Hubbry Logo
MeissaMeissaMain
Open search
Meissa
Community hub
Meissa
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Meissa
Meissa
Meissa
View on Wikipedia
from Wikipedia
Meissa
λ (circled) in the constellation Orion.
Observation data
Epoch J2000      Equinox J2000
Constellation Orion
A
Right ascension 05h 35m 08.27608s[1]
Declination +09° 56′ 02.9913″[1]
Apparent magnitude (V) 3.7[2]
B
Right ascension 05h 35m 08.48130s[3]
Declination +09° 56′ 06.0995″[3]
Apparent magnitude (V) 5.6[2]
Characteristics
A
Spectral type O9 III((f))[4]
U−B color index −1.01[5]
B−V color index −0.21[5]
B
Spectral type B0 V[5]
U−B color index −0.77[5]
B−V color index +0.04[5]
Astrometry
Radial velocity (Rv)+30.10[6] km/s
A
Proper motion (μ) RA: +2.896[1] mas/yr
Dec.: −3.183[1] mas/yr
Parallax (π)2.5936±0.4032 mas[1]
Distanceapprox. 1,300 ly
(approx. 390 pc)
Absolute magnitude (MV)−4.25
B
Proper motion (μ) RA: +2.216[3] mas/yr
Dec.: −1.986[3] mas/yr
Parallax (π)2.4682±0.1543 mas[3]
Distance1,320 ± 80 ly
(410 ± 30 pc)
Absolute magnitude (MV)−1.94
Details
A
Mass34[7] M☉
Radius10.0±0.6[8] R☉
Luminosity200,000+117,000
−74,000[9] L☉
Surface gravity (log g)3.90[10] cgs
Temperature36,000±900[8] K
Metallicity [Fe/H]0.03[10] dex
Age4.2[7] Myr
B
Mass10.3±0.7[11] M☉
Radius4.2±0.8[11] R☉
Luminosity6,300[11] L☉
Surface gravity (log g)4.21±0.10[11] cgs
Temperature25,400±500[11] K
Age1.8[11] Myr
Other designations
λ Orionis, 39 Orionis, 101 G. Orionis, BD+09°879, HIP 26207, SAO 112921
A: HD 36861, HR 1879
B: HD 36862, HR 1880
Database references
SIMBADλ Ori
A
B

Meissa /ˈmaɪsə/, designated Lambda Orionis (λ Orionis, abbreviated Lambda Ori, λ Ori) is a star in the constellation of Orion. It is a multiple star approximately 1,300 ly away with a combined apparent magnitude of 3.33.[12] The main components are an O9 giant star and a B-class main sequence star, separated by about 4″. Despite Meissa being more luminous and only slightly further away than Rigel, it appears 3 magnitudes dimmer at visual wavelengths, with much of its radiation emitted in the ultraviolet due to its high temperature.

Nomenclature

[edit]
Meissa with nebulosity north of φ2 Orionis

Lambda Orionis is the star's Bayer designation. The traditional name Meissa derives from the Arabic Al-Maisan which means 'The Shining One'. Al-Maisan was originally used for Gamma Geminorum, but was mistakenly applied to Lambda Orionis and the name stuck.[13] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[14] to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016[15] included a table of the first two batches of names approved by the WGSN; which included Meissa for this star. It is now so entered in the IAU Catalog of Star Names.[16]

The original Arabic name for this star, Al Hakah (the source for another name for it, Heka) refers to the Arabic lunar mansion that includes this star and the two of Phi Orionis (Al Haḳʽah, 'a White Spot').[13] In Chinese, 觜宿 (Zī Sù), meaning Turtle Beak, refers to an asterism consisting of Meissa and both of Phi Orionis[17] Consequently, the Chinese name for Meissa itself is 觜宿一 (Zī Sù yī, English: the First Star of Turtle Beak.)[18]

Properties

[edit]

Meissa is a giant star with a stellar classification of O9 III and an apparent visible magnitude 3.54. It is an enormous star with about 34[7] times the mass of the Sun and 10 times the Sun's radius. The outer atmosphere has an effective temperature of around 35,000 K,[8] giving it the characteristic blue glow of a hot O-type star.[19] Meissa is a soft X-ray source with a luminosity of 1032 erg s−1 and peak emission in the energy range of 0.2–0.3 keV, which suggests the X-rays are probably being generated by the stellar wind.[20] The stellar wind of Meissa is well characterized by a mass-loss rate of 2.5×10−8 solar masses per year and a terminal velocity of 2,000 km/s.[9]

