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Lyra

Coordinates: Sky map 19h 00m 00s, +40° 00′ 00″
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For other uses, see Lyra (disambiguation).
Lyra
Constellation
Lyra
List of stars in Lyra
AbbreviationLyr
GenitiveLyrae
Pronunciation/ˈlaɪrə/, genitive /ˈlaɪriː/
SymbolismLyre, harp
Right ascension18h 14m to 19h 28m
Declination25.66° to 47.71°
QuadrantNQ4
Area286 sq. deg. (52nd)
Main stars5
Bayer/Flamsteed
stars		25
Stars brighter than 3.00m1 (Vega)
Stars within 10.00 pc (32.62 ly)3[n 1]
Brightest starVega (α Lyr) (0.03m)
Messier objects2
Meteor showersLyrids
June Lyrids
Alpha Lyrids
Bordering
constellations		Draco
Hercules
Vulpecula
Cygnus
Visible at latitudes between +90° and −40°.
Best visible at 21:00 (9 p.m.) during the month of August.
[1]

Lyra (Latin for 'lyre', from Ancient Greek: λύρα; pronounced: /ˈlaɪrə/ LY-rə)[2] is a small constellation. It is one of the 48 listed by the 2nd century astronomer Ptolemy, and is one of the modern 88 constellations recognized by the International Astronomical Union. Lyra was often represented on star maps as a vulture or an eagle carrying a lyre, and hence is sometimes referred to as Vultur Cadens or Aquila Cadens ("Falling Vulture"[3] or "Falling Eagle"), respectively. Beginning at the north, Lyra is bordered by Draco, Hercules, Vulpecula, and Cygnus. Lyra is nearly overhead in temperate northern latitudes shortly after midnight at the start of summer. From the equator to about the 40th parallel south it is visible low in the northern sky during the same (thus winter) months.

Vega, Lyra's brightest star, is one of the brightest stars in the night sky, and forms a corner of the famed Summer Triangle asterism. Beta Lyrae is the prototype of a class of binary stars known as Beta Lyrae variables. These binary stars are so close to each other that they become egg-shaped and material flows from one to the other. Epsilon Lyrae, known informally as the Double Double, is a complex multiple star system. Lyra also hosts the Ring Nebula, the second-discovered and best-known planetary nebula.

History

[edit]
Lyra can be seen on the right of this c. 1825 star map from Urania's Mirror.

In Greek mythology, Lyra represents the lyre of Orpheus. Orpheus's music was said to be so great that even inanimate objects such as rocks could be charmed. Joining Jason and the Argonauts, his music was able to quell the voices of the dangerous Sirens, who sang tempting songs to the Argonauts.[4]

At one point, Orpheus married Eurydice, a nymph. While fleeing from an attack by Aristaeus, she stepped on a snake that bit her, killing her. To reclaim her, Orpheus entered the Underworld, where the music from his lyre charmed Hades, the god of the Underworld. Hades relented and let Orpheus bring Eurydice back, on the condition that he never once look back until outside. Unfortunately, near the very end, Orpheus faltered and looked back, causing Eurydice to be left in the Underworld forever. Orpheus spent the rest of his life strumming his lyre while wandering aimlessly through the land, rejecting all marriage offers from women.[4]

There are two main competing myths relating to the death of Orpheus. According to Eratosthenes, Orpheus failed to make a necessary sacrifice to Dionysus due to his regard for Apollo as the supreme deity instead. Dionysus then sent his followers to rip Orpheus apart. Ovid tells a rather different story, saying that women, in retribution for Orpheus's rejection of marriage offers, ganged up and threw stones and spears. At first, his music charmed them as well, but eventually their numbers and clamor overwhelmed his music and he was hit by the spears. Both myths then state that his lyre was placed in the sky by Zeus and Orpheus's bones were buried by the muses.[4] In a third myth, he was killed by the Thracian women because he looked on the rites of Father Liber (Dionysus).[5]

The Roman book De astronomia, attributed to Hyginus, also records another myth about Lyra, which said that it belonged to Theseus "for he was skilful in all the arts and seems to have learned the lyre as well". The book reports that the neighbouring constellation now known as Hercules was said to depict many different mythical figures, including Theseus, Orpheus, or the musician Thamyris.[5] The proximity of these two constellations and Corona Borealis (perhaps a symbol of Theseus' royalty) could indicate that the three constellations were invented as a group.[6]

Vega and its surrounding stars are also treated as a constellation in other cultures. The area corresponding to Lyra was seen by the Arabs as a vulture or an eagle diving with folded wings.[4] In Wales, Lyra is known as King Arthur's Harp (Talyn Arthur), and King David's harp. The Persian Hafiz called it the Lyre of Zurah. It has been called the Manger of the Infant Saviour, Praesepe Salvatoris.[7] In Australian Aboriginal astronomy, Lyra is known by the Boorong people in Victoria as the Malleefowl constellation.[8] Lyra was known as Urcuchillay by the Incas and was worshipped as an animal deity.[9][10]

Characteristics

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Lyra is bordered by Vulpecula to the south, Hercules to the west, Draco to the north, and Cygnus to the east. Covering 286.5 square degrees, it ranks 52nd of the 88 modern constellations in size. It appears prominently in the northern sky during the Northern Hemisphere's summer, and the whole constellation is visible for at least part of the year to observers north of latitude 42°S.[11][n 2] Its main asterism consists of six stars,[n 3] and 73 stars in total are brighter than magnitude 6.5.[11] The constellation's boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a 17-sided polygon. In the equatorial coordinate system, the right ascension coordinates of these borders lie between 18h 14m and 19h 28m , while the declination coordinates are between +25.66° and +47.71°.[12] The International Astronomical Union (IAU) adopted the three-letter abbreviation "Lyr" for the constellation in 1922.[13]

Features

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The constellation Lyra as it can be seen by the naked eye.

Stars

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See also: List of stars in Lyra
The constellation Lyra, enhanced for color and contrast. Brightest five stars are labeled.

