IPTF14hls

Last updated
iPTF14hls
IPTF14hls.png
Supernova iPTF14hls before and after detection
Observation data
Epoch J2000 [1]        Equinox
Constellation Ursa Major
Right ascension 09h 20m 34.30s [1]
Declination +50° 41′ 46.80″ [1]
Apparent magnitude  (V)17.716 (R) [1]
Astrometry
Distance 156,200,000  pc (509,000,000  ly) [1]   pc
Database references
SIMBAD data

iPTF14hls is an unusual supernova star that erupted continuously for about 1,000 days beginning in September 2014 [2] before becoming a remnant nebula. [3] It had previously erupted in 1954. [4] None of the theories nor proposed hypotheses fully explain all the aspects of the object.

Contents

Observations

The star iPTF14hls was discovered in September 2014 by the Intermediate Palomar Transient Factory, [5] and it was first made public in November 2014 by the CRTS survey [6] as CSS141118:092034+504148. [7] Based on that information, it was confirmed as an exploding star in January 2015. [8] [4] It was thought then that it was a single supernova event (Type II-P) that would dim in about 100 days, but instead, it continued its eruption for about 1,000 days [3] while fluctuating in brightness at least five times. [1] The brightness varied by as much as 50%, [4] going through five peaks. [5] Also, rather than cooling down with time as expected of a Type II-P supernova, the object maintains a near-constant temperature of about 5000–6000 K. [1] Checks of photographs from the past found one from 1954 showing an explosion in the same location. [4] Since 1954, the star has exploded six times. [9]

The principal investigator [10] is Iair Arcavi. His international team used the Low-Resolution Imaging Spectrometer (LRIS) on the Keck I telescope to obtain the spectrum of the star's host galaxy, and the Deep Imaging and Multi-Object Spectrograph (DEIMOS) on Keck II to obtain high-resolution spectra of the unusual supernova itself. [11]

The host galaxy of iPTF14hls is a star-forming dwarf galaxy, implying low metal content, and the weak iron-line absorption seen in the supernova spectra are consistent with a low metallicity progenitor. [1] The study estimates that the star that exploded was at least 50 times more massive than the Sun. [12] The researchers also remark that the debris expansion rate is slower than any other known supernova by a factor of 6, as if exploding in slow motion. However, if this were due to relativistic time dilation, then the spectrum would be red-shifted by the same factor of 6, which is inconsistent with their observations. [1] In 2017, the expansion speed was constrained to approximately 1,000  km/s . [13] [14]

Ongoing observations

Arcavi's team continue monitoring the object in other bands of the spectrum in collaboration with additional international telescopes and observatories. [15] These facilities include the Nordic Optical Telescope and NASA's Swift space telescope, the Fermi Gamma-ray Space Telescope, [16] while the Hubble Space Telescope began to image the location in December 2017. [15] [17]

iPTF14hls was an ongoing event into 2018, when after about 1,000 days, its light displayed a dramatic drop, but the event remained visible, [3] and by November 2018 its spectra had become a remnant nebula. [3] A high-resolution image of this latest phase was obtained with the Hubble Space Telescope during Cycle 25 (October 1, 2017 to September 30, 2018). [3]

Hypotheses

Current theory predicts that the star would consume all its hydrogen in the first supernova explosion and, depending on the initial size of the star, the remnants of the core should form a neutron star or a black hole. [1] [5] [4] However, these mechanisms are unable to reproduce the observed light curve with its very long bright plateau and multiple brighter peaks. [17] [18] None of the hypotheses published before early 2018 — the first three listed below — could explain the continued presence of hydrogen or the energetics observed. [19] [20] According to Iair Arcavi, this discovery requires refinement of existing explosion scenarios, or the development of a new scenario, that can: [1]

  1. produce the same spectral signatures as common Type IIP supernovae but with an evolution slowed by a factor of 6 to 10.
  2. provide energy to prolong the light curve by a factor of ~6 while not introducing narrow-line spectral features or strong radio and X-ray emission indicative of circumstellar material interaction.
  3. produce at least five peaks in the light curve.
  4. decouple the deduced line-forming photosphere from the continuum photosphere.
  5. maintain a photospheric phase with a constant line velocity gradient for over 600 days.

