Astronomy:Epsilon Indi

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Short description: Star system in the constellation of Indus
Epsilon Indi
Indus constellation map.svg
Red circle.svg
Location of ε Indi (circled)
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Indus
Right ascension  22h 03m 21.65363s[1]
Declination −56° 47′ 09.5228″[1]
Apparent magnitude (V) 4.8310±0.0005[2]
Characteristics
Spectral type K5V + T1 + T6[3]
U−B color index 1.00[4]
B−V color index 1.056±0.016[2]
Astrometry
ε Ind A
Radial velocity (Rv)−40.43±0.13[1] km/s
Proper motion (μ) RA: 3,966.661(86)[1] mas/yr
Dec.: −2,536.192(92)[1] mas/yr
Parallax (π)274.8431 ± 0.0956[1] mas
Distance11.867 ± 0.004 ly
(3.638 ± 0.001 pc)
Absolute magnitude (MV)6.89[5]
ε Ind Ba/Bb
Parallax (π)270.6580 ± 0.6896[6] mas
Distance12.05 ± 0.03 ly
(3.695 ± 0.009 pc)
Orbit[7]
Primaryε Ind Ba
Companionε Ind Bb
Period (P)11.0197 ± 0.0076 yr
Semi-major axis (a)661.58 ± 0.37 mas
(2.4058 ± 0.0040 au)
Eccentricity (e)0.54042 ± 0.00063
Inclination (i)77.082 ± 0.032°
Longitude of the node (Ω)147.959 ± 0.023°
Argument of periastron (ω)
(secondary)		328.27 ± 0.12°
Details[8]
ε Ind A
Mass0.754±0.038[3] M☉
Radius0.711±0.005 R☉
Luminosity0.21±0.02 L☉
Surface gravity (log g)4.63±0.01 cgs
Temperature4,649±84 K
Metallicity [Fe/H]−0.13±0.06 dex
Rotation35.732+0.006
−0.003 days[9]
Rotational velocity (v sin i)2.00 km/s
Age3.5+0.8
−1.0[7] Gyr
ε Ind Ba/Bb
MassBa: 66.92±0.36 MJup
Bb: 53.25±0.29[7] MJup
RadiusBa: ~0.080–0.081 R☉
Bb: ~0.082–0.083[10] R☉
LuminosityBa: 0.00002037(81) L☉
Bb: 0.00000597(27)[7] L☉
Surface gravity (log g)Ba: 5.43–5.45
Bb: 5.27–5.33[10] cgs
TemperatureBa: 1,352–1,385 K
Bb: 976–1,011[10] K
Other designations
UGP 544, ε Ind, CD−57°8464, CPD−57°10015, FK5 825, GJ 845, HD 209100, HIP 108870, HR 8387, SAO 247287, LHS 67[11]
Database references
SIMBADThe system
A
Bab
Bab (as X-ray source)

Epsilon Indi, Latinized from ε Indi, is a star system located at a distance of approximately 12 light-years from Earth in the southern constellation of Indus. The star has an orange hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.83.[2] It consists of a K-type main-sequence star, ε Indi A, and two brown dwarfs, ε Indi Ba and ε Indi Bb, in a wide orbit around it.[12] The brown dwarfs were discovered in 2003. ε Indi Ba is an early T dwarf (T1) and ε Indi Bb a late T dwarf (T6) separated by 0.6 arcseconds, with a projected distance of 1460 AU from their primary star.

ε Indi A has one known planet, ε Indi Ab, with a mass of 3.3 Jupiter masses in an elliptical orbit with a period of about 45 years. ε Indi Ab is the second-closest Jovian exoplanet, after ε Eridani b. The ε Indi system provides a benchmark case for the study of the formation of gas giants and brown dwarfs.[9]

Observation

Epsilon Indi with SkyMapper and a Hubble NICMOS image of the brown dwarf binary

The constellation Indus (the Indian) first appeared in Johann Bayer's celestial atlas Uranometria in 1603. The 1801 star atlas Uranographia, by German astronomer Johann Elert Bode, places ε Indi as one of the arrows being held in the left hand of the Indian.[13]

