Tabby's Star

Coordinates: Sky map 20h 06m 15.457s, +44° 27′ 24.61″
Source: Wikipedia, the free encyclopedia.
Tabby's Star

Tabby's Star in infrared (left) and ultraviolet (right)
Observation data
ICRS
)
Constellation Cygnus
Right ascension 20h 06m 15.45265s[1]
Declination +44° 27′ 24.7909″[1]
Apparent magnitude (V) +11.705±0.017[2]
Characteristics
KIC 8462852 A
Evolutionary stage Main sequence[2]
Spectral type F3V[2]
B−V color index 0.557
V−R color index 0.349
R−I color index 0.305
J−H color index 0.212
J−K color index 0.264
KIC 8462852 B
Spectral type
M2V[3]
Distance
1,500 ± 100 ly
(450 ± 30 pc)
Position (relative to Tabby's Star)[3]
ComponentKIC 8462852 B
Projected separation
880±10 AU
Details
KIC 8462852 A
Rotational velocity (v sin i)
84±4[2] km/s
KIC 8462852 B
Mass0.44±0.02[3] M☉
Radius0.45±0.02[3] R☉
Temperature3720±70[3] K
Other designations
TYC 3162-665-1, Boyajian's Star, WISE J200615.45+442724.7, KIC 8462852, NSVS 5711291, Gaia DR2 2081900940499099136, 2MASS J20061546+4427248, UCAC4 673-083862, TIC 185336364, APASS 52502626
Database references
SIMBADdata
B

Tabby's Star (also known as Boyajian's Star and WTF Star, and designated KIC 8462852 in the Kepler Input Catalog) is an F-type main-sequence star in the constellation Cygnus approximately 1,470 light-years (450 parsecs) from Earth. A distant red dwarf companion has been reported, making Tabby's Star a binary stellar system.

Unusual light fluctuations of Tabby's Star, including up to a 22% dimming in brightness, were discovered by

citizen scientists as part of the Planet Hunters project. The discovery was made from data collected by the Kepler space telescope, which observed changes in the brightness of distant stars to detect exoplanets. Several hypotheses have been proposed to explain the star's large irregular changes in brightness, but As of 2024 none fully explain all aspects of the curve. It has been suggested that it is an alien megastructure, but evidence tends to discount this suggestion.[7]

In September 2019, astronomers reported that the observed dimmings of Tabby's Star may have been produced by fragments resulting from the disruption of an orphaned exomoon. Tabby's Star is not the only star that has large irregular dimmings, but other such stars include young stellar objects called YSO dippers, which have different dimming patterns.

Nomenclature

The names "Tabby's Star" and "Boyajian's Star" refer to American astronomer

scientific paper that announced the discovery of the star's irregular light fluctuations in 2015.[8][9] The nickname "WTF Star" is a reference to the paper's subtitle "where's the flux?", which highlights the observed dips in the star's radiative flux.[10][11][12][13] The star has also been given the nickname "LGM-2" – a homage to the first pulsar discovered, PSR B1919+21, which was given the nickname "LGM-1" when it was originally theorized to be a transmission from an extraterrestrial civilization.[14] Other designations in various star catalogues have been given to Tabby's Star. In the Kepler Input Catalog, a collection of astronomical objects catalogued by the Kepler space telescope, Tabby's Star is known as KIC 8462852.[2] In the Tycho-2 Catalogue, an enhanced collection of stars catalogued by Hipparcos, the star is known as TYC 3162-665-1.[2] In the infrared Two Micron All-Sky Survey (2MASS), the star is identified as 2MASS J20061546+4427248.[2]

Location

Map of the constellation Cygnus
Location of Tabby's Star in the constellation Cygnus (circled in red)
upper-left)[15]

Tabby's Star in the constellation Cygnus is roughly halfway between the bright stars Deneb and Delta Cygni as part of the Northern Cross.[16][17] Tabby's Star is situated south of 31 Cygni, and northeast of the star cluster NGC 6866.[17] While only a few arcminutes away from the cluster, it is unrelated and closer to the Sun than it is to the star cluster.

With an apparent magnitude of 11.7, the star cannot be seen by the naked eye, but is visible with a 5-inch (130 mm) telescope[18] in a dark sky with little light pollution.

History of observations

Tabby's Star was observed as early as the year 1890.[19][20][21] The star was cataloged in the Tycho, 2MASS, UCAC4, and WISE astronomical catalogs[22] (published in 1997, 2003, 2009, and 2012, respectively).[23][24][25][26]

The main source of information about the luminosity fluctuations of Tabby's Star is the Kepler space telescope. During its primary and extended mission from 2009 to 2013 it continuously monitored the light curves of over 100,000 stars in a patch of sky in the constellations Cygnus and Lyra.[27]

2017 light fluctuations

Normalized flux for Tabby's Star
2 May 2017 to 4 May 2018: g′
Bruce Gary (HAO)[35][31][36]
Prominent dimmings[28] − start dates (est.):
  • 14 May 2017 ("Elsie"; 2% dip)
  • 11 June ("Celeste"; 2% dip)
  • 2 August ("Skara Brae"; 1% dip)
  • 5 September ("Angkor"; 2.3%;[29] 3%[30] dip)
  • 20 November (unnamed; 1.25%[31] dip)[32]
  • 16 March 2018 ("Caral-Supe"; 1%;[33] 5%[34] dip)
  • 24 March ("Evangeline"; >5% dip)