Antimatter

One hypothesis involves burning antimatter in a stellar core; [5] this hypothesis holds that massive stars become so hot in their cores that energy is converted into matter and antimatter, causing the star to become extremely unstable, and undergo repeated bright eruptions over periods of years. [21] Antimatter in contact with matter would cause an explosion that blows off the outer layers of the star and leaves the core intact; this process can repeat over decades before the large final explosion and collapse to a black hole. [12]

Pulsational pair-instability supernova

Another hypothesis is the pulsational pair-instability supernova, a massive star that may lose about half its mass before a series of violent pulses begins. [1] [19] On every pulse, material rushing away from the star can catch up with earlier ejected material, producing bright flashes of light as it collides, simulating an additional explosion (see supernova impostor). However, the energy released by the iPTF14hls supernova is more than the theory predicts. [12]

Magnetar

Magnetar models can also explain many of the observed features, but give a smooth light curve and may require an evolving magnetic field strength. [20] [22]

Shock interaction

Jennifer E Andrews and Nathan Smith hypothesised that the observed light spectrum is a clear signature of shock interaction of ejected material with dense circumstellar material (CSM). They proposed that a typical explosion energy, with "enveloped" or "swallowed" CSM interaction — as seen in some recent supernovae, including SN 1998S, SN 2009ip, and SN 1993J — could "explain the peculiar evolution of iPTF14hls." [23]

In December 2017, a team using the Fermi Gamma-ray Space Telescope reported that they may have detected in iPTF14hls, for the first time, high energy gamma-ray emission from a supernova. [16] The gamma-ray source appears ~ 300 days after the explosion of iPTF14hls, and is still observable, but more observations are needed to verify that iPTF14hls is the exact source of the observed gamma-ray emission. [16] If the association between the gamma-ray source and iPTF14hls is real, there are difficulties to model its gamma-ray emission in the framework of particle acceleration in supernova ejecta produced shock. The energy conversion efficiency needs to be very high, so it is suggested that a jet (anisotropic emission) from a close companion may be necessary to explain some of the observed data. [16] No X-ray emissions have been detected, which makes the interpretation of the gamma-ray emission a difficult task. [24]

Common envelope jets

This hypothesis suggests common envelope jets supernova (CEJSN) impostors resulting from a neutron star companion. It proposes "a new type of repeating transient outburst initiated by a neutron star entering the envelope of an evolved massive star, accreting envelope material and subsequently launching jets which interact with their surroundings." [25] [26] The ejecta could reach velocities of 10,000 km/s despite not being a supernova. [25]

Fall-back accretion

One team suggests the possibility that the observed slow expansion may be an effect of fall-back accretion, and presented a model. [3] [27]

Variable hyper-wind

A long-term outflow similar to stellar winds with variable mass-loss rates rather than a sudden outburst like supernovae could fit the data of the light curve not only of iPTF14hls, but also of Eta Carinae. The observations could be a result of extreme wind from very massive stars. [28]

See also

Related Research Articles

<span class="mw-page-title-main">Supernova</span> Explosion of a star at its end of life

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">SN 1987A</span> 1987 supernova event in the constellation Dorado

SN 1987A was a type II supernova in the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way. It occurred approximately 51.4 kiloparsecs from Earth and was the closest observed supernova since Kepler's Supernova in 1604. Light and neutrinos from the explosion reached Earth on February 23, 1987 and was designated "SN 1987A" as the first supernova discovered that year. Its brightness peaked in May of that year, with an apparent magnitude of about 3.

