40 Eridan or Omicron² Eridanus is a triple star system close to the Earth in the constellation Eridanus . It is located at a distance of 16.45 St. years (5.04 pc ) from the sun .
40 Eridan ABC | |||
---|---|---|---|
Star | |||
Observational data ( Epoch J2000.0 ) | |||
Type of | Triple star | ||
Right ascension | |||
Declination | |||
Distance | 16.45 sv. years (5.04 pc ) [1] | ||
Visible magnitude ( V ) | 4.42 [1] / 9.52 / 11.17 | ||
Constellation | Eridan | ||
Astrometry | |||
Radial velocity ( R v ) | -42.2 [2] km / s | ||
Proper motion (μ) | RA: -2239.71 [2] mas per year Dec: -3420.34 [2] mas per year | ||
Parallax (π) | 198.26 ± 0.84 [2] mas | ||
Absolute magnitude (V) | 5.92 [1] / 11.01 / 12.66 | ||
Specifications | |||
Spectral class | K1V [2] / DA4 / M4,5Ve | ||
Color Indicator ( B - V ) | 0.82 [1] / 0.03 / 1.67 | ||
Color Index ( U - B ) | 0.45 [1] / -0.68 / 0.83 | ||
physical characteristics | |||
Weight | 0.84 / 0.50 / 0.20 M ☉ | ||
Radius | 0.81 / 0.014 / 0.31 R ☉ | ||
Temperature | 5300/16500/3100 K | ||
Luminosity | 0.46 / 0.013 / 0.008 L ☉ | ||
| |||
Information in databases | |||
SIMBAD | data | ||
ARICNS | data | ||
Sources: [2] [1] | |||
In 1783, William Herschel, for the first time, allowed a couple of 40 Eridani BC separately [3] . Then the pair was observed by William Struve in 1825 and Otto Struve in 1851 [4] [5] .
Content
Characteristics
40 Eridan A
The brightest component of the Eridan A system 40 is the orange dwarf of the spectral class K1V, visible to the naked eye. The metallicity of the [Fe / H] star is −0.19, which is 65% of the metallicity of the Sun [6] . Age - 5.6 billion years [7] .
The star 40 Eridani A has the traditional name Keid .
40 Eridan A b
In 2017, at the conference on extremely accurate radial velocity measurements in Pennsylvania, Matías Díaz from the University of Chile indicated that 40 Eridani A had a signal with a period of about 42.37 days, which could be caused by the influence of a planet with a mass of 8 Earth masses the semi-axis of the orbit is 0.21 AU. It is possible that the periodic oscillations are associated with the stellar activity of the orange dwarf, the rotation period of which around the axis is estimated at 38 days, which is close enough to the observed oscillation period [8] .
According to the calculations of scientists from the University of Florida, the super-earth 40 Eridan A b weighing 8.47 ± 0.47 Earth mass is in the habitable zone . Other sources, however, claim that the planet has a temperature regime of Mercury [9] [ specify the link (already 94 days) ] .
The planet orbits around the parent star in 42.38 ± 0.01 days, the eccentricity of the orbit is 0.04 + 0.05 / –0.03 [10] [11] .
40 Eridanus BC
The 40 Eridanes BC pair revolves around the main star of the 40 Eridani A system for ~ 8 thousand years at a distance of 400 astronomical units.
40 Eridan B
40 Eridani B is a white dwarf that was determined in 1910 . It is the third open white dwarf after Sirius B and Procyon B and the first white dwarf discovered in a triple star system. The magnitude of +9.52 m . Although the temperature on its surface reaches 17,000 ° C, the luminosity turned out to be very weak, since the star across is smaller than the Earth (0.014 the radius of the Sun ). The mass of a white dwarf is 0.5 times the mass of the sun.
40 Eridan C
40 Eridanus C is a red dwarf of spectral class M4.5 Ve with a mass of 0.2 solar masses and a radius of 0.31 of the radius of the Sun. It belongs to the class of flare stars and has the designation DY Eridanus . The orbital period of 40 Eridani C around the white dwarf is 252.1 years, the semi-major axis of the orbit is ~ 35 a. e. , inclination ( i ) - 108.9 °, eccentricity ( e ) - 0.41.
Planetary system
In 2018, a planet with a minimum mass of 8.47 ± 0.47 Earth masses was detected, rotating in the orbit of 40 Eridan A [12] . The planet has an orbit of 42 days and is largely within the habitable zone , receiving 9 times more stellar flow than the Earth [13] . The disk of the star 40 Eridani A in the sky of the planet 40 Eridani A b would be about three times larger than the disk of the Sun in the sky of the Earth, and a pair of 40 Eridane Sun would be insoluble with the naked eye and shine like one very weak asterisk.