On 20 May 2017, Boyajian and her colleagues reported, via

Near-InfraRed Optical SETI (NIROSETI), both at Lick Observatory, continue to monitor the star.[38][43][44][45] By the end of the three-day dimming event,[46] a dozen observatories had taken spectra, with some astronomers having dropped their own projects to provide telescope time and resources. More generally the astronomical community was described as having gone "mildly bananas" over the opportunity to collect data in real-time on the unique star.[47] The 2% dip event was named "Elsie" (a homophone of "LC", in reference to Las Cumbres and light curve).[48]

Initial spectra with FRODOSpec at the two-meter

HIRES) and numerous citizen science observatories, acquired spectra of the star,[38][44][45] showing a dimming that had a complex shape, and initially had a pattern similar to the one at 759.75 days from the Kepler event 2, epoch 2 data. Observations were taken across the electromagnetic spectrum
.

Evidence of a second dimming event (named "Celeste")[37] was observed on 13–14 June 2017, which possibly began 11 June, by amateur astronomer Bruce L. Gary.[49] While the light curve on 14–15 June indicated a possible recovery from the dimming event, the dimming continued to increase afterwards,[49] and on 16 June, Boyajian wrote that the event was approaching a 2% dip in brightness.[32][50]

A third prominent 1% dimming event (named "Skara Brae")[37] was detected beginning 2 August 2017,[51][52] and which recovered by 17 August.[32][53]

A fourth prominent dimming event (named "Angkor")[37] began 5 September 2017,[54] and is, as of 16 September 2017, between 2.3%[29] and 3%[30] dimming event, making it the "deepest dip this year".[32][55]

Another dimming event, amounting to a 0.3% dip, began around 21 September 2017 and completely recovered by 4 October 2017.[35]

On 10 October 2017, an increasing brightening, lasting about two weeks, of the starlight from KIC 8462852 was noted by Bruce L. Gary of the Hereford Arizona Observatory[57] and Boyajian.[58] A possible explanation, involving a transiting brown dwarf in a 1,600-day eccentric orbit near KIC 8462852, a "drop feature" in dimness and predicted intervals of brightening, to account for the unusual fluctuating starlight events of KIC 8462852, has been proposed.[57][59][60]

On about 20 November 2017, a fifth prominent dimming event began and had deepened to a depth of 0.44%; as of 16 December 2017, the event recovered, leveled off at dip bottom for 11 days, faded again, to a current total dimming depth of 1.25%, and was recovering again.[57][31]

Dimming and brightening events of the star continue to be monitored; related light curves are updated and released frequently.[33][61]

2018 light fluctuations

The star was too close to the Sun's position in the sky from late December 2017 to mid February 2018 to be seen. Observations resumed in late February.

AAVSO observer John Hall.[65][66] As of 27 March 2018, that second dip was recovering.[67]

2019 light fluctuations

The 2019 observing season began in mid-March, when the star reappeared after its yearly conjunction with the Sun.[68]

The ground based observation campaign was supplemented by the Transiting Exoplanet Survey Satellite (TESS), which observed the star every 2 minutes between 18 July and 11 September 2019.[69][70] It observed a 1.4% dip in brightness between 3–4 September 2019.[71]

Between October 2019 and December 2019, at least seven separate dips were observed, the deepest of which had a depth of 2%. By the end of the observing season in early January 2020, the star had once again recovered in brightness. The total combined depth of the dips in 2019 was 11%, comparable to that seen in 2011 and 2013, but spread over a long time interval.[72] This cluster of dips is roughly centered on the 17 October 2019 date predicted by Sacco et al.[73] for a reappearance, given a 1,574-day (4.31-year) period, of orbiting material comprising the original "D800" dip.

Luminosity

Observations of the luminosity of the star by the Kepler space telescope show small, frequent, non-periodic dips in brightness, along with two large recorded dips in brightness two years apart. The amplitude of the changes in the star's brightness, and the aperiodicity of the changes, mean that this star is of particular interest for astronomers.[74] The star's changes in brightness are consistent with many small masses orbiting the star in "tight formation".[75]

The first major dip, on 5 March 2011, reduced the star's brightness by up to 15%, and the next 726 days later (on 28 February 2013) by up to 22%. (A third dimming, around 8%, occurred 48 days later.) In comparison, a planet the size of Jupiter would only obscure a star of this size by 1%, indicating that whatever is blocking light during the star's major dips is not a planet, but rather something covering up to half the width of the star.[74] Due to the failure of two of Kepler's reaction wheels, the star's predicted 750-day dip around February 2015 was not recorded.[2][76] The light dips do not exhibit an obvious pattern.[77]

In addition to the day-long dimmings, a study of a century's worth of photographic plates suggests that the star has gradually faded in 100 years (from c. 1890 to c. 1990) by about 20%, which would be unprecedented for any F-type main-sequence star.[19][20] Teasing accurate magnitudes from long-term photographic archives is a complex procedure, however, requiring adjustment for equipment changes, and is strongly dependent on the choice of comparison stars. Another study, examining the same photographic plates, concluded that the possible century-long dimming was likely a data artifact, and not a real astrophysical event.[21] Another study from plates between 1895 and 1995 found strong evidence that the star has not dimmed, but kept a constant flux within a few percent, except an 8% dip on 24 October 1978, resulting in a period of the putative occulter of 738 days.[78]

A third study, using light measurements by the Kepler observatory over a four-year period, determined that Tabby's Star dimmed at about 0.34% per year before dimming more rapidly by about 2.5% in 200 days. It then returned to its previous slow fade rate. The same technique was used to study 193 stars in its vicinity and 355 stars similar in size and composition to Tabby's Star. None of these stars exhibited such dimming.[79]

In 2018, a possible 1,574-day (4.31-year) periodicity in dimming of the star was reported.[73]

Stellar companion

A red dwarf stellar companion at projected separation 880±10 AU from Tabby's Star was confirmed to be comoving in 2021.[3][80] For comparison, this is around 180 times the orbit of Jupiter,[81] around 30 times the orbit of Neptune,[82] or around 5.5 times[83] the distance to Voyager 1 as of 2023.