<span class="mw-page-title-main">Gamma-ray burst</span> Flashes of gamma rays from distant galaxies

In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies, being the brightest and most extreme explosive events in the entire universe, as NASA describes the bursts as the "most powerful class of explosions in the universe". They are the most energetic and luminous electromagnetic events since the Big Bang. Gamma-ray bursts can last from ten milliseconds to several hours. After the initial flash of gamma rays, an "afterglow" is emitted, which is longer lived and usually emitted at longer wavelengths.

<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">Messier 108</span> Galaxy in the constellation Ursa Major

Messier 108 is a barred spiral galaxy about 28 million light-years away from Earth in the northern constellation Ursa Major. It was discovered by Pierre Méchain in 1781 or 1782. From the Earth, this galaxy is seen almost edge-on.

<span class="mw-page-title-main">NGC 6946</span> Galaxy in the constellations Cepheus & Cygnus

NGC 6946, sometimes referred to as the Fireworks Galaxy, is a face-on intermediate spiral galaxy with a small bright nucleus, whose location in the sky straddles the boundary between the northern constellations of Cepheus and Cygnus. Its distance from Earth is about 25.2 million light-years or 7.72 megaparsecs, similar to the distance of M101 in the constellation Ursa Major. Both were once considered to be part of the Local Group, but are now known to be among the dozen bright spiral galaxies near the Milky Way but beyond the confines of the Local Group. NGC 6946 lies within the Virgo Supercluster.

<span class="mw-page-title-main">Type Ia supernova</span> Type of supernova in binary systems

A Type Ia supernova is a type of supernova that occurs in binary systems in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white dwarf.

<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">Type II supernova</span> Explosion of a star 8 to 45 times the mass of the Sun

A Type II supernova or SNII results from the rapid collapse and violent explosion of a massive star. A star must have at least eight times, but no more than 40 to 50 times, the mass of the Sun (M☉) to undergo this type of explosion. Type II supernovae are distinguished from other types of supernovae by the presence of hydrogen in their spectra. They are usually observed in the spiral arms of galaxies and in H II regions, but not in elliptical galaxies; those are generally composed of older, low-mass stars, with few of the young, very massive stars necessary to cause a supernova.

<span class="mw-page-title-main">Pair-instability supernova</span> Type of high-energy supernova in very large stars

A pair-instability supernova is a type of supernova predicted to occur when pair production, the production of free electrons and positrons in the collision between atomic nuclei and energetic gamma rays, temporarily reduces the internal radiation pressure supporting a supermassive star's core against gravitational collapse. This pressure drop leads to a partial collapse, which in turn causes greatly accelerated burning in a runaway thermonuclear explosion, resulting in the star being blown completely apart without leaving a stellar remnant behind.

<span class="mw-page-title-main">Gamma-ray burst progenitors</span> Types of celestial objects that can emit gamma-ray bursts

Gamma-ray burst progenitors are the types of celestial objects that can emit gamma-ray bursts (GRBs). GRBs show an extraordinary degree of diversity. They can last anywhere from a fraction of a second to many minutes. Bursts could have a single profile or oscillate wildly up and down in intensity, and their spectra are highly variable unlike other objects in space. The near complete lack of observational constraint led to a profusion of theories, including evaporating black holes, magnetic flares on white dwarfs, accretion of matter onto neutron stars, antimatter accretion, supernovae, hypernovae, and rapid extraction of rotational energy from supermassive black holes, among others.

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

SN 1998S was a type IIn supernova that was detected in NGC 3877 in March 1998. At the time of discovery, SN 1998S was the brightest type IIn event observed, although later outshone by SN 2010jl.

<span class="mw-page-title-main">NGC 7424</span> Galaxy in the constellation Grus

NGC 7424 is a barred spiral galaxy located 37.5 million light-years away in the southern constellation Grus. Its size makes it similar to our own galaxy, the Milky Way. It is called a "grand design" galaxy because of its well defined spiral arms. Two supernovae and two ultraluminous X-ray sources have been discovered in NGC 7424.

<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.