Planet | Weight ( M ⊕ ) | Big axis orbits ( a. e ) | Period of treatment ( days ) | Eccentricity orbits | Orbit inclination | Radius |
---|---|---|---|---|---|---|
b | 8.47 ± 0.47 | 0,22446 ± 0,00004 | 42.38 ± 0.01 | 0.04 +0.05 −0.03 | - | - |
Star's Neighborhood
The following star systems are within 10 light-years from Eridan's 40:
Star | Spectral class | Distance, sv. years old |
LP 656-38 | M3.5 V | 3.8 |
BD-03 1123 | M1,5 V | 6.2 |
ε Eridani | K2 V | 6.4 |
LTT 17897 | M4 V | 8.1 |
LP 944-020 | M9 | 8.2 |
Tigarden Star | M6,5 V | 8.7 |
Luyten 730-18 AB | M3 V / M3 V-VI | 8.9 |
G 99-44 (Gliese 223.2 or WD 0552-041) | Dz9 | 9.1 |
Ross 614 AB | M4,5 Ve / M8 V | 9.1 |
Ross 47 | M4 V | 9.3 |
Gliese 229 | M1 Ve | 9.8 |
Fiction
- In the Star Trek universe , the 40 Eridane A system is the estimated location of the planet Vulcan , the home of the Vulcan race. Although in none of the television serials or movies the place where Vulcan is located is not named, and the book “ Star Trek: Star Charts ” [14] and Gene Roddenberry [15] point to this system. In addition, Commander Tucker's statement in Star Trek: Enterprise , which is Vulcan 16 light years away, confirms this view, since the distance from the Sun to Eridanus 40 is 16.45 ss . years old. [sixteen]
- In the novel “ Behind the Pass ” in the novel by Vladimir Savchenko , the Fifth Star Expedition discovered an anti-matter asteroid belt in the white dwarf system of the triple star Omega Eridanus (as in the text). Apparently, I mean 40 Eridani B.
- The last chapters of the novel by I. A. Efremov “Andromeda Nebula” are devoted to the preparation and sending of the thirty-eighth star expedition of earthlings, originally planned to the Omicron 2 Eridan system for the study of a white dwarf. The study of the latter seems so important to our descendants that sending a spaceship to this system is not rejected even after the appearance of more significant goals - the beginning of mastering two habitable planets orbiting Ahernn (α Eridanus ) and exploring an alien spaceship found not far from the Solar System .
- In the story “The Rat of the System” by Paul J. Macoule, the action takes place in Eridanus 40. The story uses the multiplicity of the system, the artificial intelligence apparatus is engaged in astroengineering: it works to change the orbit of the red dwarf and push it with the white dwarf .
- In William Keith 's novel The Black Matter (Star Aviation Carrier cycle), in system 40 of Eridani A, there is an Earth-like planet called Vulcan. This is a big rarity in space, since life on the surface of Vulcan is based on the same amino acids and sugars as life on Earth.
See also
- List of stars in the constellation Eridani
- List of nearby stars
Notes
- ↑ 1 2 3 4 5 6 ARICNS (English) . - 40 Eridane ABC in the ARICNS database. The appeal date is October 20, 2010.
- ↑ 1 2 3 4 5 6 SIMBAD (English) . - 40 Eridan ABC in SIMBAD database . The appeal date is October 20, 2010.
- ↑ Catalog of Double Stars (inaccessible link - history ) . , William Herschel, Philosophical Transactions of the Royal Society of London 75 (1785), pp. 40–126
- ↑ Astrometric study of four visual binaries , WD Heintz, Astronomical Journal 79 , # 7 (July 1974), pp. 819–825.
- ↑ van den Bos, WH “The Orbit and the Masses of 40 Eridani BC” // Bulletin of the Astronomical Institutes of the Netherlands, Vol. 3, p.128. 07/1926
- ↑ Cayrel de Strobel, G .; Hauck, B .; Francois, P .; Thevenin, F .; Friel, E .; Mermilliod, M .; Borde, S. A catalog of Fe / H determinations - 1991 edition (English) // Astronomy and Astrophysics . - EDP Sciences , 1992. - Vol. 95 - P. 273-336 . - . —Metallicity for component A
- ↑ Mamajek, Eric E .; Hillenbrand, Lynne A. Improved Age for Solar-Type Dwarfs Using Activity-Rotation Diagnostics (English) // The Astrophysical Journal : journal. - IOP Publishing , 2008. - November ( vol. 687 , no. 2 ). - P. 1264-1293 . - DOI : 10.1086 / 591785 . - . - arXiv : 0807.1686 .
- ↑ The Extreme Precision Radial Velocity III Conference
- ↑ planetary systems
- Precision super Plan precision // precision precision precision precision Month Month Month Month Month Month Month Month Month Month Month Month Month ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ (↑ ↑ super super super super ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ super ↑ ↑ ↑ )
- ↑ The planet from "Startrek" was not an invention, but the nearest super-earth at the sun-like star.
- ↑ HD 26965b: Super Light Earth in 16 light years
- ↑ Super-Earth Discovered in (Fictional) Vulcan System
- ↑ Geoffrey Mandel, Doug Drexler . Star Trek: Star Charts . - Pocket Books , 2002. - 96 p. - ISBN 0-7434-3770-5 , ISBN 978-0-7434-3770-7 .
- ↑ Sallie Baliunas, Robert Donahue, George Nassiopoulos, Gene Roddenberry . Letter // Sky & Telescope . - Jul 1991 . - p . 5 . (Checked May 4th, 2009)
- ↑ ο² Eridani (English) . Internet Stellar Database . The appeal date is May 4, 2009. Archived February 12, 2012.
Links
- V.V. Ivanov. Astronet> White dwarfs . astronet.ru (September 19, 2002). The appeal date is May 6, 2009. Archived August 22, 2011.
- 40 Eridanus at Solstation (English)