Hypotheses

Originally, and until Kohler's work of 2017, it was thought that, based on the

spectrum and stellar type of Tabby's Star, its changes in brightness could not be attributed to intrinsic variability.[2] Consequently, a few hypotheses have been proposed involving material orbiting the star and blocking its light, although none of these fully fit the observed data.[84]

Some of the proposed explanations involve

interstellar dust, a series of giant planets with very large ring structures,[85][86] a recently captured asteroid field,[2] the system undergoing Late Heavy Bombardment,[87][88] and an artificial megastructure orbiting the star.[89]

By 2018, the leading hypothesis was that the "missing" heat flux involved in the star's dimming could be stored within the star's interior. Such variations in luminosity might arise from a number of mechanisms affecting the efficiency of heat transport inside the star.[90][91]

However, in September 2019, astronomers reported that the observed dimmings of Tabby's Star may have been produced by fragments resulting from the disruption of an orphaned exomoon.[92][93]

Circumstellar dust ring

Artist's concept of an "uneven ring of dust" orbiting Tabby's Star[94][95][96]

Meng et al. (2017) suggested that, based on observational data of Tabby's Star from the

Swift Gamma-Ray Burst Mission, Spitzer Space Telescope, and Belgian AstroLAB IRIS Observatory, only "microscopic fine-dust screens", originating from "circumstellar material", are able to disperse the starlight in the way detected in their measurements.[94][95][96][97] Based on these studies, on 4 October 2017, NASA reported that the unusual dimming events of Tabby's Star are due to an "uneven ring of dust" orbiting the star.[94] Although the explanation of a significant amount of small particles orbiting the star regards "long-term fading" as noted by Meng,[95] the explanation also seems consistent with the week-long fadings found by amateur astronomer Bruce L. Gary and the Tabby Team, coordinated by astronomer Tabetha S. Boyajian, in more recent dimming events.[98][32][35][99][100] A related, but more sophisticated, explanation of dimming events, involving a transiting "brown dwarf" in a 1600-day eccentric orbit near Tabby's Star, a "drop feature" in dimness, and predicted intervals of "brightening", has been proposed.[57][59][60][101] Dimming and brightening events of Tabby's Star continue to be monitored; related light curves are updated and released frequently.[33][102]

Nonetheless, data similar to that observed for Tabby's Star, along with supporting data from the Chandra X-ray Observatory, were found with dust debris orbiting WD 1145+017, a white dwarf that also has unusual light curve fluctuations.[103] Further, the highly variable star RZ Piscium, which brightens and dims erratically, has been found to emit excessive infrared radiation, suggesting that the star is surrounded by large amounts of gas and dust, possibly resulting from the destruction of local planets.[104][105]

A cloud of disintegrating comets

Artist's impression of an orbiting swarm of dusty comet fragments

One proposed explanation for the reduction in light is that it is due to a cloud of disintegrating comets orbiting the star elliptically.[2][87][106][107] This scenario would assume that a planetary system around Tabby's Star has something similar to the Oort cloud and that gravity from a nearby star caused comets from said cloud to fall closer into the system, thereby obstructing the spectra of Tabby's Star. Evidence supporting this hypothesis includes an M-type red dwarf within 132 billion kilometers (885 AU) of Tabby's Star.[2] The notion that disturbed comets from such a cloud could exist in high enough numbers to obscure 22% of the star's observed luminosity has been doubted.[74]

Submillimetre-wavelength observations searching for farther-out cold dust in an asteroid belt akin to the Sun's

Kuiper Belt suggest that a distant "catastrophic" planetary disruption explanation is unlikely; the possibility of a disrupted asteroid belt scattering comets into the inner system is still to be determined.[108]

Younger star with coalescing material around it

Artist's impression of a young star with coalescing material around it

Astronomer Jason T. Wright and others who have studied Tabby's Star have suggested that if the star is younger than its position and speed would suggest, then it may still have coalescing material around it.[10][13][109]

A

0.8–4.2-micrometer spectroscopic study of the system using the NASA Infrared Telescope Facility (NASA IRTF) found no evidence for coalescing material within a few astronomical units of the mature central star.[87][88]

Planetary debris field

Artist's impression of a massive collision with a proto-planet

High-resolution spectroscopy and imaging observations have also been made, as well as spectral energy distribution analyses using the Nordic Optical Telescope in Spain.[2][85] A massive collision scenario would create warm dust that glows in infrared wavelengths, but there is no observed excess infrared energy, ruling out massive planetary collision debris.[74] Other researchers think the planetary debris field explanation is unlikely, given the very low probability that Kepler would ever witness such an event due to the rarity of collisions of such size.[2]