A failed supernova is an astronomical event in time domain astronomy in which a star suddenly brightens as in the early stage of a supernova, but then does not increase to the massive flux of a supernova. They could be counted as a subcategory of supernova imposters. They have sometimes misleadingly been called unnovae.

<span class="mw-page-title-main">Hypernova</span> Supernova that ejects a large mass at unusually high velocity

A hypernova is a very energetic supernova which is believed to result from an extreme core collapse scenario. In this case, a massive star collapses to form a rotating black hole emitting twin astrophysical jets and surrounded by an accretion disk. It is a type of stellar explosion that ejects material with an unusually high kinetic energy, an order of magnitude higher than most supernovae, with a luminosity at least 10 times greater. Hypernovae release such intense gamma rays that they often appear similar to a type Ic supernova, but with unusually broad spectral lines indicating an extremely high expansion velocity. Hypernovae are one of the mechanisms for producing long gamma ray bursts (GRBs), which range from 2 seconds to over a minute in duration. They have also been referred to as superluminous supernovae, though that classification also includes other types of extremely luminous stellar explosions that have different origins.

SN 2013fs is a supernova, located in the spiral galaxy NGC 7610, discovered by the Intermediate Palomar Transient Factory sky survey at Palomar Observatory in October 2013. It was discovered approximately three hours from explosion and was observed in ultraviolet and X-ray wavelengths, among others, within several hours. Optical spectra were obtained beginning at six hours from explosion, making these the earliest such detailed observations ever made of a supernova.

<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.

<span class="mw-page-title-main">SN 2018cow</span> Supernova event of June 2018 in the constellation Hercules

SN 2018cow was a very powerful astronomical explosion, 10–100 times brighter than a normal supernova, spatially coincident with galaxy CGCG 137-068, approximately 200 million ly (60 million pc) distant in the Hercules constellation. It was discovered on 16 June 2018 by the ATLAS-HKO telescope, and had generated significant interest among astronomers throughout the world. Later, on 10 July 2018, and after AT 2018cow had significantly faded, astronomers, based on follow-up studies with the Nordic Optical Telescope (NOT), formally described AT 2018cow as SN 2018cow, a type Ib supernova, showing an "unprecedented spectrum for a supernova of this class"; although others, mostly at first but also more recently, have referred to it as a type Ic-BL supernova. An explanation to help better understand the unique features of AT 2018cow has been presented. AT2018cow is one of the few reported Fast Blue Optical Transients (FBOTs) observed in the Universe. In May 2020, however, a much more powerful FBOT than AT 2018cow was reportedly observed.

<span class="mw-page-title-main">SN 2020oi</span> Extragalactic supernova in 2020