German cartographer Johann Bayer used the Greek letters alpha through nu to label the most prominent stars in the constellation. English astronomer John Flamsteed observed and labelled two stars each as delta, epsilon, zeta and nu. He added pi and rho, not using xi and omicron as Bayer used these letters to denote Cygnus and Hercules on his map.[14]

The brightest star in the constellation is Vega (Alpha Lyrae), a main-sequence star of spectral type A0Va.[15] Only 7.7 parsecs distant,[16] Vega is a Delta Scuti variable, varying between magnitudes −0.02 and 0.07 over 0.2 days.[17] On average, it is the second-brightest star of the northern hemisphere (after Arcturus) and the fifth-brightest star in all, surpassed only by Arcturus, Alpha Centauri, Canopus, and Sirius. Vega was the pole star in the year 12,000 BCE, and will again become the pole star around 14,000 CE.[18][19]

Vega is one of the most magnificent of all stars, and has been called "arguably the next most important star in the sky after the Sun".[20] Vega was the first star other than the Sun to be photographed,[21] as well as the first to have a clear spectrum recorded, showing absorption lines for the first time.[22] The star was the first single main-sequence star other than the Sun to be known to emit X-rays,[23] and is surrounded by a circumstellar debris disk, similar to the Kuiper Belt.[24] Vega forms one corner of the famous Summer Triangle asterism; along with Altair and Deneb, these three stars form a prominent triangle during the northern hemisphere summer.[25]

Vega also forms one vertex of a much smaller triangle, along with Epsilon and Zeta Lyrae. Zeta forms a wide binary star visible in binoculars, consisting of an Am star and an F-type subgiant. The Am star has an additional close companion, bringing the total number of stars in the system to three.[26] Epsilon is a more famous wide binary that can even be separated by the naked eye under excellent conditions.[27] Both components are themselves close binaries which can be seen with telescopes to consist of A- and F-type stars, and a faint star was recently found to orbit component C as well, for a total of five stars.[26]

In contrast to Zeta and Epsilon Lyrae, Delta Lyrae is an optical double, with the two stars simply lying along the same line of sight east of Zeta. The brighter and closer of the two, Delta2 Lyrae, is a 4th-magnitude red bright giant that varies semiregularly by around 0.2 magnitudes[28] with a dominant period of 79 days,[29] while the fainter Delta1 Lyrae is a spectroscopic binary consisting of a B-type primary and an unknown secondary.[26] Both systems, however, have very similar radial velocities, and are the two brightest members of a sparse open cluster known as the Delta Lyrae cluster.[30]

South of Delta is Sulafat (Gamma Lyrae), a blue giant and the second-brightest star in the constellation. Around 190 parsecs distant,[16] it has been referred to as a "superficially normal" star.[31]

The final star forming the lyre's figure is Sheliak (Beta Lyrae), also a binary composed of a blue bright giant and an early B-type star.[32][33][34] In this case, the stars are so close together that the larger giant is overflowing its Roche lobe and transferring material to the secondary, forming a semidetached system. The secondary, originally the less massive of the two, has accreted so much mass that it is now substantially more massive, albeit smaller, than the primary, and is surrounded by a thick accretion disk.[35] The plane of the orbit is aligned with Earth and the system thus shows eclipses, dropping nearly a full magnitude from its 3rd-magnitude baseline every 13 days,[36] although its period is increasing by around 19 seconds per year.[37] It is the prototype of the Beta Lyrae variables, eclipsing semidetached binaries of early spectral types in which there are no exact onsets of eclipses, but rather continuous changes in brightness.[38]

A long-exposure image of Lyra

Another easy-to-spot variable is the bright R Lyrae, north of the main asterism. Also known as 13 Lyrae, it is a 4th-magnitude red giant semiregular variable that varies by several tenths of a magnitude.[39] Its periodicity is complex, with several different periods of varying lengths, most notably one of 46 days and one of 64 days.[40] Even further north is FL Lyrae, a much fainter 9th-magnitude Algol variable that drops by half a magnitude every 2.18 days during the primary eclipse. Both components are main-sequence stars, the primary being late F-type and the secondary late G-type. The system was one of the first main-sequence eclipsing binaries containing G-type star to have its properties known as well as the better-studied early-type eclipsing binaries.[41]

At the very northernmost edge of the constellation is the even fainter V361 Lyrae, an eclipsing binary that does not easily fall into one of the traditional classes, with features of Beta Lyrae, W Ursae Majoris, and cataclysmic variables.[42][43] It may be a representative of a very brief phase in which the system is transitioning into a contact binary.[44] It can be found less than a degree away from the naked-eye star 16 Lyrae, a 5th-magnitude A-type subgiant[45] located around 37 parsecs distant.[16]

The brightest star not included in the asterism and the westernmost cataloged by Bayer or Flamsteed is Kappa Lyrae, a typical red giant[46] around 73 parsecs distant.[16] Similar bright orange or red giants include the 4th-magnitude Theta Lyrae,[47] Lambda Lyrae,[48] and HD 173780.[46] Lambda is located just south of Gamma, Theta is positioned in the east, and HD 173780, the brightest star in the constellation with no Bayer or Flamsteed designation, is more southernly. Just north of Theta and of almost exactly the same magnitude is Eta Lyrae, a blue subgiant with a near-solar metal abundance.[49] Also nearby is the faint HP Lyrae, a post-asymptotic giant branch (AGB) star that shows variability. The reason for its variability is still a mystery: first cataloged as an eclipsing binary, it was theorized to be an RV Tauri variable in 2002, but if so, it would be by far the hottest such variable discovered.[50]

In the extreme east is RR Lyrae, the prototype of the large class of variables known as RR Lyrae variables, which are pulsating variables similar to Cepheids, but are evolved population II stars of spectral types A and F. Such stars are usually not found in a galaxy's thin disk, but rather in the galactic halo. Such stars serve as standard candles, and thus are a reliable way to calculate distances to the globular clusters in which they reside.[38] RR Lyrae itself varies between magnitudes 7 and 8 while exhibiting the Blazhko effect.[51] The easternmost star designated by Flamsteed, 19 Lyrae, is also a small-amplitude variable, an Alpha2 Canum Venaticorum variable with a period of just over one day.[52]

Another evolved star is the naked-eye variable XY Lyrae, a red bright giant[46] just north of Vega that varies between 6th and 7th magnitudes over a period of 120 days.[53] Also just visible to the naked eye is the peculiar classical Cepheid V473 Lyrae. It is unique in that it is the only known Cepheid in the Milky Way to undergo periodic phase and amplitude changes, analogous to the Blazhko effect in RR Lyrae stars.[54] At 1.5 days, its period was the shortest known for a classical Cepheid at the time of its discovery.[55] W and S Lyrae are two of the many Mira variables in Lyra. W varies between 7th and 12th magnitudes over approximately 200 days,[56] while S, slightly fainter, is a silicate carbon star, likely of the J-type.[57] Another evolved star is EP Lyrae, a faint RV Tauri variable and an "extreme example" of a post-AGB star. It and a likely companion are surrounded by a circumstellar disk of material.[58]

Rather close to Earth at a distance of only 16 parsecs (52 ly) is Gliese 758. The sunlike primary star has a brown dwarf companion, the coldest to have been imaged around a sunlike star in thermal light when it was discovered in 2009.[59] Only slightly farther away is V478 Lyrae, an eclipsing[60] RS Canum Venaticorum variable whose primary star shows active starspot activity.[61]

One of the most peculiar systems in Lyra is MV Lyrae, a nova-like star consisting of a red dwarf and a white dwarf.[62] Originally classified as a VY Sculptoris star due to spending most time at maximum brightness, since around 1979 the system has been dominantly at minimum brightness, with periodic outbursts.[63] Its nature is still not fully understood.[64] Another outbursting star is AY Lyrae, an SU Ursae Majoris-type dwarf nova that has undergone several superoutbursts.[65] Of the same type is V344 Lyrae, notable for an extremely short period between superoutbursts coupled with one of the highest amplitudes for such a period.[66] The true nova HR Lyrae flared in 1919 to a maximum magnitude of 6.5, over 9.5 magnitudes higher than in quiescence. Some of its characteristics are similar to those of recurring novae.[67]

Deep-sky objects

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Messier 56 is composed of a large number of stars, tightly bound to each other by gravity.[68] In Lyra are the objects M56, M57, and Kuiper 90. M56 is a rather loose globular cluster at a distance of approximately 32,900 light-years, with a diameter of about 85 light-years. Its apparent brightness is 8.3m.