As with the possibility of coalescing material around the star, spectroscopic studies using the NASA IRTF found no evidence for hot close-in dust or circumstellar matter from an evaporating or exploding planet within a few astronomical units of the central star.[87][88] Similarly, a study of past infrared data from NASA's Spitzer Space Telescope and Wide-field Infrared Survey Explorer found no evidence for an excess of infrared emission from the star, which would have been an indicator of warm dust grains that could have come from catastrophic collisions of meteors or planets in the system. This absence of emission supports the hypothesis that a swarm of cold comets on an unusually eccentric orbit could be responsible for the star's unique light curve, but more studies are needed.[87][6]

Consumption of a planet

In December 2016, a team of researchers proposed that Tabby's Star swallowed a planet, causing a temporary and unobserved increase in brightness due to the release of gravitational energy. As the planet fell into its star, it could have been ripped apart or had its moons stripped away, leaving clouds of debris orbiting the star in eccentric orbits. Planetary debris still in orbit around the star would then explain its observed drops in intensity.[110] Additionally, the researchers suggest that the consumed planet could have caused the star to increase in brightness up to 10,000 years ago, and its stellar flux is now returning to the normal state.[110][111]

Large planet with oscillating rings

Sucerquia et al. (2017) suggested that a large planet with oscillating rings may help explain the unusual dimmings associated with Tabby's Star.[112][113]

Large ringed planet followed by Trojan swarms

Ballesteros et al. (2017) proposed a large, ringed planet trailed by a swarm of

semi-major axis of 5.9 AU.[114]

Intrinsic luminosity variations

The reddening observed during the deep dimming events of Tabby's Star is consistent with cooling of its photosphere.[115] It does not require obscuration by dust. Such cooling could be produced by a decreased efficiency of heat transport caused e.g. by decreased effectiveness of convection due to the star's strong differential rotation, or by changes in its modes of heat transport if it is near the transition between radiative and convective heat transport. The "missing" heat flux is stored as a small increase of internal and potential energy.[90]

The possible location of this early F star near the boundary between radiative and convective transport seems to be supported by the finding that the star's observed brightness variations appear to fit the "avalanche statistics" known to occur in a

bifurcation point between two different types of dynamical behavior. Such close-to-critical systems are often observed to exhibit behavior that is intermediate between "order" and "chaos". Three other stars in the Kepler Input Catalog likewise exhibit similar "avalanche statistics" in their brightness variations, and all three are known to be magnetically active. It has been conjectured that stellar magnetism may be involved in Tabby's Star.[117]

An artificial megastructure

Artist's impression of a Dyson swarm

Some astronomers have speculated that the objects eclipsing Tabby's Star could be parts of a

falsifiable hypothesis.[116] Due to extensive media coverage on this matter, Tabby's Star has been compared by Kepler's Steve Howell to KIC 4150611,[121] a star with an odd light curve that was shown, after years of research, to be a part of a five-star system.[122] The likelihood of extraterrestrial intelligence being the cause of the dimming is purely speculative;[100] however, the star remains an outstanding SETI target because natural explanations have yet to fully explain the dimming phenomenon.[10][89] The latest results have ruled out explanations involving only opaque objects such as stars, planets, swarms of asteroids, or alien megastructures.[123]

Exomoons

Two papers published in summer 2019 offered plausible scientific scenarios involving large moons being stripped from their planets. Numeric simulations were performed of the migration of gas giant planets, and their large gaseous moons, during the first few hundred million years after the formation of the planetary system. In approximately 50% of the cases, the results produce a scenario where the moon is freed from its parent planet and its orbit evolves to produce a light curve similar to that of Tabby's Star.[93][124][125][126]

Follow-up studies

As of 2015, numerous

exoplanetology such as the Nancy Grace Roman Space Telescope, TESS, and PLATO.[89][120]

In 2016, a

space dust.[98][32][132]

In December 2018, a search for

laser light emissions from Tabby's Star was carried out using the Automated Planet Finder (APF), which is sensitive enough to detect a 24 MW laser at this distance. Although a number of candidates were identified, further analysis showed that they are coming from the Earth and not from the star.[133]

SETI results

In October 2015, the SETI Institute used the Allen Telescope Array to look for radio emissions from possible intelligent extraterrestrial life in the vicinity of the star.[134][135] After an initial two-week survey, the SETI Institute reported that it found no evidence of technology-related radio signals from the star system.[136][137][138] No narrowband radio signals were found at a level of 180–300 Jy in a 1 Hz channel, or medium-band signals above 10 Jy in a 100 kHz channel.[137]

In 2016, the VERITAS gamma-ray observatory was used to search for ultra-fast optical transients from astronomical objects, with astronomers developing an efficient method sensitive to nanosecond pulses with fluxes as low as about one photon per square meter. This technique was applied on archival observations of Tabby's Star from 2009 to 2015, but no emissions were detected.[139][140]

In May 2017, a related search, based on laser light emissions, was reported, with no evidence found for technology-related signals from Tabby's Star.[141][142]

In September 2017, some

SETI@Home workunits were created based on a previous RF survey of the region around this star.[143]
This was coupled with a doubling in the size of SETI@Home workunits, so the workunits related to this region will probably be the first workunits to have less issues with quantization noise.