SN 2020oi was a supernova event in the grand design spiral galaxy known as Messier 100, or NGC 4321. It was discovered January 7, 2020 at an apparent magnitude of 17.28 by F. Forster and associates using the Zwicky Transient Facility. The position places it ~4.67″ north of the galactic nucleus. The supernova was not detected on an observation made three days before the discovery, and thus it must have begun during that brief period. The light curve peaked around January 13–18, depending on the wavelength, then declined rapidly over a period of 25 days before flattening into a more gradual decline. Observations of the spectrum made with the SOAR telescope showed this to be a type Ic supernova, with the progenitor being a massive star that had its outer envelope stripped. The initial velocity of the expanding photosphere was ~15,000 km/s.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 Arcavi, Iair; et al. (2017). "Energetic eruptions leading to a peculiar hydrogen-rich explosion of a massive star" (PDF). Nature. 551 (7679): 210–213. arXiv: 1711.02671 . Bibcode:2017Natur.551..210A. doi:10.1038/nature24030. PMID   29120417. S2CID   205260551.
  2. ↑ Tasoff, H. (9 November 2017). "Bizarre Supernova Defies Understanding". Scientific American. Retrieved 2010-08-20.
  3. 1 2 3 4 5 6 Sollerman, J.; Taddia, F.; Arcavi, I.; Fremling, C.; Fransson, C.; Burke, J.; Cenko, S. B.; Andersen, O.; Andreoni, I.; Barbarino, C.; Blagorodova, N.; Brink, T. G.; Filippenko, A. V.; Gal-Yam, A.; Hiramatsu, D.; Hosseinzadeh, G.; Howell, D. A.; De Jaeger, T.; Lunnan, R.; McCully, C.; Perley, D. A.; Tartaglia, L.; Terreran, G.; Valenti, S.; Wang, X. (2019). "Late-time observations of the extraordinary Type II supernova iPTF14hls". Astronomy and Astrophysics. 621: A30. arXiv: 1806.10001 . Bibcode:2019A&A...621A..30S. doi:10.1051/0004-6361/201833689. S2CID   119218055.
  4. 1 2 3 4 5 Paul Rincon (8 November 2017). "'Zombie' star survived going supernova". BBC News. Retrieved 2019-11-11.
  5. 1 2 3 4 Lisa Grossman (2017-11-07). "This star cheated death, exploding again and again". Science News. Retrieved 2019-11-11.
  6. ↑ "The CRTS Survey". crts.caltech.edu. Retrieved 2017-11-15.
  7. ↑ "Detection of CSS141118:092034+504148" . Retrieved 2019-11-11.
  8. ↑ Li, Wenxiong; Wang, Xiaofeng; Zhang, Tianmeng (2015-01-01). "Spectroscopic Classification of CSS141118:092034+504148 as a Type II-P Supernova". The Astronomer's Telegram. 6898: 1. Bibcode:2015ATel.6898....1L.
  9. ↑ Joel Hruska (2017-11-10). "Astronomers Find Star That Has Exploded Six Times". Extremetech. Retrieved 2017-11-26.
  10. ↑ Arcavi, I.; et al. (2017). "Supplementary Information to Arcavi, Iair; et al. (2017)" (PDF). Nature. 551 (7679): 210–213. arXiv: 1711.02671 . Bibcode:2017Natur.551..210A. doi:10.1038/nature24030. PMID   29120417. S2CID   205260551.
  11. ↑ "Astronomers Discover A Star That Would Not Die". W. M. Keck Observatory. 2017-11-08. Archived from the original on 2018-05-17. Retrieved 2019-11-11.
  12. 1 2 3 "Astronomers discover a star that would not die". Astronomy Now. 2017-11-07. Retrieved 2019-11-11.
  13. ↑ Milisavljevic, Dan; Margutti, Raffaella (2018). "Peculiar Supernovae". Space Science Reviews. 214 (4): 68. arXiv: 1805.03655 . Bibcode:2018SSRv..214...68M. doi:10.1007/s11214-018-0500-y. S2CID   118946200.
  14. ↑ Andrews, Jennifer E.; Smith, Nathan (2018). "Strong late-time circumstellar interaction in the peculiar supernova iPTF14hls". Monthly Notices of the Royal Astronomical Society. 477 (1): 74. arXiv: 1712.00514 . Bibcode:2018MNRAS.477...74A. doi: 10.1093/mnras/sty584 . S2CID   119254457.