Meissa is actually a double star with a companion at an angular separation of 4.41 arcseconds along a position angle of 43.12° (as of 1937).[21] This fainter component is of magnitude 5.61 and it has a stellar classification of B0.5 V, making it a B-type main sequence star.[22] There is an outlying component, Meissa C, which is an F-type main sequence star with a classification of F8 V. This star in turn may have a very low mass companion that is probably a brown dwarf.[20]

In 2018, a companion was detected around Meissa A, with a project separation of 10.13 mas. However, it was not detected again.[23]

Ring

[edit]
WISE infrared view of the ring around Meissa, which is the faint "white" star north of the small bright red nebula.
(NASA/JPL-Caltech/UCLA)

Meissa is surrounded by a ring of nebulosity about 12 degrees across. It is thought to be the remains of a supernova explosion, now ionized by the ultraviolet radiation from Meissa itself and some of the surrounding hot stars.[24]

Cluster

[edit]

This star is the dominant member of a 5-million-year-old star-forming region known as the λ Orionis cluster,[25] or Collinder 69. The intense ultraviolet energy being radiated by this star is creating the Sh2-264[26] H II region in the neighboring volume of space, which in turn is surrounded by an expanding ring of cool gas that has an age of about 2–6 million years. The expansion of this gaseous ring may be explained by a former binary companion of Meissa that became a Type II supernova. Such an event would also explain the star's peculiar velocity with respect to the center of the expanding ring, as the explosion and resulting mass loss could have kicked Meissa out of the system. A potential candidate for the supernova remnant is the neutron star Geminga.[27] However, the last is unlikely given the distance between Geminga and the cluster.[28]

[edit]
  • Lambda Orionis A, B and C. Background image was taken with Spitzer and insert showing the AB components is from Gemini
    Lambda Orionis A, B and C. Background image was taken with Spitzer and insert showing the AB components is from Gemini
  • This image taken by the Spitzer Space Telescope shows two low-mass stars in the rectangles that show tails in the 24 Micron filter image. This is seen as signs that Meissa is photoevaporating the disks of these low-mass stars.[19]
    This image taken by the Spitzer Space Telescope shows two low-mass stars in the rectangles that show tails in the 24 Micron filter image. This is seen as signs that Meissa is photoevaporating the disks of these low-mass stars.[29]

References

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Meissa

View on Grokipedia
from Grokipedia
Meissa, designated Lambda Orionis (λ Ori), is a prominent multiple in the constellation Orion, marking the tip of the hunter's upraised club or the crown of his head in . The system lies approximately 1,300 light-years from , with a combined apparent visual magnitude of 3.4, rendering it easily visible to the under . Its primary component is a hot, luminous O8 with supergiant-like luminosity, while the close binary companion is a B0.5 main-sequence star, together forming the brightest members of the young Lambda Orionis , a star-forming region embedded in a vast ring of molecular gas and dust spanning about 150 light-years across a of roughly 200 light-years. The primary star, Lambda Orionis A, has a surface of around 35,000 , a estimated at 25 times that of the Sun, and shines with a of approximately 200,000 solar luminosities. Orbiting it at an angular separation of about 4.4 arcseconds is the secondary, Lambda Orionis B, a hotter but less massive B0.5 V star with a near 27,000 and of roughly 5,500 times the Sun's; the two are gravitationally bound, with the system showing a of +30 km/s relative to the Sun. Fainter companions, including a visual double at magnitudes 5.6 and 9.7, contribute to the system's complexity, observed through telescopes as a striking hierarchical multiple. Astronomically, Meissa anchors the Lambda Orionis ring, a cavity in the possibly sculpted by stellar winds or a past , hosting over 200 young stars and active ; this structure, one of the largest known, is a key site for studying early . The name "Meissa" derives from the "Al-Maisan," originally applied to another star but erroneously transferred here in medieval texts, evoking "the proudly marching one" in reference to Orion's stride; alternative historical designations include "Ras al Jauzah" (Head of the Giant) and the Hindu "Mrigashira" (Deer's Head). With 05h 35m 08s and +09° 56', it exhibits proper motion of -0.34 mas/year in and -2.94 mas/year in , consistent with its membership in the Orion OB1 association.