EPIC 204278916

Main article: EPIC 204278916

A star called EPIC 204278916,[144][145] as well as some other young stellar objects, have been observed[when?] to exhibit dips with some similarities to those observed in Tabby's Star. They differ in several respects, however. EPIC 204278916 shows much deeper dips than Tabby's Star, and they are grouped over a shorter period, whereas the dips at Tabby's Star are spread out over several years. Furthermore, EPIC 204278916 is surrounded by a proto-stellar disc, whereas Tabby's Star appears to be a normal F-type star displaying no evidence of a disc.[144]

Other stars

An overall study of 21

other similar stars was presented in 2019.[146][147]

Light curve gallery

  • Consolidated plot of major (>= 1%) dimmings (3 April 2021)
    Consolidated plot of major (>= 1%) dimmings (3 April 2021)
  • All light curve data − December 2009 to May 2013, scan days 0066 to 1587 (Kepler)
    All light curve data − December 2009 to May 2013, scan days 0066 to 1587 (Kepler)
  • 5 March 2011 − day 792 15% max dip (Kepler)
    5 March 2011 − day 792
    15% max dip (Kepler)
  • 28 February 2013 − day 1519 22% max dip (Kepler)
    28 February 2013 − day 1519
    22% max dip (Kepler)
  • 17 April 2013 − day 1568 8% max dip (Kepler)
    17 April 2013 − day 1568
    8% max dip (Kepler)
  • One year light curve − up to 4 May 2018 (HAO)[35][31][36]
    One year light curve − up to 4 May 2018 (HAO)[35][31][36]
  • Light curve between 10 October 2019 and 11 January 2020 (HAO)[72]
    Light curve between 10 October 2019 and 11 January 2020 (HAO)[72]