  15. 1 2 Harrison Tasoff (2017-11-08). "Bizarre 3-Year-Long Supernova Defies Our Understanding of How Stars Die". Space. Retrieved 2019-11-11.
  16. 1 2 3 4 Yuan, Qiang; Liao, Neng-Hui; Xin, Yu-Liang; Li, Ye; Fan, Yi-Zhong; Zhang, Bing; Hu, Hong-Bo; Bi, Xiao-Jun (2018). "Fermi Large Area Telescope Detection of Gamma-Ray Emission from the Direction of Supernova iPTF14hls". The Astrophysical Journal. 854 (2): L18. arXiv: 1712.01043 . Bibcode:2018ApJ...854L..18Y. doi: 10.3847/2041-8213/aaacc9 . S2CID   59932302.
  17. 1 2 Arcavi, Iair (2017). "What Type of Star Made the One-of-a-kind Supernova iPTF14hls?". HST Proposal: 15222. Bibcode:2017hst..prop15222A.
  18. ↑ John Timmer (2017-11-08). "Scientists on new supernova: WTF have we been looking at?". Ars Technica. Retrieved 2019-11-11.
  19. 1 2 Ian Sample (2017-11-08). "'Zombie star' amazes astronomers by surviving multiple supernovae". The Guardian. Retrieved 2019-11-11.
  20. 1 2 Woosley, S. E. (2018). "Models for the Unusual Supernova iPTF14hls". The Astrophysical Journal. 863 (1): 105. arXiv: 1801.08666 . Bibcode:2018ApJ...863..105W. doi: 10.3847/1538-4357/aad044 . S2CID   119412234.
  21. ↑ Jake Parks (2017-11-09). "This Star Went Supernova … And Then Went Supernova Again". Discovery Magazine. Archived from the original on 2018-05-31. Retrieved 2019-11-11.
  22. ↑ Dessart, Luc (2018). "A magnetar model for the hydrogen-rich super-luminous supernova iPTF14hls". Astronomy & Astrophysics. 610: L10. arXiv: 1801.05340 . Bibcode:2018A&A...610L..10D. doi:10.1051/0004-6361/201732402. S2CID   119073998.
  23. ↑ Andrews, Jennifer E.; Smith, Nathan (2018). "Strong late-time circumstellar interaction in the peculiar supernova iPTF14hls". Monthly Notices of the Royal Astronomical Society. 477 (1): 74–79. arXiv: 1712.00514 . Bibcode:2018MNRAS.477...74A. doi: 10.1093/mnras/sty584 . S2CID   119254457.
  24. ↑ Yuan, Qiang; Liao, Neng-Hui; Xin, Yu-Liang; Li, Ye; Fan, Yi-Zhong; Zhang, Bing; Hu, Hong-Bo; Bi, Xiao-Jun (2018). "Fermi Large Area Telescope Detection of Gamma-Ray Emission from the Direction of Supernova iPTF14hls". The Astrophysical Journal. 854 (2): L18. arXiv: 1712.01043 . Bibcode:2018ApJ...854L..18Y. doi: 10.3847/2041-8213/aaacc9 . S2CID   59932302.
  25. 1 2 Gilkis, Avishai; Soker, Noam; Kashi, Amit (2019). "Common envelope jets supernova (CEJSN) impostors resulting from a neutron star companion". Monthly Notices of the Royal Astronomical Society. 482 (3): 4233. arXiv: 1802.08669 . Bibcode:2019MNRAS.482.4233G. doi: 10.1093/mnras/sty3008 . S2CID   119400775.
  26. ↑ Soker, Noam; Gilkis, Avishai (2018). "Explaining iPTF14hls as a common-envelope jets supernova". Monthly Notices of the Royal Astronomical Society. 475 (1): 1198. arXiv: 1711.05180 . Bibcode:2018MNRAS.475.1198S. doi: 10.1093/mnras/stx3287 . S2CID   59330952.
  27. ↑ Wang, L. J.; Wang, X. F.; Wang, S. Q.; Dai, Z. G.; Liu, L. D.; Song, L. M.; Rui, L. M.; Cano, Z.; Li, B. (2018). "A Fallback Accretion Model for the Unusual Type II-P Supernova iPTF14hls". The Astrophysical Journal. 865 (2): 95. arXiv: 1802.03982 . Bibcode:2018ApJ...865...95W. doi: 10.3847/1538-4357/aadba4 . S2CID   118940781.
  28. ↑ Moriya, Takashi J.; Mazzali, Paolo A.; Pian, Elena (2020). "iPTF14hls as a variable hyper-wind from a very massive star". Monthly Notices of the Royal Astronomical Society. 491 (1). arXiv: 1911.01740 . doi: 10.1093/mnras/stz3122 .
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