M57, also known as the "Ring Nebula" and NGC 6720,[69] at a distance of 2,550 light-years from Earth is one of the best known planetary nebulae and the second to be discovered; its integrated magnitude is 8.8.[70] It was discovered in 1779 by Antoine Darquier, 15 years after Charles Messier discovered the Dumbbell Nebula.[71] Astronomers have determined that it is between 6,000 and 8,000 years old;[70] it is approximately one light-year in diameter.[72] The outer part of the nebula appears red in photographs because of emission from ionized hydrogen. The middle region is colored green; doubly ionized oxygen emits greenish-blue light. The hottest region, closest to the central star, appears blue because of emission from helium. The central star itself is a white dwarf with a temperature of 120,000 kelvins. In telescopes, the nebula appears as a visible ring with a green tinge; it is slightly elliptical because its three-dimensional shape is a torus or cylinder seen from a slight angle.[70] It can be found halfway between Gamma Lyrae and Beta Lyrae.[72]

Another planetary nebula in Lyra is Abell 46. The central star, V477 Lyrae, is an eclipsing post-common-envelope binary, consisting of a white dwarf primary and an oversized secondary component due to recent accretion. The nebula itself is of relatively low surface brightness compared to the central star,[73] and is undersized for the primary's mass for reasons not yet fully understood.[74]

NGC 6791 is a cluster of stars in Lyra. It contains three age groups of stars: 4 billion year-old white dwarfs, 6 billion year-old white dwarfs and 8 billion year-old normal stars.[75]

NGC 6745 is an irregular spiral galaxy in Lyra that is at a distance of 208 million light-years. Several million years ago, it collided with a smaller galaxy, which created a region filled with young, hot, blue stars. Astronomers do not know if the collision was simply a glancing blow or a prelude to a full-on merger, which would end with the two galaxies incorporated into one larger, probably elliptical galaxy.[70]

A remarkable long-duration gamma-ray burst was GRB 050525A, which flared in 2005. The afterglow re-brightened at 33 minutes after the original burst, only the third found to exhibit such an effect in the timeframe,[76] and unable to be completely explained by known phenomena.[77] The light curve observed over the next 100 days was consistent with that of a supernova or even a hypernova, dubbed SN 2005nc.[78] The host galaxy proved elusive to find at first,[79] although it was subsequently identified.[80]

Exoplanets

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In orbit around the orange subgiant star HD 177830 is one of the earliest exoplanets to be detected. A jovian-mass planet, it orbits in an eccentric orbit with a period of 390 days.[81] A second planet closer to the star was discovered in 2011.[82] Visible to the naked eye are HD 173416, a yellow giant hosting a planet over twice the mass of Jupiter discovered in 2009;[83] and HD 176051, a low-mass binary star containing another high-mass planet.[84] Just short of naked-eye visibility is HD 178911, a triple system consisting of a close binary and a visually separable sunlike star. The sunlike star has a planet with over 6 Jupiter masses discovered in 2001, the second found in a triple system after that of 16 Cygni.[85]

One of the most-studied exoplanets in the night sky is TrES-1b, in orbit around the star GSC 02652-01324. Detected from a transit of its parent star, the planet has around 3/4 the mass of Jupiter, yet orbits its parent star in only three days.[86] The transits have been reported to have anomalies multiple times. Originally thought to be possibly due to the presence of an Earth-like planet, it is now accepted that the irregularities are due to a large starspot.[87] Also discovered by the transit method is WASP-3b, with 1.75 times the mass of Jupiter. At the time of its discovery, it was one of the hottest known exoplanets, in orbit around the F-type main-sequence star WASP-3.[88] Similar to TrES-1b, irregularities in the transits had left open the possibility of a second planet, although this now appears unlikely as well.[89]

Lyra is one of three constellations (along with neighboring Cygnus and Draco) to be in the Kepler Mission's field of view, and as such it contains many more known exoplanets than most constellations. One of the first discovered by the mission is Kepler-7b, an extremely low-density exoplanet with less than half the mass of Jupiter, yet nearly 1.5 times the radius.[90] Almost as sparse is Kepler-8b, only slightly more massive and of a similar radius.[91] The Kepler-20 system contains five known planets; three of them are only slightly smaller than Neptune,[92] while the other two are some of the first Earth-sized exoplanets to be discovered.[93] Kepler-37 is another star with an exoplanet discovered by Kepler; the planet is the smallest known extrasolar planet known as of February 2013.

In April 2013, it was announced that of the five planets orbiting Kepler-62, at least two—Kepler-62e and Kepler-62f—are within the boundaries of the habitable zone of that star, where scientists think liquid water could exist, and are both candidates for being a solid, rocky, earth-like planet.[94][95] The exoplanets are 1.6 and 1.4 times the diameter of Earth respectively,[94] with their star Kepler-62 at a distance of 1,200 light-years.[96]

See also

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Notes

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  1. ^ The nearby stars are Vega, the red dwarf double star GJ 747, and the brown dwarf 2MASS 1835+3259.
  2. ^ While parts of the constellation technically rise above the horizon to observers between 42°S and 64°S, stars within a few degrees of the horizon are to all intents and purposes unobservable.
  3. ^ Assuming the visual binary Epsilon is counted as single stars, and only one of Delta1 and Delta2 Lyrae is counted as part of the pattern.

