Ross 128: Difference between revisions

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==Radio signals==
==Radio signals==
In the spring of 2017, Arecibo astronomers detected strange radio signals thought to originate from Ross 128 that were unlike any they had seen before.<ref name="TA-20170717"/> [[SETI Institute|SETI]]'s  Allen Telescope Array was used for follow-up observations and was unable to detect the signal but did detect man made interference, making it seem clear that the Arecibo detections were due to transmissions from Earth satellites in geosynchronous orbit. Ross 128 has a declination (a coordinate which can be likened to latitude) of close to 0 degrees, which places it in the thick of a phalanx of these satellites.  Therefore, it can be concluded that the signal was a result of man-made interference.<ref>{{cite web |last1=Shostak |first1=Seth |title=Signals from A Nearby Star System? |url=https://www.seti.org/signals-nearby-star-system |website=seti.org |access-date=17 September 2017}}</ref>
In the spring of 2017, Arecibo astronomers detected strange radio signals thought to originate from Ross 128 that were unlike any they had seen before.<ref name="TA-20170717"/> [[SETI Institute|SETI]]'s  Allen Telescope Array was used for follow-up observations and was unable to detect the signal but did detect man made interference, making it seem clear that the Arecibo detections were due to transmissions from Earth satellites in geosynchronous orbit. Ross 128 has a declination (a coordinate which can be likened to latitude) of close to 0 degrees, which places it in the thick of a phalanx of these satellites.  Therefore, it can be concluded that the signal was most likely a result of man-made interference.<ref>{{cite web |last1=Shostak |first1=Seth |title=Signals from A Nearby Star System? |url=https://www.seti.org/signals-nearby-star-system |website=seti.org |access-date=17 September 2017}}</ref>


==See also==
==See also==

Revision as of 00:33, 25 June 2025

Template:Short description

Ross 128
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Observation data
Epoch J2000      Equinox J2000
Constellation Virgo[1]
Right ascension Template:RA[2]
Declination Template:DEC[2]
Apparent magnitude (V) 11.13[3]
Characteristics
Evolutionary stage Main sequence
Spectral type M4V[4]
U−B Template:Engvar +2.685[5]
B−V Template:Engvar +1.59[6]
Variable type Flare star[7]
Astrometry
Radial velocity (Rv)−31.0[8][9] km/s
Proper motion (μ) RA: Template:Val mas/yr[2]
Dec.: Template:Val mas/yr[2]
Parallax (π)296.3053±0.0302 mas[2]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)13.53[3]
Details
MassTemplate:Val[10] Template:Solar mass
RadiusTemplate:Val[10] Template:Solar radius
Luminosity (bolometric)0.00366 ± 0.00005[10] Template:Solar luminosity
Surface gravity (log g)3.40[11] cgs
TemperatureTemplate:Val[10] K
Metallicity [Fe/H]Template:Val[12] dex
Rotation101–223 days[13]
Rotational velocity (v sin i)Template:Val[14] km/s
Age5.0[15] Gyr
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
Template:Odlist, Vyssotsky 286[16]
Database references
SIMBADdata
Exoplanet Archivedata

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Ross 128 is a red dwarf star in the equatorial zodiac constellation of Virgo, near β Virginis. The apparent magnitude of Ross 128 is 11.13,[3] which is too faint to be seen with the unaided eye. Based upon parallax measurements, the distance of this star from Earth is Template:Convert, making it the twelfth closest stellar system to the Solar System. It was first cataloged in 1926 by American astronomer Frank Elmore Ross.[17]

Properties

File:Near-stars-past-future-en.svg
Distances of the nearest stars from 20,000 years ago until 80,000 years in the future

This low-mass star has a stellar classification of M4 V,[4] which places it among the category of stars known as red dwarfs. It has about 18%[10] of the mass of the Sun and 20%[10] of the Sun's radius, but generates energy so slowly that it has only 0.033% of the Sun's visible luminosity;[3] however, most of the energy being radiated by the star is in the infrared band, with the bolometric luminosity being equal to 0.37% of solar.[10] This energy is being radiated from the star's outer atmosphere at an effective temperature of 3,180 K.[4] This gives it the cool orange-red glow of an M-type star.

Ross 128 is an old disk star, which means it has a low abundance of elements other than hydrogen and helium, what astronomers term the star's metallicity, and it orbits near the plane of the Milky Way galaxy.[18] The star lacks a strong excess of infrared radiation. An infrared excess is usually an indicator of a dust ring in orbit around the star.[19][20]

File:FIVirLightCurve.png
Light curves for a flare on FI Virginis, seen in ultraviolet, blue and visual band light, adapted from Lee and Hoxie (1972),[21]

In 1972, a flare was detected from Ross 128. It was observed to increase in brightness by about half a magnitude in the ultraviolet U band, returning to normal brightness in less than an hour. At optical wavelengths, the brightness changes were almost undetectable.[21] It was classified as a flare star and given the variable star designation FI Virginis.[22] Because of the low rate of flare activity, it is thought to be a magnetically evolved star. That is, there is some evidence that the magnetic braking of the star's stellar wind has lowered the frequency of flares, but not the net yield.[23]