In 1847, Heinrich Louis d'Arrest compared the position of this star in several catalogues dating back to 1750, and discovered that it possessed a measureable proper motion. That is, he found that the star had changed position across the celestial sphere over time.[14] In 1882–3, the parallax of ε Indi was measured by astronomers David Gill and William L. Elkin at the Cape of Good Hope. They derived a parallax estimate of 0.22 ± 0.03 arcseconds.[15] In 1923, Harlow Shapley of the Harvard Observatory derived a parallax of 0.45 arcseconds.[16]

In 1972, the Copernicus satellite was used to examine this star for the emission of ultraviolet laser signals. Again, the result was negative.[17] ε Indi leads a list, compiled by Margaret Turnbull and Jill Tarter of the Carnegie Institution in Washington, of 17,129 nearby stars most likely to have planets that could support complex life.[18]

The star is among five nearby paradigms as K-type stars of a type in a 'sweet spot' between Sun-analog stars and M stars for the likelihood of evolved life, per analysis of Giada Arney from NASA's Goddard Space Flight Center.[19]

Characteristics

ε Indi A is a main-sequence star of spectral type K5V. The star has only about three-fourths the mass of the Sun[20] and 71% of the Sun's radius.[8] Its surface gravity is slightly higher than the Sun's.[4] The metallicity of a star is the proportion of elements with higher atomic numbers than helium, being typically represented by the ratio of iron to hydrogen compared to the same ratio for the Sun; ε Indi A is found to have about 87% of the Sun's proportion of iron in its photosphere.[3]

The corona of ε Indi A is similar to the Sun, with an X-ray luminosity of 2×1027 ergs s−1 (2×1020 W) and an estimated coronal temperature of 2×106 K. The stellar wind of this star expands outward, producing a bow shock at a distance of 63 AU. Downstream of the bow, the termination shock reaches as far as 140 AU from the star.[21]

Position of Sun and α Centauri in Ursa Major as seen from ε Indi

This star has the third highest proper motion of any star visible to the unaided eye, after Groombridge 1830 and 61 Cygni,[22] and the ninth highest overall.[23] This motion will move the star into the constellation Tucana around 2640 AD.[24] ε Indi A has a space velocity relative to the Sun of 86 km/s,[4][note 1] which is unusually high for what is considered a young star.[25] It is thought to be a member of the ε Indi moving group of at least sixteen population I stars.[26] This is an association of stars that have similar space velocity vectors, and therefore most likely formed at the same time and location.[27] ε Indi will make its closest approach to the Sun in about 17,500 years when it makes perihelion passage at a distance of around 10.58 light-years (3.245 pc).[28]

As seen from ε Indi, the Sun is a 2.6-magnitude star in Ursa Major, near the bowl of the Big Dipper.[note 2]

Companions

Artist's conception of the Epsilon Indi system showing Epsilon Indi A and its brown-dwarf binary companions. The labels give the initial minimum measurement of the distance between Epsilon Indi A and the binary.

Brown dwarfs

In January 2003, astronomers announced the discovery of a brown dwarf with a mass of 40 to 60 Jupiter masses in orbit around ε Indi A with a projected separation on the sky of about 1,500 AU.[29][30] In August 2003, astronomers discovered that this brown dwarf was actually a binary brown dwarf, with an apparent separation of 2.1 AU and an orbital period of about 15 years.[10][31] Both brown dwarfs are of spectral class T; the more massive component, ε Indi Ba, is of spectral type T1–T1.5 and the less massive component, ε Indi Bb, of spectral type T6.[10] More recent parallax measurements with the Gaia spacecraft place the ε Indi B binary about 11,600 AU (0.183 lightyears) away from ε Indi A, along line of sight from Earth.[6]

Evolutionary models[32] have been used to estimate the physical properties of these brown dwarfs from spectroscopic and photometric measurements. These yield masses of 47 ± 10 and 28 ± 7 times the mass of Jupiter, and radii of 0.091 ± 0.005 and 0.096 ± 0.005 solar radii, for ε Indi Ba and ε Indi Bb, respectively.[33] The effective temperatures are 1300–1340 K and 880–940 K, while the log g (cm s−1) surface gravities are 5.50 and 5.25, and their luminosities are 1.9 × 10−5 and 4.5 × 10−6 the luminosity of the Sun. They have an estimated metallicity of [M/H] = –0.2.[10]