References

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  1. ^ Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide, Collins, London. ISBN 978-0-00-725120-9. Princeton University Press, Princeton. ISBN 978-0-691-13556-4.
  2. ^ Lesley Brown: The New Shorter Oxford English Dictionary. Vol. 1: A−M. Clarendon Press, Oxford 1993, p. 1651
  3. ^ Bistue, Belen (May 23, 2016). Collaborative Translation and Multi-Version Texts in Early Modern Europe. Routledge. pp. 72–73. ISBN 978-1317164357.
  4. ^ a b c d Ridpath, Ian. "Star Tales - Lyra". Star Tales. self-published. Archived from the original on 3 September 2021. Retrieved 3 September 2021.
  5. ^ a b Grant, Mary. "Hyginus, Astronomica: 2.6 'The Kneeler'". Theoi Project. Archived from the original on 2017-12-24. Retrieved 2017-12-24.
  6. ^ "Hercules, originally known as Engonasin, the Kneeler". Constellation Myths. Translated by Hard, Robin. Oxford University Press. 2015. ISBN 9780191026539.
  7. ^ Allen, Richard Hinckley (1963) [1899]. Star Names: Their Lore and Meaning. Dover Publications, Inc. ISBN 0-486-21079-0.
  8. ^ "World_Archaeological_Congress.pdf" (PDF). The Astronomy of the Boorong. Archived from the original (PDF) on March 26, 2009. Retrieved 2007-10-17.
  9. ^ Allen, Richard Hinckley (2003) [1936]. Star Names and Their Meanings. Kessenger Publishing. ISBN 978-0-7661-4028-8.[permanent dead link]
  10. ^ D'Altroy, Terence N. (2002). "The Inca Pantheon". The Incas. The Peoples of America. Oxford: Blackwell Publishing. p. 149. ISBN 978-0-631-17677-0.
  11. ^ a b Ridpath, Ian. "Constellations: Lacerta–Vulpecula". Star Tales. self-published. Archived from the original on 16 December 2017. Retrieved 25 July 2015.
  12. ^ "Lyra, Constellation Boundary". The Constellations. International Astronomical Union. Archived from the original on 4 June 2013. Retrieved 25 July 2015.
  13. ^ Russell, H. N. (1922). "The New International Symbols for the Constellations". Popular Astronomy. 30: 469–71. Bibcode:1922PA.....30..469R.
  14. ^ Wagman, Morton (2003). Lost Stars: Lost, Missing and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas Louis de Lacaille, John Flamsteed, and Sundry Others. Blacksburg, Virginia: The McDonald & Woodward Publishing Company. pp. 204–06. ISBN 978-0-939923-78-6.
  15. ^ Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Robinson, P. E. (2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I". The Astronomical Journal. 132 (1): 161–70. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID 119476992.
  16. ^ a b c d van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
  17. ^ Breger, M. (1979). "Delta Scuti and related stars". Publications of the Astronomical Society of the Pacific. 91: 5–26. arXiv:astro-ph/0003373v1. Bibcode:1979PASP...91....5B. doi:10.1086/130433. S2CID 16994385.
  18. ^ Roy, Archie E.; et al. (2003). Astronomy: Principles and Practice. CRC Press. ISBN 978-0-7503-0917-2.
  19. ^ Allen, Richard Hinckley (1963). Star Names: Their Lore and Meaning. Courier Dover Publications. ISBN 978-0-486-21079-7.
  20. ^ Gulliver, A. F.; Hill, G.; Adelman, S. J. (1994). "Vega: A rapidly rotating pole-on star". The Astrophysical Journal. 429 (2): L81–L84. Bibcode:1994ApJ...429L..81G. doi:10.1086/187418.
  21. ^ Holden, E. S.; Campbell, W. W. (1890). "Photographs of Venus, Mercury and Alpha Lyræ in Daylight". Publications of the Astronomical Society of the Pacific. 2 (10): 249–250. Bibcode:1890PASP....2..249H. doi:10.1086/120156. S2CID 120286863.
  22. ^ Barker, G. F. (1887). "On the Henry Draper Memorial Photographs of Stellar Spectra". Proceedings of the American Philosophical Society. 24 (125): 166–172. JSTOR 983130.
  23. ^ Topka, K.; et al. (1979), "Detection of soft X-rays from Alpha Lyrae and Eta Bootis with an imaging X-ray telescope", Astrophysical Journal, 229: 661, Bibcode:1979ApJ...229..661T, doi:10.1086/157000
  24. ^ Su, K. Y. L.; et al. (2005), "The Vega Debris Disk: A Surprise from Spitzer", The Astrophysical Journal, 628 (1): 487–500, arXiv:astro-ph/0504086, Bibcode:2005ApJ...628..487S, doi:10.1086/430819, S2CID 18898968
  25. ^ Ian Ridpath (2012). The Monthly Sky Guide. Cambridge University Press. p. 14. ISBN 978-1-139-62066-6.
  26. ^ a b c Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
  27. ^ Burnham, Robert (1966). Burnham's Celestial Handbook. Dover Publications Inc. pp. 1151–1153. ISBN 0-486-24064-9.
  28. ^ Bakos, G. A.; Tremko, J. (1991). "A photometric and spectroscopic study of δ2 Lyrae". Contrib. Astron. Obs. Skalnaté Pleso. 21: 99–106. Bibcode:1991CoSka..21...99B.
  29. ^ Lloyd, C.; West, K. W. (1996). "Observations of Low-amplitude Late-Type Variables". Information Bulletin on Variable Stars. 4335 (4335): 1. Bibcode:1996IBVS.4335....1L.
  30. ^ Eggen, O. J. (1968). "Photometric evidence for the existence of a delta Lyrae cluster". Astrophysical Journal. 152: 77. Bibcode:1968ApJ...152...77E. doi:10.1086/149525.
  31. ^ Adelman, S. J.; Caliskan, H.; Kocer, D.; Kablan, H.; Yüce, K.; Engin, S. (2001). "Elemental abundance analyses with DAO spectrograms". Astronomy and Astrophysics. 371 (3): 1078–1083. Bibcode:2001A&A...371.1078A. doi:10.1051/0004-6361:20010408.
  32. ^ Bastian, U. (2019). "Gaia 8: Discovery of a star cluster containing β Lyrae". Astronomy & Astrophysics. 630: L8. arXiv:1909.04612. Bibcode:2019A&A...630L...8B. doi:10.1051/0004-6361/201936595.
