2MASS J18082002−5104378

Last updated

[1]

2MASS J18082002−5104378
Observation data
Epoch J2000        Equinox J2000
Constellation Ara [2]
Right ascension 18h 08m 20.02s
Declination −51° 04 37.8
Apparent magnitude  (V)11.9 [3]
Characteristics
Evolutionary stage Subgiant / Red dwarf
Astrometry
Proper motion (μ)RA: −5.672 [4]   mas/yr
Dec.: −12.643 [4]   mas/yr
Parallax (π)1.6775 ± 0.0397  mas [4]
Distance 1,950 [5] [6] [7]   ly
(600  pc)
Details
A
Mass 0.7599 ± 0.0001 [1]   M
Radius 2.44 [4]   R
Luminosity 5.311 [4]   L
Surface gravity (log g)3.0 [3]   cgs
Temperature 5,440 ± 100 [3]   K
Metallicity [Fe/H]-4.1 [3]   dex
Age 13.535±0.002 [1]   Gyr
B
Mass 0.14+0.06
−0.01
[1]   M
Age 13.535±0.002 [1]   Gyr
Other designations
Gaia DR2 6702907209758894848 [5]
Database references
SIMBAD data

2MASS J18082002−5104378 (abbreviated J1808−5104) is an ultra metal-poor (UMP) binary star system, in the constellation Ara, about 1,950 ly (600 pc) [5] [6] [7] from Earth, and is a single-lined spectroscopic binary (SB1). It is one of the oldest stars known, about 13.53 billion years old, possibly one of the first stars, a star made almost entirely of materials released from the Big Bang. A tiny unseen companion, a low-mass UMP star, is particularly unusual.

Contents

System

J1808−5104 is an ultra metal-poor (UMP) star, one that has a logarithmic metallicity [Fe/H] less than −4, or 1/ 10,000 th of the levels in the Sun. [8] It is a single-lined spectroscopic binary, with radial velocity variations in its spectral absorption lines interpreted as orbital motion of the visible star. The companion is invisible, but inferred from the orbit. [1]

J1808−5104 is the brightest UMP star, as a binary system, known, [8] and is part of the "thin disk" of the Milky Way, the part of the galaxy in which the Sun is located, but unusual for such a metal-poor and old star. [9] At 13.53  Gyr , the star is the oldest known thin-disk star, and several billion years older than most estimates for the age of the Milky Way's thin disk. [1]

Primary star

The primary component of the binary star system, 2MASS J18082002−5104378 A, is a subgiant, cooler than the Sun, but larger and more luminous. [3]

Secondary star

The secondary unseen companion, 2MASS J18082002−5104378 B, thought to be a red dwarf, [5] has an orbital period P = 34.757+0.010
−0.010
days and a mass of 0.14  M. [1] It is the first low-mass UMP star to be discovered, and one of the oldest stars in the universe, about 13.53 billion years old. [5] It is possibly one of the first stars, a star made almost entirely of materials released from the Big Bang. [1] [10] [11] [9] [12] [13] [14] [15]

Related Research Articles

<span class="mw-page-title-main">Fornax</span> Constellation in the southern celestial hemisphere

Fornax is a constellation in the southern celestial hemisphere, partly ringed by the celestial river Eridanus. Its name is Latin for furnace. It was named by French astronomer Nicolas Louis de Lacaille in 1756. Fornax is one of the 88 modern constellations.

<span class="mw-page-title-main">HE 0107-5240</span> Extremely metal poor star in the constellation Phoenix

HE0107-5240 is an extremely metal-poor Population II star, located roughly 36000 light-years away from Earth. It is one of the most metal-poor stars known in our Galaxy, with a metallicity [Fe/H] = −5.2±0.2; i.e. it has just 1/160000 of the metal that the Sun has. Because of its very low metallicity, it is believed to be one of the earliest Population II stars to have formed. If so, then it is also very old, with an age of roughly 13 billion years. Because the star is not completely metal-free, it does not belong to the first generation of stars. These stars converted the pristine hydrogen, helium, and lithium formed by the Big Bang into heavier elements, such as carbon, oxygen, and metals.

<span class="mw-page-title-main">Timeline of the early universe</span> Timeline of universe events since the Big Bang 13.8 billion years ago

The timeline of the early universe outlines the formation and subsequent evolution of the Universe from the Big Bang to the present day. An epoch is a moment in time from which nature or situations change to such a degree that it marks the beginning of a new era or age.

<span class="mw-page-title-main">Stellar population</span> Grouping of stars by similar metallicity

In 1944, Walter Baade categorized groups of stars within the Milky Way into stellar populations. In the abstract of the article by Baade, he recognizes that Jan Oort originally conceived this type of classification in 1926.