Planetary system

The Epsilon Indi A planetary system[34]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(years) 		Eccentricity Inclination Radius
b 2.96+0.41
−0.38 MJ 		11.08+1.07
−0.74 		42.92+6.38
−4.09 		0.42±0.04 84.41+9.36
−9.94° 		—

Measurements of the radial velocity of Epsilon Indi by Endl et al. (2002)[35] appeared to show a trend that indicated a planetary companion with an orbital period of more than 20 years. A substellar object with minimum mass of 1.6 Jupiter masses and orbital separation of roughly 6.5 AU (a Jupiter-analogue) was within the parameters of the highly approximate data.

A visual search using the ESO's Very Large Telescope found one potential candidate. However, a subsequent examination by the Hubble Space Telescope NICMOS showed that this was a background object.[36] As of 2009, a search for an unseen companion at 4 μm failed to detect an orbiting object. These observations further constrained the hypothetical object to be 5–20 times the mass of Jupiter, orbiting between 10 and 20 AU and have an inclination of more than 20°. Alternatively, it may be an exotic stellar remnant.[37]

A longer study of radial (to or from Earth) velocity, using the HARPS Echelle spectrometer, to follow up on Endl's findings, was published in a paper by M. Zechmeister et al. in 2013. The findings confirm that, quoting the paper, "ε Ind A has a steady long-term trend still explained by a planetary companion".[38] This refined the radial-velocity trend observed and indicated a planetary companion with an orbital period greater than 30 years. A gas giant with a minimum mass of 0.97 Jupiter masses and a minimal orbital separation of roughly 9.0 AU could explain the observed trend.[note 3] 9.0 AU is about the same distance out as Saturn. This does not quite qualify the planet as a true Jupiter analogue because it orbits considerably further out than 5.0 AU.[38] Not only does it orbit further out, but ε Indi A is also dimmer than the Sun, so it would only receive about the same amount of energy per square meter as Uranus does from the Sun. The radial-velocity trend was observed through all the observations so far taken using the HARPS spectrometer but due to the long time period predicted for just one orbit of the object around ε Indi A, more than 30 years, the phase coverage was not yet complete.[38]

In March 2018, a preprint was posted to arXiv that confirmed the existence of Epsilon Indi Ab using radial velocity measurements.[39] In December 2019, the confirmation of this planet, along with updated parameters from both radial velocity and astrometry, was published by Fabo Feng et al. in Monthly Notices of the Royal Astronomical Society. They show that the orbit is slightly eccentric, with a semi-major axis of about 11.6 AU and an eccentricity of about 0.26. The mass of the planet is 3.25 Jupiter masses, and its orbital period is about 45 years.[9] At a separation of 3.3 arcseconds from its host star, direct imaging of this planet using the James Webb Space Telescope is planned.[40]

No excess infrared radiation that would indicate a debris disk has been detected around ε Indi.[41] Such a debris disk could be formed from the collisions of planetesimals that survive from the early period of the star's protoplanetary disk.

See also

Notes

  1. ↑ The space velocity components are: U = −77; V = −38, and W = +4. This yields a net space velocity of [math]\displaystyle{ \begin{smallmatrix}\sqrt{77^2\ +\ 38^2\ +\ 4^2}\ =\ 86\end{smallmatrix} }[/math] km/s.
  2. ↑ From ε Indi the Sun would appear on the diametrically opposite side of the sky at the coordinates RA= 10h 03m 21s, Dec=56° 47′ 10″, which is located near Beta Ursae Majoris. The absolute magnitude of the Sun is 4.8, so, at a distance of 3.63 parsecs, the Sun would have an apparent magnitude [math]\displaystyle{ \begin{smallmatrix}m\ =\ M_v\ +\ 5\cdot((\log_{10}\ 3.63)\ -\ 1)\ =\ 2.6\end{smallmatrix} }[/math].
  3. ↑ Kepler's Third Law, assuming a circular orbit gives [math]\displaystyle{ \begin{smallmatrix}\frac{4 \pi^2}{T^2} = \frac{G (M+m)}{R^3}\end{smallmatrix} }[/math]. The mass and period are known from the paper,[38] so the semimajor axis can be calculated using [math]\displaystyle{ \begin{smallmatrix}R = \sqrt[3]{\frac{G(M+m)T^2}{4\pi^2}}\end{smallmatrix} }[/math] .