See also

References

  1. ^
    S2CID 244398875
    . Gaia DR3 record for this source at VizieR.
  2. ^
    S2CID 54859232
    .
  3. ^
    S2CID 234354291
    .
  4. S2CID 119308564
    .
  5. ^
    S2CID 244398875
    . Gaia DR3 record for this source at VizieR.
  6. ^
    S2CID 59160168
    .
  7. ^ McKie, Robin (27 April 2024). "'Is it aliens?': how a mysterious star could help the search for extraterrestrial life". The Observer.
  8. ^ Wenz, John (9 February 2016). "NASA's Next Great Telescope Will Settle This Alien Megastructure Mystery For Good". Popular Mechanics. Retrieved 13 February 2016.
  9. ^ Wright, Jason T. (30 August 2016). "What Could Be Going on with Boyajian's Star? Part I". AstroWright. Pennsylvania State University. Retrieved 12 September 2016.
  10. ^ a b c d Wright, Jason T. (15 October 2015). "KIC 8462852: Where's the Flux?". AstroWright. Pennsylvania State University. Retrieved 16 October 2015.
  11. CNN News
    . Retrieved 16 October 2015.
  12. ^ "Discovery of a strange star could mean alien life". Fox News. 15 October 2015. Retrieved 16 October 2015.
  13. ^ a b King, Bob (16 October 2015). "What's Orbiting KIC 8462852 – Shattered Comet or Alien Megastructure?". Universe Today. Retrieved 16 October 2015.
  14. ^ Freeman, David (25 August 2016). "Are Space Aliens Behind The 'Most Mysterious Star In The Universe?'". The Huffington Post. Retrieved 11 December 2016.
  15. Gary, Bruce L. (3 June 2018). "KIC 8462852 Hereford Arizona Observatory Photometry Observations #6". BruceGary.net. Archived from the original
    on 3 June 2018. Retrieved 3 June 2018.
  16. ^ "KIC10 Search Results". Space Telescope Science Institute. Retrieved 16 October 2015.
  17. ^
    ISBN 978-1-931559-31-7
    .
  18. ^ Masi, Gianluca (16 October 2015). "KIC 8462852: A star and its secrets". The Virtual Telescope Project 2.0. Retrieved 22 October 2015.
  19. ^ a b Aron, Jacob (15 January 2016). "Comets can't explain weird 'alien megastructure' star after all". New Scientist. Retrieved 16 January 2016.
  20. ^
    S2CID 118512449
    .
  21. ^
    S2CID 119211276
    .
  22. ^ "TYC 3162-665-1". SIMBAD. Retrieved 17 June 2016.
  23. ^ "Hipparcos". European Space Agency. Retrieved 17 June 2016.
  24. ^ "About 2MASS". California Institute of Technology. Retrieved 17 June 2016.
  25. ^ "USNO CCD Astrograph Catalog (UCAC)". United States Naval Observatory. Archived from the original on 7 February 2016. Retrieved 17 June 2016.
  26. ^ Clavin, Whitney & Harrington, J. D. (14 March 2012). "NASA Releases New WISE Mission Catalog of Entire Infrared Sky". NASA. Retrieved 17 June 2016.
  27. ^ "Kepler: FAQ". NASA. 31 March 2015. Archived from the original on 6 July 2016. Retrieved 17 June 2016.
  28. ^ Boyajian, Tabetha S. (23 April 2018). "2018 data update (14/n)". Where's the Flux?. Retrieved 5 May 2018.
  29. ^ a b Gary, Bruce L. (16 September 2017). "Hereford Arizona Observatory photometry observations of KIC 8462852 between 2 May and 16 September 2017". BruceGary.net. Archived from the original on 17 September 2017. Retrieved 17 September 2017.
  30. ^ a b Boyajian, Tabetha S. (10 September 2017). "Tweets: "Now @tsboyajian's star is down 3%! How low will it go? Hi-res spectra and IR photometry needed!" – Jason T. Wright". Twitter. Archived from the original on 17 September 2017. Retrieved 17 September 2017.
  31. ^
    Gary, Bruce L. (1 January 2018). "Hereford Arizona Observatory photometry observations of KIC 8462852 between 2 May and 31 December 2017". BruceGary.net. Archived from the original
    on 2 January 2018. Retrieved 1 January 2018.
  32. ^
    S2CID 215751718
    .
  33. ^
    Gary, Bruce L. (25 February 2018). "KIC 8462852 Hereford Arizona Observatory Photometry Observations #6"
    . Retrieved 20 March 2018.
  34. ^ a b Boyajian, Tabetha S. (26 March 2018). "2018 March: dip update 7/n". Where's the Flux?. Retrieved 27 March 2018.
  35. ^ a b c d Gary, Bruce L. (4 October 2017). "Hereford Arizona Observatory photometry observations of KIC 8462852 between 2 May and 4 October 2017". BruceGary.net. Archived from the original on 4 October 2017. Retrieved 4 October 2017. Note: g′-band and r′-band dip depths (and shapes) may differ, with g′-band being more sensitive to dust cloud scattering due to its shorter wavelength (0.47 vs. 0.62 micron). For a reasonable particle size distribution (e.g., Hanson, 0.2 micron) the extinction cross section ratio would produce a depth at r′-band that is 0.57 × depth at g′-band. If g′-band depth is 0.3%, for example, depth at r′-band could be 0.17%. The 'Tabby Team' measurements (Fig. 3) at r′-band are compatible with that small dip depth. Incidentally, none of these shapes resemble exo-comet tail transits (as described by Rappaport et al, 2017);[56] so the mystery of what's producing these week-timescale dips continues! Actually, long oval shapes are known to produce V-shaped dips (think of rings with a high inclination).
  36. ^
    Gary, Bruce L. (4 May 2018). "Hereford Arizona Observatory photometry observations of KIC 8462852 between 2 May 2017 and 4 May 2018". BruceGary.net. Archived from the original
    on 5 May 2018. Retrieved 5 May 2018.
  37. ^ a b c d Boyajian, Tabetha S. (18 September 2017). "Dip update 85/n – Welcome Angkor!". Where's the Flux?. Retrieved 18 September 2017.
  38. ^
    Bibcode:2017ATel10405....1B
    . Retrieved 21 May 2017.
  39. ^ Koren, Marina (19 May 2017). "The 'alien megastructure' star is dimming again". The Atlantic. Retrieved 23 May 2017.
  40. ^ Arboleda, Lawrence (20 May 2017). "That 'Alien Megastructure' Star Has Gone Haywire Again And Scientists Are Baffled". The Inquistr.
  41. Science
    . Retrieved 25 May 2017.