<span class="mw-page-title-main">Sagittarius Dwarf Spheroidal Galaxy</span> Satellite galaxy of the Milky Way

The Sagittarius Dwarf Spheroidal Galaxy (Sgr dSph), also known as the Sagittarius Dwarf Elliptical Galaxy, is an elliptical loop-shaped satellite galaxy of the Milky Way. It contains four globular clusters in its main body, with the brightest of them—NGC 6715 (M54)—being known well before the discovery of the galaxy itself in 1994. Sgr dSph is roughly 10,000 light-years in diameter, and is currently about 70,000 light-years from Earth, travelling in a polar orbit at a distance of about 50,000 light-years from the core of the Milky Way. In its looping, spiraling path, it has passed through the plane of the Milky Way several times in the past. In 2018 the Gaia project of the European Space Agency showed that Sgr dSph had caused perturbations in a set of stars near the Milky Way's core, causing unexpected rippling movements of the stars triggered when it moved past the Milky Way between 300 and 900 million years ago.

<i>Gaia</i> (spacecraft) European optical space observatory for astrometry

Gaia is a space observatory of the European Space Agency (ESA), launched in 2013 and expected to operate until 2025. The spacecraft is designed for astrometry: measuring the positions, distances and motions of stars with unprecedented precision, and the positions of exoplanets by measuring attributes about the stars they orbit such as their apparent magnitude and color. The mission aims to construct by far the largest and most precise 3D space catalog ever made, totalling approximately 1 billion astronomical objects, mainly stars, but also planets, comets, asteroids and quasars, among others.

<span class="mw-page-title-main">Milky Way</span> Galaxy containing the Solar System

The Milky Way is the galaxy that includes the Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term Milky Way is a translation of the Latin via lactea, from the Greek γαλαξίας κύκλος, meaning "milky circle". From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Doust Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies.

BD+17°3248 is an old Population II star located at a distance of roughly 968 light-years in the Galactic Halo. It belongs to the class of ultra-metal-poor stars, especially the very rare subclass of neutron-capture (r-process) enhanced stars.

<span class="mw-page-title-main">HE 1523-0901</span> Red giant star in the constellation Libra

HE 1523-0901 is the designation given to a red giant star in the Milky Way galaxy approximately 9,900 light years from Earth. It is thought to be a second generation, Population II, or metal-poor, star ([Fe/H] = −2.95). The star was found in the sample of bright metal-poor halo stars from the Hamburg/ESO Survey by Anna Frebel and collaborators. The group's research was published in the May 10, 2007 issue of The Astrophysical Journal.

<span class="mw-page-title-main">Stellar kinematics</span> Study of the movement of stars

In astronomy, stellar kinematics is the observational study or measurement of the kinematics or motions of stars through space.

HD 9578 is a candidate wide binary star system located at a distance of approximately 183 light-years from the Sun in the southern constellation of Sculptor. The main star must be viewed with binoculars or a telescope, as its low apparent visual magnitude of 8.35 is too faint to be viewed with the naked eye. The system is drifting closer to the Sun with a radial velocity of −4 km/s.

Kepler-47 is a binary star system in the constellation Cygnus located about 3,420 light-years away from Earth. The stars have three exoplanets, all of which orbit both stars at the same time, making this a circumbinary system. The first two planets announced are designated Kepler-47b, and Kepler-47c, and the third, later discovery is Kepler-47d. Kepler-47 is the first circumbinary multi-planet system discovered by the Kepler mission. The outermost of the planets is a gas giant orbiting within the habitable zone of the stars. Because most stars are binary, the discovery that multi-planet systems can form in such a system has impacted previous theories of planetary formation.

<span class="mw-page-title-main">HD 140283</span> Star in the constellation Libra

HD 140283 is a metal-poor subgiant star about 200 light years away from the Earth in the constellation Libra, near the boundary with Ophiuchus in the Milky Way Galaxy. Its apparent magnitude is 7.205, so it can be seen with binoculars. It is one of the oldest stars known.

Kepler-444 is a triple star system, estimated to be 11.2 billion years old, approximately 119 light-years (36 pc) away from Earth in the constellation Lyra. On 27 January 2015, the Kepler spacecraft is reported to have confirmed the detection of five sub-Earth-sized rocky exoplanets orbiting the main star. The star is a K-type main sequence star. All of the planets are far too close to their star to harbour life forms.

<span class="mw-page-title-main">Kepler-452</span> G-type main-sequence star in the constellation Cygnus

Kepler-452 is a G-type main-sequence star located about 1,800 light-years away from Earth in the Cygnus constellation. Although similar in temperature to the Sun, it is 20% brighter, 3.7% more massive and 11% larger. Alongside this, the star is approximately six billion years old and possesses a high metallicity. Thus, Kepler-452 can be considered a solar twin, although it could be considered a solar analog due to its age.