  33. ^ Mourard, D.; Brož, M.; Nemravová, J. A.; Harmanec, P.; Budaj, J.; Baron, F.; Monnier, J. D.; Schaefer, G. H.; Schmitt, H.; Tallon-Bosc, I.; Armstrong, J. T.; Baines, E. K.; Bonneau, D.; Božić, H.; Clausse, J. M.; Farrington, C.; Gies, D.; Juryšek, J.; Korčáková, D.; McAlister, H.; Meilland, A.; Nardetto, N.; Svoboda, P.; Šlechta, M.; Wolf, M.; Zasche, P. (2018). "Physical properties of β Lyrae a and its opaque accretion disk". Astronomy and Astrophysics. 618: A112. arXiv:1807.04789. Bibcode:2018A&A...618A.112M. doi:10.1051/0004-6361/201832952. S2CID 73647379.
  34. ^ Zhao, M.; et al. (September 2008), "First Resolved Images of the Eclipsing and Interacting Binary β Lyrae", The Astrophysical Journal, 684 (2): L95–L98, arXiv:0808.0932, Bibcode:2008ApJ...684L..95Z, doi:10.1086/592146, S2CID 17510817.
  35. ^ Harmanec, P. (2002). "The ever challenging emission-line binary β Lyrae". Astronomische Nachrichten. 323 (2): 87–98. Bibcode:2002AN....323...87H. doi:10.1002/1521-3994(200207)323:2<87::AID-ASNA87>3.0.CO;2-P.
  36. ^ European Space Agency (1997). The HIPPARCOS and TYCHO catalogues. Astrometric and photometric star catalogues derived from the ESA HIPPARCOS Space Astrometry Mission. Vol. 1200. Netherlands: Noordwijk. Bibcode:1997ESASP1200.....E. ISBN 9290923997. {{cite book}}: |journal= ignored (help)
  37. ^ Zhao, M.; et al. (2008), "First Resolved Images of the Eclipsing and Interacting Binary β Lyrae", The Astrophysical Journal, 684 (2): L95–L98, arXiv:0808.0932, Bibcode:2008ApJ...684L..95Z, doi:10.1086/592146, S2CID 17510817
  38. ^ a b Otero, S. A.; Watson, C.; Wils, P. "Variable Star Type Designations in the VSX". AAVSO Website. American Association of Variable Star Observers. Archived from the original on 11 April 2020. Retrieved 29 July 2015.
  39. ^ Koen, Chris; Eyer, Laurent (2002). "New periodic variables from the Hipparcos epoch photometry". Monthly Notices of the Royal Astronomical Society. 331 (1): 45–59. arXiv:astro-ph/0112194. Bibcode:2002MNRAS.331...45K. doi:10.1046/j.1365-8711.2002.05150.x. S2CID 10505995.
  40. ^ Percy, John R.; Wilson, Joseph B.; Henry, Gregory W. (2001). "Long-TermVRIPhotometry of Small-Amplitude Red Variables. I. Light Curves and Periods". Publications of the Astronomical Society of the Pacific. 113 (786): 983–996. Bibcode:2001PASP..113..983P. doi:10.1086/322153.
  41. ^ Popper, D. M.; Lacy, C. H.; Frueh, M. L.; Turner, A. E. (1986). "Properties of main-sequence eclipsing binaries - Into the G stars with HS Aurigae, FL Lyrae, and EW Orionis". The Astronomical Journal. 91: 383. Bibcode:1986AJ.....91..383P. doi:10.1086/114018.
  42. ^ Andronov, I. L.; Richter, G. A. (1987). "V 361 Lyrae: An exotic binary system with a "Hot Spot" between the components?". Astronomische Nachrichten. 308 (4): 235–238. Bibcode:1987AN....308..235A. doi:10.1002/asna.2113080403.
  43. ^ Shugarov, S. Y.; Goranskij, V. P.; Galkina, M. P.; Lipunova, N. A. (June 1990). "The Unique Manifestation of the Matter Outflow in the Eclipsing Binary System V361 Lyr". Information Bulletin on Variable Stars. 3472 (3472): 1. Bibcode:1990IBVS.3472....1S.
  44. ^ Hilditch, R. W.; Collier Cameron, A.; Hill, G.; Bell, S. A.; Harries, T. J. (1997). "Spectroscopy and eclipse-mapping of the mass-exchanging binary star V361 LYR". Monthly Notices of the Royal Astronomical Society. 291 (4): 749–792. Bibcode:1997MNRAS.291..749H. doi:10.1093/mnras/291.4.749.
  45. ^ Abt, H. A.; Morrell, N. I. (1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". Astrophysical Journal Supplement. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182.
  46. ^ a b c Keenan, P.; McNeil, R. (October 1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series. 71: 245–266. Bibcode:1989ApJS...71..245K. doi:10.1086/191373.
  47. ^ Montes, D.; López-Santiago, J.; Gálvez, M.C.; Fernández-Figueroa, M.J.; De Castro, E.; Cornide, M. (2001). "Late-type members of young stellar kinematic groups - I. Single stars". Monthly Notices of the Royal Astronomical Society. 328 (1): 45–63. arXiv:astro-ph/0106537. Bibcode:2001MNRAS.328...45M. doi:10.1046/j.1365-8711.2001.04781.x. S2CID 55727428.
  48. ^ Garcia, B. (1989). "A list of MK standard stars". Bulletin d'Information du Centre de Données Stellaires. 36: 27. Bibcode:1989BICDS..36...27G.
  49. ^ Adelman, S. J. (1998). "Elemental abundance analyses with DAO spectrograms - XIX. The superficially normal B stars ζ Draconis, η Lyrae, 8 Cygni and 22 Cygni". Monthly Notices of the Royal Astronomical Society. 296 (4): 856–862. Bibcode:1998MNRAS.296..856A. doi:10.1046/j.1365-8711.1998.01426.x.
  50. ^ Graczyk, D.; Mikolajewski, M.; Leedjarv, L.; Frackowiak, S. M.; Osiwala, J. P.; Puss, A.; Tomov, T. (2002). "HP Lyr - Possibly the Hottest RV Tau Type Object". Acta Astronomica. 52: 293–304. arXiv:astro-ph/0210448. Bibcode:2002AcA....52..293G.
  51. ^ Nemec, James M.; Cohen, Judith G.; Ripepi, Vincenzo; Derekas, Aliz; Moskalik, Pawel; Sesar, Branimir; Chadid, Merieme; Bruntt, Hans (2013). "Metal Abundances, Radial Velocities, and Other Physical Characteristics for the Rr Lyrae Stars in Thekeplerfield". The Astrophysical Journal. 773 (2): 181. arXiv:1307.5820. Bibcode:2013ApJ...773..181N. doi:10.1088/0004-637X/773/2/181. S2CID 59324293.