  42. ^ Ellis, Tyler (19 May 2017). "WTF has gone into a dip!". Where's the Flux?.
  43. ^
    Bibcode:2017ATel10406....1S
    . Retrieved 21 May 2017.
  44. ^ a b c Wright, Jason T. (19 May 2017). "Tabby's Star is dimming right now (archived video of chat with Jason T. Wright)". YouTube. Retrieved 21 May 2017.
  45. ^ a b c "Mysterious Tabby's Star dims again: Observations needed". The Lined Wolf. WordPress.com. 20 May 2017. Retrieved 21 May 2017.
  46. ^ Cooper, Keith (24 May 2017). "The Galaxy's strangest star dims again". Astronomy Now. Retrieved 25 May 2017.
  47. ^ Kaplan, Sarah (24 May 2017). "The weirdest star in the sky is acting up again". The Washington Post. Speaking of Science.
  48. ^ Boyajian, Tabetha S. (1 June 2017). "Dip update 6/n". Where's the Flux?. Retrieved 4 June 2017.
  49. ^ a b Gary, Bruce L. (21 June 2017). "Kepler star KIC 8462852 Amateur Photometry Monitoring Project". BruceGary.net. Archived from the original on 21 June 2017.
  50. ^ Boyajian, Tabetha S. [@tsboyajian] (16 June 2017). "#TabbysStar is approaching 2% dim – Who will observe tonight?!!" (Tweet). Retrieved 17 June 2017 – via Twitter.
  51. ^ Boyajian, Tabetha S. (2 August 2017). "Dip update 47/n". Where's the Flux?. Retrieved 11 August 2017.
  52. ^ Boyajian, Tabetha S. (10 August 2017). "Dip update 54/n". Where's the Flux?. Retrieved 11 August 2017.
  53. ^ Gary, Bruce L. (18 August 2017). "Hereford Arizona Observatory photometry observations of KIC 8462852 between 2 May and 17 August 2017". BruceGary.net. Archived from the original on 20 August 2017. Retrieved 20 August 2017.
  54. ^ Gary, Bruce L. (8 September 2017). "Hereford Arizona Observatory photometry observations of KIC 8462852 between 2 May and 8 September 2017". BruceGary.net. Archived from the original on 8 September 2017. Retrieved 8 September 2017.
  55. ^ Gary, Bruce L. (10 September 2017). "Hereford Arizona Observatory photometry observations of KIC 8462852 between 2 May and 10 September 2017". BruceGary.net. Archived from the original on 10 September 2017. Retrieved 10 September 2017.
  56. PMID 29755143
    .
  57. ^ a b c d Gary, Bruce L. (16 December 2017). "KIC8462852 Hereford Arizona Observatory Photometry Observations #5". BruceGary.net. Archived from the original on 16 December 2017. Retrieved 16 December 2017.
  58. ^ Boyajian, Tabetha S. (6 November 2017). "Dip update 111/n". Where's the Flux?. Retrieved 7 November 2017.
  59. ^
    S2CID 118905159
    .
  60. ^
    S2CID 119041209
    .
  61. ^ Gary, Bruce L. (14 November 2017). "Hereford Arizona Observatory photometry observations of KIC 8462852". BruceGary.net. Retrieved 17 December 2017.
  62. ^ Boyajian, Tabetha S. (8 March 2018). "Dip update 130/n – The 2018 observing campaign begins!". Where's the Flux?. Retrieved 20 March 2018.
  63. ^ Boyajian, Tabetha S. (19 March 2018). "tldr: DIPPING!!!". Where's the Flux?. Retrieved 20 March 2018.
  64. ^ Adamson, Allan (27 March 2018). "Alien Megastructure Star: Dimming Of Tabby's Star Sets New Record". TechTimes.com. Retrieved 27 March 2018.
  65. ^ Boyajian, Tabetha S. (24 March 2018). "2018 March: dip update 6/n". Where's the Flux?. Retrieved 27 March 2018.
  66. ^ Boyajian, Tabetha S. (26 March 2018). "2018 March: dip update 7/n". Where's the Flux?. Retrieved 27 March 2018.
  67. ^ Boyajian, Tabetha S. (27 March 2018). "2018 March: dip update 8/n". Where's the Flux?. Retrieved 27 March 2018.
  68. ^ Boyajian, Tabetha S. (18 March 2019). "2019 data update (1/n)". Where's the Flux?. Retrieved 25 March 2019.
  69. ^ Boyajian, Tabetha S. (21 March 2019). "2019 data update (2/n)". Where's the Flux?. Retrieved 25 March 2019.
  70. ^ "Alert Notice 672: Monitoring needed of KIC 8462852 (Tabby's Star)". AAVSO. 19 July 2019. Retrieved 25 July 2019.
  71. ^ Boyajian, Tabetha [@tsboyajian] (9 October 2019). "I heard sector 15 is out..." (Tweet). Retrieved 9 October 2019 – via Twitter.
  72. ^ a b Gary, Bruce L. (11 January 2020). "KIC 8462852 Hereford Arizona Observatory Photometry Observations #9". Archived from the original on 5 April 2020. Retrieved 5 April 2020.
  73. ^
    Bibcode:2018JAVSO..46...14S
    .
  74. ^ a b c d Plait, Phil (14 October 2015). "Did Astronomers Find Evidence of an Alien Civilization? (Probably Not. But Still Cool.)". Slate. Retrieved 15 October 2015.
  75. ^ a b Andersen, Ross (13 October 2015). "The Most Mysterious Star in Our Galaxy". The Atlantic. Retrieved 13 October 2015.
  76. ^ Aron, Jacob (18 September 2015). "Citizen scientists catch cloud of comets orbiting distant star". New Scientist. Retrieved 15 October 2015.
  77. Skeptic
    . 21 (1): 16–18.
  78. S2CID 118514925
    .
  79. S2CID 38369896
    .
  80. ^ Prostak, Sergio (2 February 2021). "Milky Way's 'Most Mysterious Star' Has a Companion". Sci-News.com. Retrieved 3 February 2021.
  81. ^ "880 au / [distance from the sun to jupiter] - Wolfram|Alpha". www.wolframalpha.com. Retrieved 7 March 2023.
  82. ^ "880 au / [distance from the sun to neptune] - Wolfram|Alpha". www.wolframalpha.com. Retrieved 7 March 2023.
  83. ^ "880 au / [distance from the sun to voyager 1] - Wolfram|Alpha". www.wolframalpha.com. Retrieved 7 March 2023.
  84. ^ Powell, Corey S. & Wright, Jason T. (30 June 2017). "The Strangest (and Second-Strangest) Star in the Galaxy". Discover. Archived from the original on 5 November 2019. Retrieved 10 September 2017.
  85. ^ a b c Rzetelny, Xaq (16 October 2015). "Something—we're not sure what—is radically dimming a star's light". Ars Technica. Retrieved 17 October 2015.
  86. ^ Siegel, Ethan (16 October 2015). "No, Astronomers Probably Haven't Found 'Alien Megastructures'". Forbes. Retrieved 17 October 2015.