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  2. ↑ 2.0 2.1 2.2 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V. http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL. 
  3. ↑ 3.0 3.1 3.2 Demory, Brice-Olivier; Ségransan, Damien; Forveille, Thierry; Queloz, Didier; Beuzit, Jean-Luc; Delfosse, Xavier; Di Folco, Emmanuel; Kervella, Pierre et al. (October 2009). "Mass-radius relation of low and very low-mass stars revisited with the VLTI". Astronomy and Astrophysics 505 (1): 205–215. doi:10.1051/0004-6361/200911976. Bibcode: 2009A&A...505..205D. 
  4. ↑ 4.0 4.1 4.2 Kollatschny, W. (1980). "A model atmosphere of the late type dwarf Epsilon INDI". Astronomy and Astrophysics 86 (3): 308–314. Bibcode: 1980A&A....86..308K. 
  5. ↑ Jimenez, Raul; Flynn, Chris; MacDonald, James; Gibson, Brad K. (March 2003). "The Cosmic Production of Helium". Science 299 (5612): 1552–1555. doi:10.1126/science.1080866. PMID 12624260. Bibcode: 2003Sci...299.1552J. 
  6. ↑ 6.0 6.1 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  7. ↑ 7.0 7.1 7.2 7.3 Chen, Minghan; Li, Yiting; Brandt, Timothy D.; Dupuy, Trent J.; Cardoso, Cátia V.; McCaughrean, Mark J. (2022). "Precise Dynamical Masses of ε Indi Ba and Bb: Evidence of Slowed Cooling at the L/T Transition". The Astronomical Journal 163 (6): 288. doi:10.3847/1538-3881/ac66d2. Bibcode: 2022AJ....163..288C. 
  8. ↑ 8.0 8.1 Rains, Adam D. et al. (April 2020). "Precision angular diameters for 16 southern stars with VLTI/PIONIER". Monthly Notices of the Royal Astronomical Society 493 (2): 2377–2394. doi:10.1093/mnras/staa282. Bibcode: 2020MNRAS.493.2377R. 
  9. ↑ 9.0 9.1 9.2 Feng, Fabo; Anglada-Escudé, Guillem; Tuomi, Mikko; Jones, Hugh R. A.; Chanamé, Julio; Butler, Paul R.; Janson, Markus (14 October 2019), "Detection of the nearest Jupiter analog in radial velocity and astrometry data", Monthly Notices of the Royal Astronomical Society 490 (4): 5002–5016, doi:10.1093/mnras/stz2912, Bibcode: 2019MNRAS.490.5002F 
  10. ↑ 10.0 10.1 10.2 10.3 10.4 10.5 King, R. R. et al. (February 2010), "ɛ Indi Ba, Bb: a detailed study of the nearest known brown dwarfs", Astronomy and Astrophysics 510: A99, doi:10.1051/0004-6361/200912981, Bibcode: 2010A&A...510A..99K, http://goedoc.uni-goettingen.de/goescholar/bitstream/handle/1/9686/aa12981-09.pdf?sequence=2, "However, it seems that derivations of the mass of cool brown dwarfs are uncertain even where estimates of the effective temperature, surface gravity, and luminosity exist." 
  11. ↑ "SIMBAD Query Result: LHS 67 -- High proper-motion Star". Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-id?Ident=epsilon%20indi. 
  12. ↑ Smith, Verne V.; Tsuji, Takashi; Hinkle, Kenneth H.; Cunha, Katia; Blum, Robert D.; Valenti, Jeff A.; Ridgway, Stephen T.; Joyce, Richard R. et al. (2003). "High-resolution infrared spectroscopy of the brown dwarf ε Indi Ba". The Astrophysical Journal Letters 599 (2): L107–L110. doi:10.1086/381248. Bibcode: 2003ApJ...599L.107S. 
  13. ↑ Scholz, Ralf-Dieter; McCaughrean, Mark (2003-01-13). "Discovery of Nearest Known Brown Dwarf". ESO. http://www.eso.org/public/outreach/press-rel/pr-2003/pr-01-03.html. 