  52. ^ Burke, E. W. Jr.; Barr, T. H. (1981). "Photometric UBV period study of eight AP stars". Publications of the Astronomical Society of the Pacific. 93: 344. Bibcode:1981PASP...93..344B. doi:10.1086/130836.
  53. ^ Percy, J. R.; Dunlop, H.; Kassim, L.; Thompson, R. R. (2001). "Periods of 25 Pulsating Red Giants". Information Bulletin on Variable Stars. 5041 (5041): 1. Bibcode:2001IBVS.5041....1P.
  54. ^ Molnar, L.; Szabados, L. (2014). "V473 Lyrae, a unique second-overtone Cepheid with two modulation cycles". Monthly Notices of the Royal Astronomical Society. 442 (4): 3222–3234. arXiv:1406.0494. Bibcode:2014MNRAS.442.3222M. doi:10.1093/mnras/stu1091. S2CID 118591859.
  55. ^ Breger, M. (1981). "The unusual Cepheid HR 7308 with a variable amplitude". The Astrophysical Journal. 249: 666. Bibcode:1981ApJ...249..666B. doi:10.1086/159327.
  56. ^ Isles, J. E.; Saw, D. R. B. (1989). "Mira Stars - IV: R Cam, R Cas, W Cas, S Cep, T Cep, U Cyg, and S Del". Journal of the British Astronomical Association. 99 (6): 275–281. Bibcode:1989JBAA...99..275I.
  57. ^ Chen, P.-S.; Wang, X.-H. (2001). "IRAS 19111+2555(=S Lyr): A Possible Silicate Carbon Star". Chinese Journal of Astronomy & Astrophysics. 1 (4): 344–348. Bibcode:2001ChJAA...1..344C. doi:10.1088/1009-9271/1/4/344.
  58. ^ Gielen, C.; Van Winckel, H.; Matsuura, M.; Min, M.; Deroo, P.; Waters, L. B. F. M.; Dominik, C. (2009). "Analysis of the infrared spectra of the peculiar post-AGB stars EP Lyrae and HD 52961". Astronomy and Astrophysics. 503 (3): 843–854. arXiv:0906.4718. Bibcode:2009A&A...503..843G. doi:10.1051/0004-6361/200912060. S2CID 1673092.
  59. ^ Thalmann, C.; Carson, J.; Janson, M.; Goto, M.; McElwain, M.; Egner, S.; Feldt, M.; Hashimoto, J.; Hayano, Y.; Henning, T.; Hodapp, K. W.; Kandori, R.; Klahr, H.; Kudo, T.; Kusakabe, N.; Mordasini, C.; Morino, J.-I.; Suto, H.; Suzuki, R.; Tamura, M. (2009). "Discovery of the Coldest Imaged Companion of a Sun-Like Star". The Astrophysical Journal. 707 (2): L123–L127. arXiv:0911.1127. Bibcode:2009ApJ...707L.123T. doi:10.1088/0004-637X/707/2/L123. S2CID 116823073.
  60. ^ Hall, D. S.; Sowell, J. R.; Henry, G. W. (1989). "Discovery of Eclipses in the Chromospherically Active Binary V478 Lyrae=HD 178450". Bulletin of the American Astronomical Society. 21: 709. Bibcode:1989BAAS...21..709H.
  61. ^ Horne, J. D. (2006). "V478 Lyrae Revisited: a Current Look at Eclipses and Star Spots". The Journal of the American Association of Variable Star Observers. 34 (2): 177–187. Bibcode:2006JAVSO..34..177H.
  62. ^ Skillman, David R.; Patterson, Joseph; Thorstensen, John R. (1995). "Superhumps in Cataclysmic Binaries. IV. MV Lyrae". Publications of the Astronomical Society of the Pacific. 107: 545. Bibcode:1995PASP..107..545S. doi:10.1086/133590.
  63. ^ Pavlenko, E. P.; Shugarov, S. Y. (1999). "Photometric study of the nova-like variable MV Lyrae during an enormous outburst in 1997". Astronomy and Astrophysics. 343: 909–915. Bibcode:1999A&A...343..909P.
  64. ^ Linnell, Albert P.; Szkody, Paula; Gansicke, Boris; Long, Knox S.; Sion, Edward M.; Hoard, D. W.; Hubeny, Ivan (2005). "MV Lyrae in Low, Intermediate, and High States". The Astrophysical Journal. 624 (2): 923–933. arXiv:astro-ph/0612696. Bibcode:2005ApJ...624..923L. doi:10.1086/429143. S2CID 9017292.
  65. ^ Szymanski, M.; Udalski, A. (1987). "AY Lyrae Superoutburst Photometry". Information Bulletin on Variable Stars. 3105: 1. Bibcode:1987IBVS.3105....1S.
  66. ^ Kato, T.; Poyner, G.; Kinnunen, T. (2002). "V344 Lyr: an unusual large-amplitude SU UMa-type dwarf nova with a short supercycle". Monthly Notices of the Royal Astronomical Society. 330 (1): 53–57. arXiv:astro-ph/0110317. Bibcode:2002MNRAS.330...53K. doi:10.1046/j.1365-8711.2002.05015.x. S2CID 16338791.
  67. ^ Shears, J.; Poyner, G. (2007). "HR Lyrae (Nova Lyr 1919): from outburst to active quiescence". Journal of the British Astronomical Association. 117 (3): 136–141. arXiv:astro-ph/0701719. Bibcode:2007JBAA..117..136S.
  68. ^ "A Collection of Ancient Stars". ESA/Hubble Picture of the Week. Retrieved 20 August 2012.
  69. ^ Levy, David H. (2005). Deep Sky Objects. Prometheus Books. p. 123. ISBN 1-59102-361-0.
  70. ^ a b c d Wilkins, Jamie; Dunn, Robert (2006). 300 Astronomical Objects: A Visual Reference to the Universe. Buffalo, New York: Firefly Books. ISBN 978-1-55407-175-3.
  71. ^ Levy 2005, p. 125.
  72. ^ a b Levy 2005, p. 124.
  73. ^ Pollacco, D. L.; Bell, S. A. (1994). "A preliminary analysis of the planetary nebula central star V477 Lyrae". Monthly Notices of the Royal Astronomical Society. 267 (2): 452–464. Bibcode:1994MNRAS.267..452P. doi:10.1093/mnras/267.2.452.
  74. ^ Corradi, Romano L. M.; García-Rojas, Jorge; Jones, David; Rodríguez-Gil, Pablo (2015). "Binarity and the Abundance Discrepancy Problem in Planetary Nebulae". The Astrophysical Journal. 803 (2): 99. arXiv:1502.05182. Bibcode:2015ApJ...803...99C. doi:10.1088/0004-637X/803/2/99. S2CID 118565181.
  75. ^ "NASA - What's My Age? Mystery Star Cluster Has 3 Different Birthdays". www.nasa.gov. Archived from the original on 2017-06-09. Retrieved 2017-02-13.