  87. ^ a b c d e Clavin, Whitney & Johnson, Michele (24 November 2015). "Strange Star Likely Swarmed by Comets". NASA. Retrieved 24 November 2015.
  88. ^
    S2CID 119304002
    .
  89. ^
    S2CID 119282226
    .
  90. ^
    S2CID 119502706
    .
  91. ^ Kohler, Susanna (7 July 2017). "Another Possibility for Boyajian's Star". AAS Nova. Retrieved 14 July 2017.
  92. ^ Guenzel, Jessica (16 September 2019). "Explain the Dimming of the Most Mysterious Star in the Universe". Columbia University. Retrieved 10 November 2019.
  93. ^
    S2CID 195316956
    .
  94. ^ a b c Landau, Elizabeth (4 October 2017). "Mysterious Dimming of Tabby's Star May Be Caused by Dust". NASA. Retrieved 4 October 2017.
  95. ^
    S2CID 118875846
    .
  96. ^ a b Tabor, Abby (4 October 2017). "The Scientific Quest to Explain Kepler's Most Enigmatic Find". NASA. Retrieved 5 October 2017.
  97. ^ Patel, Neel V. (8 September 2017). "We Finally Have Proof the Alien Megastructures Star is Not Aliens". Inverse. Retrieved 10 September 2017.
  98. ^ a b Drake, Nadia (3 January 2018). "Mystery of 'Alien Megastructure' Star Has Been Cracked". National Geographic. Archived from the original on 3 January 2018. Retrieved 4 January 2018.
  99. ^ Boyajian, Tabetha S. (4 October 2017). "Dip update 98/n". Where's the Flux?. Retrieved 4 October 2017.
  100. ^ a b Overbye, Dennis (10 January 2018). "Magnetic Secrets of Mysterious Radio Bursts in a Faraway Galaxy". The New York Times. Retrieved 11 January 2018.
  101. S2CID 125133896
    .
  102. ^ Redd, Nola Taylor (8 June 2018). "High School Students Help Unravel Mystery of Weirdly Dimming 'Tabby's Star'". Space.com. Retrieved 8 June 2018.
  103. S2CID 119466861
    .
  104. S2CID 119530135
    .
  105. ^ Reddy, Francis & Garner, Rob (21 December 2017). "New Study Finds 'Winking' Star May Be Devouring Wrecked Planets". NASA. Retrieved 22 December 2017.
  106. S2CID 118791549
    .
  107. ^ a b Fecht, Sarah (13 October 2015). "Have We Detected Megastructures Built By Aliens Around A Distant Star? Or Just A Cloud Of Comets? Scientists Want To Investigate Further". Popular Science. Retrieved 14 October 2015.
  108. S2CID 55506241
    .
  109. ^ Laker, Chris (16 October 2015). "'Alien megastructure' may explain light patterns from 'bizarre' star, say scientists". BT.com. Retrieved 17 October 2015.
  110. ^
    S2CID 119231384
    .
  111. ^ O'Callaghan, Jonathan (11 January 2017). "The Alien Megastructure Star May Have Eaten A Planet". IFL Science.
  112. S2CID 118987014
    .
  113. NBCNews
    . Retrieved 3 September 2017.
  114. ^
    S2CID 119399866
    .
  115. S2CID 119333732
    .
  116. ^
    doi:10.1103/Physics.9.150
    .
  117. ^
    PMID 28059527
    .
  118. doi:10.1016/j.actaastro.2015.07.011
    .
  119. Discovery.com. Archived from the original
    on 11 May 2016. Retrieved 17 October 2015.
  120. ^
    House Committee on Science, Space, and Technology. SpaceRef.com. Archived from the original
    on 23 October 2015. Retrieved 19 October 2015.
  121. ^ Kramer, Miriam (18 October 2015). "Scientists have not actually found an alien megastructure orbiting a distant star". Mashable. Retrieved 27 October 2016.
  122. Bibcode:2013AAS...22114212G
    .
  123. S2CID 119337919
    .
  124. ^ Carlson, Erika K. (18 September 2019). "Shredded exomoon may explain weird behavior of Tabby's Star". Astronomy. Retrieved 19 September 2019.
  125. S2CID 195700030
    .
  126. ^ Plait, Phil (18 September 2019). "Boyajian's Star: Could its bizarre behavior be due to an evaporating exomoon?". SyFy Wire. Retrieved 19 September 2019.
  127. ^ Wall, Mike (28 October 2015). "'Alien Megastructure' Mystery May Soon Be Solved". Space.com. Retrieved 28 October 2015.
  128. ^ Mack, Eric (17 October 2015). "The story behind 'alien megastructures' scientists may have found (but probably didn't)". CNET. Retrieved 19 October 2015.
  129. ^ Fecht, Sarah (16 June 2016). "'Alien Megastructure' Star Kickstarter Just Met Its Goal". Popular Science. Retrieved 16 June 2016.
  130. ^ Jarreau, Paige (17 January 2017). "Tabby's Star: The Most Mysterious Star in the Universe Needs You". The Pursuit. Physics and Astronomy.
  131. ^ "Subreddit FAQ". Subreddit.
  132. S2CID 54088872
    .
  133. S2CID 119476899
    .
  134. ^ Wall, Mike (19 October 2015). "Search For Intelligent Aliens Near Bizarre Dimming Star Has Begun". Space.com. Retrieved 20 October 2015.
  135. ^ Orwig, Jessica (23 October 2015). "Scientists are days from finding out if that mysterious star could actually harbor aliens". Business Insider.
  136. ^ "Looking for Deliberate Radio Signals from KIC 8462852" (Press release). The SETI Institute. 5 November 2015. Archived from the original on 7 November 2015. Retrieved 8 November 2015.
  137. ^
    S2CID 102491516
    .
  138. S2CID 119194869
    .
  139. S2CID 118384903
    .
  140. S2CID 119282495
    .
  141. ^ Koren, Marina (17 April 2017). "Searching the Skies for Alien Laser Beams". The Atlantic. Retrieved 3 June 2017.
  142. S2CID 119088358
    .
  143. ^ Korpela, Eric (7 September 2017). "Data from 'Tabby's Star' is flowing". University of California, Berkeley. Retrieved 12 September 2017.
  144. ^
    S2CID 8188464
    .
  145. ^ Nowakowski, Tomasz (30 August 2016). "Irregular dimming of a young stellar object investigated by astronomers". Phys.org. Retrieved 5 September 2016.
  146. ^ Starr, Michelle (28 September 2019). "Astronomers Have Found Another 21 Stars Dimming as Erratically as Tabby's Star". ScienceAlert.com. Retrieved 28 September 2019.
  147. S2CID 199676552
    .

External links

Wikimedia Commons has media related to KIC 8462852.

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