Kepler-432 is a binary star system with at least two planets in orbit around the primary companion, located about 2,830 light-years away from Earth.

<span class="mw-page-title-main">Gaia Sausage</span> Remains galaxy merger in the Milky Way

The Gaia Sausage or Gaia Enceladus is the remains of a dwarf galaxy that merged with the Milky Way about 8–11 billion years ago. At least eight globular clusters were added to the Milky Way along with 50 billion solar masses of stars, gas and dark matter. It represents the last major merger of the Milky Way.

HD 128429 is a binary star system located at a distance of 88 light years from the Sun in the southern zodiac constellation of Libra. It has a yellow-white hue and is just barely visible to the naked eye with an apparent visual magnitude of 6.20. The system is drifting closer to the Sun with a radial velocity of −66 km/s and has a high proper motion, traversing the celestial sphere at the rate of 0.945″ per year. It is a well-known high velocity star system with a net heliocentric velocity of 158.8 km/s. The system is orbiting the through the galaxy with a high eccentricity of 0.62, which carries it from as close as 4.1 out to 17.5 kpc away from the Galactic Center.

TOI-561 is an old, metal-poor, Sun-like star, known to have multiple small planets. It is an orange dwarf, estimated to be 10.5 billion years old, and about 79% the mass and 85% the radius of Sol, Earth's sun.

References

  1. 1 2 3 4 5 6 7 8 9 Schlaufman, Kevin C.; Thompson, Ian B.; Casey, Andrew R. (5 November 2018). "An ultra metal-poor star near the hydrogen-burning limit". The Astrophysical Journal . 867 (2): 98. arXiv: 1811.00549 . Bibcode:2018ApJ...867...98S. doi: 10.3847/1538-4357/aadd97 . S2CID   54511945.
  2. "Finding the constellation which contains given sky coordinates". DJM.cc. 2018. Retrieved 5 November 2018.
  3. 1 2 3 4 5 Meléndez, Jorge; Placco, Vinicius M.; Tucci-Maia, Marcelo; Ramírez, Iván; Li, Ting S.; Perez, Gabriel (2016). "2MASS J18082002-5104378: The brightest (V = 11.9) ultra metal-poor star". Astronomy and Astrophysics. 585: L5. arXiv: 1601.03462 . Bibcode:2016A&A...585L...5M. doi:10.1051/0004-6361/201527456. S2CID   119240055.
  4. 1 2 3 4 5 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR.
  5. 1 2 3 4 5 "One of Milky Way's oldest stars discovered". SciNews.com. 6 November 2018. Retrieved 6 November 2018.
  6. 1 2 Crockett, Christopher (12 November 2018). "Puny star might be [a] specimen from [the] early universe". Sky & Telescope . Retrieved 14 November 2018.
  7. 1 2 Williams, Matt (9 November 2018). "Ancient star found that's only slightly younger than the universe itself". Universe Today . Retrieved 14 November 2018.
  8. 1 2 Ezzeddine, Rana; Frevbel, Anna (27 September 2018). "Revisiting the iron abundance in the hyper iron-poor star HE 1327−2326 with UV COS/HST data". The Astrophysical Journal. 863 (2): 168. arXiv: 1807.06153 . Bibcode:2018ApJ...863..168E. doi: 10.3847/1538-4357/aad3cb . S2CID   118918067.
  9. 1 2 Rosen, Jill (5 November 2018). "Johns Hopkins scientist finds elusive star with origins close to Big Bang" (Press release). Johns Hopkins University . Retrieved 5 November 2018. The newly discovered star's composition indicates that, in a cosmic family tree, it could be as little as one generation removed from the Big Bang.
  10. Wehner, Mike (5 November 2018). "Astronomers spot one of the oldest stars ever". BGR . Retrieved 5 November 2018.
  11. "A tiny old star has a huge impact". SpaceRef.com (Press release). Gemini Observatory. 5 November 2018. Retrieved 6 November 2018.[ permanent dead link ]
  12. "Johns Hopkins scientist finds elusive star with origins close to Big Bang" (Press release). Johns Hopkins University. 5 November 2018. Retrieved 5 November 2018 via EurekAlert!.
  13. Starr, Michelle (5 November 2018). "Astronomers have detected one of the oldest stars in the entire universe". ScienceAlert.com. Retrieved 5 November 2018.
  14. Irving, Michael (5 November 2018). "13.5 billion year old star was born just after the Big Bang - and it's in our neighborhood". NewAtlas.com. Retrieved 5 November 2018.
  15. Malewar, Amit (5 November 2018). "Johns Hopkins scientists may have found one of the universe's oldest stars - One of the universe's oldest stars". TechExplorist.com. Retrieved 5 November 2018.