  76. ^ Klotz, A.; Boër, M.; Atteia, J. L.; Stratta, G.; Behrend, R.; Malacrino, F.; Damerdji, Y. (2005). "Early re-brightening of the afterglow of GRB 050525a". Astronomy and Astrophysics. 439 (3): L35–L38. arXiv:astro-ph/0506259. Bibcode:2005A&A...439L..35K. doi:10.1051/0004-6361:200500153. S2CID 18532205.
  77. ^ Resmi, L.; Misra, K.; Jóhannesson, G.; Castro-Tirado, A. J.; Gorosabel, J.; Jelínek, M.; Bhattacharya, D.; Kubánek, P.; Anupama, G. C.; Sota, A.; Sahu, D. K.; de Ugarte Postigo, A.; Pandey, S. B.; Sánchez-Ramírez, R.; Bremer, M.; Sagar, R. (2012). "Comprehensive multiwavelength modelling of the afterglow of GRB 050525A". Monthly Notices of the Royal Astronomical Society. 427 (1): 288–297. arXiv:1207.3003. Bibcode:2012MNRAS.427..288R. doi:10.1111/j.1365-2966.2012.21713.x. S2CID 117826705.
  78. ^ Della Valle, M.; Malesani, D.; Bloom, J. S.; Benetti, S.; Chincarini, G.; D'Avanzo, P.; Foley, R. J.; Covino, S.; Melandri, A.; Piranomonte, S.; Tagliaferri, G.; Stella, L.; Gilmozzi, R.; Antonelli, L. A.; Campana, S.; Chen, H.-W.; Filliatre, P.; Fiore, F.; Fugazza, D.; Gehrels, N.; Hurley, K.; Mirabel, I. F.; Pellizza, L. J.; Piro, L.; Prochaska, J. X. (2006). "Hypernova Signatures in the Late Rebrightening of GRB 050525A". The Astrophysical Journal. 642 (2): L103–L106. arXiv:astro-ph/0604109. Bibcode:2006ApJ...642L.103D. doi:10.1086/504636. S2CID 15900738.
  79. ^ Zinn, P.-C.; Grunden, P.; Bomans, D. J. (2011). "Supernovae without host galaxies?". Astronomy & Astrophysics. 536: A103. arXiv:1109.4717. Bibcode:2011A&A...536A.103Z. doi:10.1051/0004-6361/201117631. S2CID 119212572.
  80. ^ Heng, Kevin; Lazzati, Davide; Perna, Rosalba; Garnavich, Peter; Noriega-Crespo, Alberto; Bersier, David; Matheson, Thomas; Pahre, Michael (2008). "A Direct Measurement of the Dust Extinction Curve in an Intermediate-Redshift Galaxy". The Astrophysical Journal. 681 (2): 1116–1122. arXiv:0803.2879. Bibcode:2008ApJ...681.1116H. doi:10.1086/588279. S2CID 1953694.
  81. ^ Vogt, Steven S.; Marcy, Geoffrey W.; Butler, R. Paul; Apps, Kevin (2000). "Six New Planets from the Keck Precision Velocity Survey". The Astrophysical Journal. 536 (2): 902–914. arXiv:astro-ph/9911506. Bibcode:2000ApJ...536..902V. doi:10.1086/308981. S2CID 119375519.
  82. ^ Meschiari, Stefano; Laughlin, Gregory; Vogt, Steven S.; Butler, R. Paul; Rivera, Eugenio J.; Haghighipour, Nader; Jalowiczor, Peter (2011). "The Lick-Carnegie Survey: Four New Exoplanet Candidates". The Astrophysical Journal. 727 (2): 117. arXiv:1011.4068. Bibcode:2011ApJ...727..117M. doi:10.1088/0004-637X/727/2/117. S2CID 59065004.
  83. ^ Liu, Yu-Juan; Sato, Bun'ei; Zhao, Gang; Ando, Hiroyasu (2009). "A planetary companion orbiting the intermediate-mass G Giant HD 173416". Research in Astronomy and Astrophysics. 9 (1): 1–4. Bibcode:2009RAA.....9....1L. doi:10.1088/1674-4527/9/1/001. S2CID 250679097.
  84. ^ Muterspaugh, Matthew W.; Lane, Benjamin F.; Kulkarni, S. R.; Konacki, Maciej; Burke, Bernard F.; Colavita, M. M.; Shao, M.; Hartkopf, William I.; Boss, Alan P.; Williamson, M. (2010). "The Phases Differential Astrometry Data Archive. V. Candidate Substellar Companions to Binary Systems". The Astronomical Journal. 140 (6): 1657–1671. arXiv:1010.4048. Bibcode:2010AJ....140.1657M. doi:10.1088/0004-6256/140/6/1657. S2CID 59585356.
  85. ^ Zucker, S.; Naef, D.; Latham, D. W.; Mayor, M.; Mazeh, T.; Beuzit, J. L.; Drukier, G.; Perrier-Bellet, C.; Queloz, D.; Sivan, J. P.; Torres, G.; Udry, S. (2002). "A Planet Candidate in the Stellar Triple System HD 178911". The Astrophysical Journal. 568 (1): 363–368. arXiv:astro-ph/0111550. Bibcode:2002ApJ...568..363Z. doi:10.1086/338892. S2CID 16548934.
  86. ^ Alonso, Roi; Brown, Timothy M.; Torres, Guillermo; Latham, David W.; Sozzetti, Alessandro; Mandushev, Georgi; Belmonte, Juan A.; Charbonneau, David; Deeg, Hans J.; Dunham, Edward W.; O'Donovan, Francis T.; Stefanik, Robert P. (2004). "TrES-1: The Transiting Planet of a Bright K0 V Star". The Astrophysical Journal. 613 (2): L153–L156. arXiv:astro-ph/0408421. Bibcode:2004ApJ...613L.153A. doi:10.1086/425256. S2CID 8940599.
  87. ^ Dittmann, Jason A.; Close, Laird M.; Green, Elizabeth M.; Fenwick, Mike (2009). "A TENTATIVE DETECTION OF A STARSPOT DURING CONSECUTIVE TRANSITS OF AN EXTRASOLAR PLANET FROM THE GROUND: NO EVIDENCE OF A DOUBLE TRANSITING PLANET SYSTEM AROUND TrES-1". The Astrophysical Journal. 701 (1): 756–763. arXiv:0906.4320. Bibcode:2009ApJ...701..756D. doi:10.1088/0004-637X/701/1/756. S2CID 16254932.
  88. ^ Pollacco, D.; Skillen, I.; Collier Cameron, A.; Loeillet, B.; Stempels, H. C.; Bouchy, F.; Gibson, N. P.; Hebb, L.; Hébrard, G.; Joshi, Y. C.; McDonald, I.; Smalley, B.; Smith, A. M. S.; Street, R. A.; Udry, S.; West, R. G.; Wilson, D. M.; Wheatley, P. J.; Aigrain, S.; Alsubai, K.; Benn, C. R.; Bruce, V. A.; Christian, D. J.; Clarkson, W. I.; Enoch, B.; Evans, A.; Fitzsimmons, A.; Haswell, C. A.; Hellier, C.; Hickey, S.; Hodgkin, S. T.; Horne, K.; Hrudková, M.; Irwin, J.; Kane, S. R.; Keenan, F. P.; Lister, T. A.; Maxted, P.; Mayor, M.; Moutou, C.; Norton, A. J.; Osborne, J. P.; Parley, N.; Pont, F.; Queloz, D.; Ryans, R.; Simpson, E. (2008). "WASP-3b: a strongly irradiated transiting gas-giant planet". Monthly Notices of the Royal Astronomical Society. 385 (3): 1576–1584. arXiv:0711.0126. Bibcode:2008MNRAS.385.1576P. doi:10.1111/j.1365-2966.2008.12939.x. S2CID 2317308.