Brightness variations thought to be due to rotation of the star and magnetic cycles similar to the sunspot cycle have also been detected. These cause changes of just a few thousandths of a magnitude. The rotation period is found to be 165.1 days, and the magnetic cycle length 4.1 years.[24]

Ross 128 is orbiting through the galaxy with an eccentricity of 0.122, causing its distance from the Galactic Center to range between Template:Convert.[25] This orbit will bring the star closer to the Solar System in the future. The nearest approach will occur in approximately 71,000 years, when it will come within Template:Convert.[9]

Planetary system

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File:Artist's impression of the planet Ross 128 b.jpg
Artist's impression of the planet Ross 128 b, with the star Ross 128 visible in the background[26]

Ross 128 b was discovered in July 2017 by the HARPS instrument at the La Silla Observatory in Chile, by measuring changes in radial velocity of the host star. Its existence was confirmed on 15 November 2017. It is the second-closest known Earth-size exoplanet, after Proxima b.[27] Ross 128 b has a minimum mass 1.4 times that of Earth; a 2019 study predicts a true mass about 1.8 times Earth and a radius about 1.6 times that of the Earth, with large margins of error.[28] It orbits 20 times closer to its star than Earth orbits the Sun, intercepting only about 1.38 times more solar radiation than Earth,[29][30] increasing the chance of retaining an atmosphere over a geological timescale. Ross 128 b is a closely orbiting planet, with a year (orbital period) lasting about 9.9 days.[31][32] At that close distance from its host star, the planet is most likely tidally locked, meaning that one side of the planet would have eternal daylight and the other would be in darkness.[33][34] Near-infrared high-resolution spectra from APOGEE have demonstrated that Ross 128 has near solar metallicity; Ross 128 b therefore most likely contains rock and iron. Furthermore, recent models generated with these data support the conclusion that Ross 128 b is a "temperate exoplanet in the inner edge of the habitable zone."[35]

Template:OrbitboxPlanet begin Template:OrbitboxPlanet Template:Orbitbox end

A 2024 study of the radial velocity data found an eccentricity of about 0.21 for Ross 128 b, higher than previous estimates and similar to that of Mercury. Given the planet's orbit near the inner edge of the habitable zone, such a high eccentricity would significantly decrease its potential for habitability. This study also searched for additional planets in the system, and did not find any.[13]

Radio signals

In the spring of 2017, Arecibo astronomers detected strange radio signals thought to originate from Ross 128 that were unlike any they had seen before.[36] SETI's Allen Telescope Array was used for follow-up observations and was unable to detect the signal but did detect man made interference, making it seem clear that the Arecibo detections were due to transmissions from Earth satellites in geosynchronous orbit. Ross 128 has a declination (a coordinate which can be likened to latitude) of close to 0 degrees, which places it in the thick of a phalanx of these satellites. Therefore, it can be concluded that the signal was most likely a result of man-made interference.[37]

See also

References

Template:Reflist

External links

Template:Sister project

Template:Sky Template:Nearest systems Template:Virgo

Template:Portal bar

  1. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named constellation
  2. ↑ a b c d Cite error: Invalid <ref> tag; no text was provided for refs named GaiaDR3
  3. ↑ a b c d Cite error: Invalid <ref> tag; no text was provided for refs named RECONS
  4. ↑ a b c Cite error: Invalid <ref> tag; no text was provided for refs named baas36
  5. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named aass26_275
  6. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named warren1978
  7. ↑ Script error: No such module "Citation/CS1".
  8. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named PCRV
  9. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named aaa379
  10. ↑ a b c d e f g Cite error: Invalid <ref> tag; no text was provided for refs named Pineda2021
  11. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named rodono
  12. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named Mannetal2015
  13. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named Liebing2024
  14. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named fouque2018
  15. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named mcintyre2022
  16. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named SIMBAD
  17. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named aj36_856_124
  18. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named sanchez1990
  19. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named apjss154_1_453
  20. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named apj667_1_527
  21. ↑ a b Cite error: Invalid <ref> tag; no text was provided for refs named lee
  22. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named ibvs
  23. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named apj1_309_858
  24. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named sm
  25. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named rmaa34_37
  26. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named eso
  27. ↑ Script error: No such module "citation/CS1".
  28. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named TaskerLaneuville2020
  29. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named 4-planet
  30. ↑ Nearby planet is 'excellent' target in search for life. Paul Rincon, BBC News. 15 November 2017.
  31. ↑ Script error: No such module "Citation/CS1".
  32. ↑ A potentially habitable planet has been discovered just 11 light-years away Template:Webarchive. John Wenz, Astronomy Magazine. 15 November 2017.
  33. ↑ Nearby Earth-sized Alien World Orbits 'Quiet' Star, Boosting Habitable Potential. Ian O'Neill, How Stuff Works. 15 November 2017. Quote: "Tidal lock[ing] is expected for Ross 128 b," says Nicola Astudillo-Defru, who works at the Geneva Observatory, University of Geneva in Switzerland, and is co-author of the study.
  34. ↑ Ross 128. Sol Station. November 2017.
  35. ↑ Script error: No such module "Citation/CS1".
  36. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named TA-20170717
  37. ↑ Script error: No such module "citation/CS1".
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