  14. ↑ D'Arrest, M. (1847). "On proper motion of ε Indi". Monthly Notices of the Royal Astronomical Society 8: 16. doi:10.1093/mnras/8.1.16. Bibcode: 1847MNRAS...8...16D. 
  15. ↑ Callandreau, O. (1886). "Revue des publications astronomiques. Heliometer determinations of Stellar parallax, in the southern hemisphere, by David Gill and W. L. Elkin" (in fr). Bulletin Astronomique 2 (1): 42–44. Bibcode: 1885BuAsI...2...42C. 
  16. ↑ Shapley, Harlow (1923). "Epsilon Indi". Harvard College Observatory Bulletin 789 (789): 2. Bibcode: 1923BHarO.789Q...2S. 
  17. ↑ Lawton, A. T. (1975). "CETI from Copernicus". Spaceflight 17: 328–330. Bibcode: 1975SpFl...17..328L. 
  18. ↑ Stahl, Jason (January 2007). "20 Things You Didn't Know About... Aliens". Discover. http://www.discover.com/issues/jan-07/departments/20-things-aliens/. 
  19. ↑ Bill Steigerwald (22 February 2019). ""Goldilocks" Stars May be "Just Right" for Finding Habitable Worlds". NASA. https://www.nasa.gov/feature/goddard/2019/k-star-advantage. "'I find that certain nearby K stars like 61 Cyg A/B, Epsilon Indi, Groombridge 1618, and HD 156026 may be particularly good targets for future biosignature searches,' said Arney." 
  20. ↑ "The 100 nearest star systems". Georgia State University. January 1, 2012. http://www.astro.gsu.edu/RECONS/TOP100.posted.htm. 
  21. ↑ Müller, Hans-Reinhard; Zank, Gary P. (2001). "Modeling the Interstellar Medium-Stellar Wind Interactions of λ Andromedae and ε Indi". The Astrophysical Journal 551 (1): 495–506. doi:10.1086/320070. Bibcode: 2001ApJ...551..495M. 
  22. ↑ Weaver, Harold F. (1947). "The Visibility of Stars Without Optical Aid". Publications of the Astronomical Society of the Pacific 59 (350): 232–243. doi:10.1086/125956. Bibcode: 1947PASP...59..232W. 
  23. ↑ Staff (2007-05-04). "High Proper Motion Stars: Interesting Areas to View". ESA. http://www.rssd.esa.int/index.php?project=HIPPARCOS&page=areas. 
  24. ↑ Patrick Moore; Robin Rees (2014). Patrick Moore's Data Book of Astronomy. Cambridge: Cambridge University Press. p. 296. ISBN 978-1-139-49522-6. https://books.google.com/books?id=2FNfjWKBZx8C. 
  25. ↑ Rocha-Pinto, Helio J.; Maciel, Walter J.; Castilho, Bruno V. (2001). "Chromospherically Young, Kinematically Old Stars". Astronomy and Astrophysics 384 (3): 912–924. doi:10.1051/0004-6361:20011815. Bibcode: 2002A&A...384..912R. 
  26. ↑ Eggen, O. J. (1971). "The zeta Herculis, sigma Puppis, ε Indi, and eta Cephei Groups of Old Disk Population Stars". Publications of the Astronomical Society of the Pacific 83 (493): 251–270. doi:10.1086/129119. Bibcode: 1971PASP...83..251E. 
  27. ↑ Kollatschny, W. (1980). "A model atmosphere of the late type dwarf Epsilon INDI". Astronomy and Astrophysics 86 (3): 308–314. Bibcode: 1980A&A....86..308K. 
  28. ↑ Bailer-Jones, C. A. L. (March 2015), "Close encounters of the stellar kind", Astronomy & Astrophysics 575: 13, doi:10.1051/0004-6361/201425221, A35, Bibcode: 2015A&A...575A..35B. 
  29. ↑ Scholz, Ralf-Dieter; McCaughrean, Mark (2003-01-13). "Discovery of Nearest Known Brown Dwarf: Bright Southern Star Epsilon Indi Has Cool, Substellar Companion". European Southern Observatory. http://www.eso.org/public/outreach/press-rel/pr-2003/pr-01-03.html. 