  89. ^ Maciejewski, G.; Niedzielski, A.; Wolszczan, A.; Nowak, G.; Neuhäuser, R.; Winn, J. N.; Deka, B.; Adamów, M.; Górecka, M.; Fernández, M.; Aceituno, F. J.; Ohlert, J.; Errmann, R.; Seeliger, M.; Dimitrov, D.; Latham, D. W.; Esquerdo, G. A.; McKnight, L.; Holman, M. J.; Jensen, E. L. N.; Kramm, U.; Pribulla, T.; Raetz, St.; Schmidt, T. O. B.; Ginski, Ch.; Mottola, S.; Hellmich, S.; Adam, Ch.; Gilbert, H.; Mugrauer, M.; Saral, G.; Popov, V.; Raetz, M. (2013). "Constraints on a Second Planet in the Wasp-3 System". The Astronomical Journal. 146 (6): 147. arXiv:1309.6733. Bibcode:2013AJ....146..147M. doi:10.1088/0004-6256/146/6/147. S2CID 17255900.
  90. ^ Latham, David W.; Borucki, William J.; Koch, David G.; Brown, Timothy M.; Buchhave, Lars A.; Basri, Gibor; Batalha, Natalie M.; Caldwell, Douglas A.; Cochran, William D.; Dunham, Edward W.; Fűrész, Gabor; Gautier, Thomas N.; Geary, John C.; Gilliland, Ronald L.; Howell, Steve B.; Jenkins, Jon M.; Lissauer, Jack J.; Marcy, Geoffrey W.; Monet, David G.; Rowe, Jason F.; Sasselov, Dimitar D. (2010). "KEPLER-7b: A TRANSITING PLANET WITH UNUSUALLY LOW DENSITY". The Astrophysical Journal. 713 (2): L140–L144. arXiv:1001.0190. Bibcode:2010ApJ...713L.140L. doi:10.1088/2041-8205/713/2/L140. S2CID 55061694.
  91. ^ Jenkins, Jon M.; Borucki, William J.; Koch, David G.; Marcy, Geoffrey W.; Cochran, William D.; Welsh, William F.; Basri, Gibor; Batalha, Natalie M.; Buchhave, Lars A.; Brown, Timothy M.; Caldwell, Douglas A.; Dunham, Edward W.; Endl, Michael; Fischer, Debra A.; Gautier, Thomas N.; Geary, John C.; Gilliland, Ronald L.; Howell, Steve B.; Isaacson, Howard; Johnson, John Asher; Latham, David W.; Lissauer, Jack J.; Monet, David G.; Rowe, Jason F.; Sasselov, Dimitar D.; Howard, Andrew W.; MacQueen, Phillip; Orosz, Jerome A.; Chandrasekaran, Hema; Twicken, Joseph D.; Bryson, Stephen T.; Quintana, Elisa V.; Clarke, Bruce D.; Li, Jie; Allen, Christopher; Tenenbaum, Peter; Wu, Hayley; Meibom, Søren; Klaus, Todd C.; Middour, Christopher K.; Cote, Miles T.; McCauliff, Sean; Girouard, Forrest R.; Gunter, Jay P.; Wohler, Bill; Hall, Jennifer R.; Ibrahim, Khadeejah; Kamal Uddin, AKM; Wu, Michael S.; Bhavsar, Paresh A.; Van Cleve, Jeffrey; Pletcher, David L.; Dotson, Jessie L.; Haas, Michael R. (2010). "DISCOVERY AND ROSSITER-McLAUGHLIN EFFECT OF EXOPLANET KEPLER-8b". The Astrophysical Journal. 724 (2): 1108–1119. arXiv:1001.0416. Bibcode:2010ApJ...724.1108J. doi:10.1088/0004-637X/724/2/1108. S2CID 13181333.
  92. ^ Gautier, Thomas N.; Charbonneau, David; Rowe, Jason F.; Marcy, Geoffrey W.; Isaacson, Howard; Torres, Guillermo; Fressin, Francois; Rogers, Leslie A.; Désert, Jean-Michel; Buchhave, Lars A.; Latham, David W.; Quinn, Samuel N.; Ciardi, David R.; Fabrycky, Daniel C.; Ford, Eric B.; Gilliland, Ronald L.; Walkowicz, Lucianne M.; Bryson, Stephen T.; Cochran, William D.; Endl, Michael; Fischer, Debra A.; Howell, Steve B.; Horch, Elliott P.; Barclay, Thomas; Batalha, Natalie; Borucki, William J.; Christiansen, Jessie L.; Geary, John C.; Henze, Christopher E.; Holman, Matthew J.; Ibrahim, Khadeejah; Jenkins, Jon M.; Kinemuchi, Karen; Koch, David G.; Lissauer, Jack J.; Sanderfer, Dwight T.; Sasselov, Dimitar D.; Seager, Sara; Silverio, Kathryn; Smith, Jeffrey C.; Still, Martin; Stumpe, Martin C.; Tenenbaum, Peter; Van Cleve, Jeffrey (2012). "Kepler-20: A Sun-Like Star with Three Sub-Neptune Exoplanets and Two Earth-Size Candidates". The Astrophysical Journal. 749 (1): 15. arXiv:1112.4514. Bibcode:2012ApJ...749...15G. doi:10.1088/0004-637X/749/1/15. S2CID 18765025.
  93. ^ Fressin, Francois; Torres, Guillermo; Rowe, Jason F.; Charbonneau, David; Rogers, Leslie A.; Ballard, Sarah; Batalha, Natalie M.; Borucki, William J.; Bryson, Stephen T.; Buchhave, Lars A.; Ciardi, David R.; Désert, Jean-Michel; Dressing, Courtney D.; Fabrycky, Daniel C.; Ford, Eric B.; Gautier III, Thomas N.; Henze, Christopher E.; Holman, Matthew J.; Howard, Andrew; Howell, Steve B.; Jenkins, Jon M.; Koch, David G.; Latham, David W.; Lissauer, Jack J.; Marcy, Geoffrey W.; Quinn, Samuel N.; Ragozzine, Darin; Sasselov, Dimitar D.; Seager, Sara; Barclay, Thomas; Mullally, Fergal; Seader, Shawn E.; Still, Martin; Twicken, Joseph D.; Thompson, Susan E.; Uddin, Kamal (2011). "Two Earth-sized planets orbiting Kepler-20". Nature. 482 (7384): 195–198. arXiv:1112.4550. Bibcode:2012Natur.482..195F. doi:10.1038/nature10780. PMID 22186831. S2CID 3182266.
  94. ^ a b Borucki, William J.; et al. (18 April 2013). "Kepler-62: A Five-Planet System with Planets of 1.4 and 1.6 Earth Radii in the Habitable Zone". Science Express. 340 (6132): 587–90. arXiv:1304.7387. Bibcode:2013Sci...340..587B. doi:10.1126/science.1234702. hdl:1721.1/89668. PMID 23599262. S2CID 21029755. Archived from the original on 2 May 2022. Retrieved 18 March 2022.
  95. ^ Johnson, Michele; Harrington, J.D. (18 April 2013). "NASA's Kepler Discovers Its Smallest 'Habitable Zone' Planets to Date". NASA. Archived from the original on 8 May 2020. Retrieved 18 March 2022.
  96. ^ Grant, Andrew (18 April 2013). "Most Earthlike planets yet seen bring Kepler closer to its holy grail". ScienceNews.org. Archived from the original on 21 April 2013. Retrieved 19 April 2013.
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