SN 2004gq.

<span class="mw-page-title-main">Supernova impostor</span> Stellar explosions that appear to be supernovae

Supernova impostors are stellar explosions that appear at first to be a supernova but do not destroy their progenitor stars. As such, they are a class of extra-powerful novae. They are also known as Type V supernovae, Eta Carinae analogs, and giant eruptions of luminous blue variables (LBV).

<span class="mw-page-title-main">SN 1998aq</span> Supernova in the constellation Ursa Major

SN 1998aq is a nearby supernova located in the intermediate spiral galaxy NGC 3982, offset 18″ west and 7″ of the galactic nucleus. It was discovered April 13, 1998 by amateur astronomer Mark Armstrong and was confirmed by fellow British amateur Ron Arbour; both members of the U.K. Supernova/Nova Patrol. The event was not visible on a prior check by Armstrong made April 7. It reached peak brightness on April 27, and 15 days later had declined by 1.14 magnitudes in the B (blue) band.

<span class="mw-page-title-main">NGC 5806</span> Spiral galaxy in the constellation Virgo

NGC 5806 is an intermediate spiral galaxy in the constellation Virgo. It was discovered on February 24, 1786, by the astronomer John Herschel. It is located about 70 million light-years away from the Milky Way. It is a member of the NGC 5846 Group.

<span class="mw-page-title-main">NGC 6384</span> Galaxy in the constellation of Ophiucus

NGC 6384 is an intermediate barred spiral galaxy located about 77 million light-years away in the northern part of the constellation Ophiuchus. It was discovered on 10 June 1863 by German-British astronomer Albert Marth.

<span class="mw-page-title-main">NGC 613</span> Galaxy in the constellation of Sculptor

NGC 613 is a barred spiral galaxy located 67 million light years away in the southern constellation of Sculptor. This galaxy was discovered in 1798 by German-English astronomer William Herschel, then re-discovered and catalogued by Scottish astronomer James Dunlop. It was first photographed in 1912, which revealed the spiral form of the nebula. During the twentieth century, radio telescope observations showed that a linear feature in the nucleus was a relatively strong source of radio emission.

<span class="mw-page-title-main">NGC 4424</span> Spiral galaxy in the constellation Virgo

NGC 4424 is a spiral galaxy located in the equatorial constellation of Virgo. It was discovered February 27, 1865 by German astronomer Heinrich Louis d'Arrest. This galaxy is located at a distance of 13.5 million light years and is receding with a heliocentric radial velocity of 442 km/s. It has a morphological class of SB(s)a, which normally indicates a spiral galaxy with a barred structure (SB), no inner ring feature (s), and tightly-wound spiral arms (a). The galactic plane is inclined at an angle of 62° to the line of sight from the Earth. It is a likely member of the Virgo Cluster of galaxies.

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<span class="mw-page-title-main">NGC 6951</span> Galaxy in the constellation Cepheus

NGC 6951 is a barred spiral galaxy located in the constellation Cepheus. It is located at a distance of about 75 million light-years from Earth, which, given its apparent dimensions, means that NGC 6951 is about 100,000 light-years across. It was discovered by Jérôme Eugène Coggia in 1877 and independently by Lewis Swift in 1878.

References

  1. 1 2 Folatelli, Gastón; et al. (October 2015). "The Progenitor of the Type IIb SN 2008ax Revisited". The Astrophysical Journal. 811 (2): 13. arXiv: 1509.01588 . Bibcode:2015ApJ...811..147F. doi:10.1088/0004-637X/811/2/147. S2CID   53463754. 147.
  2. 1 2 3 Drake, A. J.; et al. (May 2009). "First Results from the Catalina Real-Time Transient Survey". The Astrophysical Journal. 696 (1): 870–884. arXiv: 0809.1394 . Bibcode:2009ApJ...696..870D. doi:10.1088/0004-637X/696/1/870. S2CID   7530040.
  3. 1 2 3 4 Pastorello, A.; et al. (September 2008). "The Type IIb SN 2008ax: spectral and light curve evolution". Monthly Notices of the Royal Astronomical Society. 389 (2): 955–966. arXiv: 0805.1914 . Bibcode:2008MNRAS.389..955P. doi: 10.1111/j.1365-2966.2008.13618.x . S2CID   16483475.
  4. David Bishop. "Supernova 2008ax in NGC 4490". supernovae.net (International Supernovae Network). Archived from the original on 8 April 2010. Retrieved 7 June 2010.
  5. Mostardi, R.; et al. (March 2008). Green, D. W. E. (ed.). "Possible Supernova in NGC 4490". Central Bureau Electronic Telegrams. 1280 (1): 1. Bibcode:2008CBET.1280....1M.
  6. Nakano, S. (March 2008). Green, D. W. E. (ed.). "Supernova 2008ax in NGC 4490". Central Bureau Electronic Telegrams. 1286 (1): 1. Bibcode:2008CBET.1286....1N.
  7. David Bishop. "Bright Supernovae - 2008". supernovae.net (International Supernovae Network). Archived from the original on 27 September 2011. Retrieved 7 June 2010.
  8. Roming, P. W. A.; et al. (October 2009). "Multi-Wavelength Properties of the Type IIb SN 2008ax". The Astrophysical Journal Letters. 704 (2): L118–L123. arXiv: 0909.0967 . Bibcode:2009ApJ...704L.118R. doi:10.1088/0004-637X/704/2/L118. S2CID   51315301.