  30. ↑ Scholz, R.-D.; McCaughrean, M. J.; Lodieu, N.; Kuhlbrodt, B. (February 2003). "ε Indi B: A new benchmark T dwarf". Astronomy and Astrophysics 398 (3): L29–L33. doi:10.1051/0004-6361:20021847. Bibcode: 2003A&A...398L..29S. 
  31. ↑ Volk, K.; Blum, R.; Walker, G.; Puxley, P. (2003). "epsilon Indi B". IAU Circular (IAU) 8188 (8188): 2. Bibcode: 2003IAUC.8188....2V. 
  32. ↑ E.g., Baraffe, I.; Chabrier, G.; Barman, T.; Allard, F.; Hauschildt, P. H. (May 2003). "Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 209458". Astronomy and Astrophysics 402 (2): 701–712. doi:10.1051/0004-6361:20030252. Bibcode: 2003A&A...402..701B. 
  33. ↑ McCaughrean, M. J. (January 2004). "ε Indi Ba, Bb: The nearest binary brown dwarf". Astronomy and Astrophysics 413 (3): 1029–1036. doi:10.1051/0004-6361:20034292. Bibcode: 2004A&A...413.1029M. 
  34. ↑ Feng, Fabo et al. (July 2023). "Revised orbits of the two nearest Jupiters". Monthly Notices of the Royal Astronomical Society 525 (1): 607–619. doi:10.1093/mnras/stad2297. Bibcode: 2023MNRAS.525..607F. 
  35. ↑ Endl, M.; Kürster, M.; Els, S.; Hatzes, A. P.; Cochran, W. D.; Dennerl, K.; Döbereiner, S. (2002). "The planet search program at the ESO Coudé Echelle spectrometer. III. The complete Long Camera survey results". Astronomy and Astrophysics 392 (2): 671–690. doi:10.1051/0004-6361:20020937. Bibcode: 2002A&A...392..671E. 
  36. ↑ Geißler, K.; Kellner, S.; Brandner, W.; Masciadri, E.; Hartung, M.; Henning, T.; Lenzen, R.; Close, L. et al. (2007). "A direct and differential imaging search for sub-stellar companions to epsilon Indi A". Astronomy and Astrophysics 461 (2): 665–668. doi:10.1051/0004-6361:20065843. Bibcode: 2007A&A...461..665G. 
  37. ↑ Janson, M. (August 10, 2009). "Imaging search for the unseen companion to ε Ind A – improving the detection limits with 4 μm observations". Monthly Notices of the Royal Astronomical Society 399 (1): 377–384. doi:10.1111/j.1365-2966.2009.15285.x. Bibcode: 2009MNRAS.399..377J. 
  38. ↑ 38.0 38.1 38.2 38.3 Zechmeister, M.; Kürster, M; Endl, M.; Lo Curto, G.; Hartman, H.; Nilsson, H.; Henning, T.; Hatzes, A. et al. (April 2013). "The planet search programme at the ESO CES and HARPS. IV. The search for Jupiter analogues around solar-like stars". Astronomy and Astrophysics 552: 62. doi:10.1051/0004-6361/201116551. Bibcode: 2013A&A...552A..78Z. 
  39. ↑ Feng, Fabo; Tuomi, Mikko; Jones, Hugh R. A. (23 March 2018). "Detection of the closest Jovian exoplanet in the Epsilon Indi triple system". arXiv:1803.08163 [astro-ph.EP].
  40. ↑ "A direct detection of the closest Jupiter analog with JWST/MIRI". STScI. https://www.stsci.edu/jwst/science-execution/program-information.html?id=2243. "We will collect the first direct images of a radial velocity planet, by targeting Eps Indi Ab with JWST/MIRI. [...] Our simulations confirm that we will detect Eps Indi Ab's thermal emission at high confidence, regardless of its cloud properties or thermal evolution." 
  41. ↑ Trilling, D. E. (February 2008). "Debris Disks around Sun-like Stars". The Astrophysical Journal 674 (2): 1086–1105. doi:10.1086/525514. Bibcode: 2008ApJ...674.1086T. http://www.iop.org/EJ/article/0004-637X/674/2/1086/72640.html. 

External links

Coordinates: Sky map 22h 03m 21.6571s, −56° 47′ 09.514″



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