Nomenclature and Etymology

Historical Names

The star now known as Meissa, or Lambda Orionis, has roots in ancient astronomy, where it was referred to as Al Hak'ah, meaning "the white spot," a designation that captured the faint glow contributed by the star and its nearby companions, φ¹ and φ² Orionis. This name also denoted a lunar in sidereal systems, later anglicized in some Western catalogs as Heka, emphasizing its role as a marker in the sky's divisions. Additionally, the name Meissa itself derives from Al-Maisan, originally applied to γ Geminorum and meaning "the shining one" in , but misattributed to Lambda Orionis by the 14th-century lexicographer Al-Firuzabadi, possibly due to translational errors in star tables. Some interpretations link Al-Maisan to the "proudly marching one," evoking the majestic stride of a in ancient lore, though this connection primarily pertains to the original Geminorum usage. In Indian Vedic astronomy, the star is associated with the Mrigashira nakshatra, the fifth lunar mansion, where it marks the "Deer's Head" (Mriga meaning deer and shira meaning head), positioning it at the forehead of a celestial deer figure spanning Orion's head region. In Greek and Roman traditions, the star formed part of Orion's head, as described by in his 2nd-century , where the cluster including , φ¹, and φ² Orionis was noted as ὁ νεφελοειδής, or "the nebulous one," highlighting its hazy appearance to the . positioned it within the constellation's outline without a specific proper name, treating it as one of the fainter elements in the hunter's figure, a convention that persisted through medieval translations of his work. The adoption of Meissa in Western astronomy accelerated in the , with assigning the Greek letter to it in his 1603 star atlas Uranometria, standardizing its identification as the primary star in Orion's head. Earlier Arabic influences, such as Al-Sufi's 10th-century calling it Al Taḥāyī, and references to it as Rās al-Jauzāʾ (Head of the Central One) by astronomers like and Al-Tizini, gradually integrated into European nomenclature through translations like the 1515 Latin . This evolution culminated in the International Astronomical Union's formal approval of Meissa as the proper name in 2016.

Astronomical Designations

Meissa holds the Lambda Orionis (λ Ori), a system introduced by in 1603 that assigns Greek letters to stars in order of brightness within each constellation. It is also known by the Flamsteed number 39 Orionis, part of the catalog compiled by in the early 18th century, which numbers stars sequentially by in each constellation. The primary component of the system appears in major modern catalogs, including HD 36861 in the Henry Draper Catalogue—a comprehensive 20th-century survey classifying nearly 225,000 stars by spectral type and magnitude. It is listed as HR 1879 in the Harvard Revised Photometry Catalogue, an extension of the HD system providing improved photometric data. Additionally, it is designated HIP 26207 in the Hipparcos Catalogue, derived from the 1997 ESA astrometric mission that measured positions, parallaxes, and proper motions for over 118,000 stars. The (IAU) approved "Meissa" as the proper name for the star on July 20, 2016, through its Working Group on Star Names. In equatorial coordinates for the J2000.0 epoch, Meissa is located at 05h 35m 08.28s and +09° 56′ 03″.

Stellar Characteristics

Physical Properties

Meissa's primary component, Lambda Orionis A, lies at a of approximately 1,300 light-years (400 parsecs) from the Solar System, based on recent analyses of Data Release 3 measurements and other astrometric data (range ~360–400 pc). This places it within the Orion OB1 association, though its exact membership in substructures remains under study due to the star's brightness affecting astrometric precision. The star possesses a mass of about 25 solar masses (M⊙), consistent with its classification as a massive early-type giant and its role in ionizing surrounding nebular material. Its radius is estimated at around 7.7 solar radii (R⊙), yielding a surface area roughly 59 times that of the Sun, which contributes to its high energy output despite the relatively modest expansion compared to more evolved supergiants. Lambda Orionis A radiates with a luminosity of approximately 65,000 solar luminosities (L⊙), predominantly in wavelengths due to its high surface temperature of 35,000 ; this qualifies it as a hot capable of driving significant stellar winds. The absolute visual magnitude stands at approximately -6.9, but bolometric corrections—accounting for non-visible emission—are essential, as they adjust the total energy output by approximately -4.5 magnitudes to reflect the full across all wavelengths.

Spectral Classification

Meissa, the primary component of the Orionis system, is classified as an O8 IIIf , characterized by prominent absorption lines typical of hot, massive stars in this range. This reflects its high surface temperature and class, with the showing strong He I absorption indicative of an atmosphere where is singly ionized. Key diagnostic lines include He I at 4471 and 4541 , whose intensity ratios reveal non-local (non-LTE) effects due to the star's high temperature and low density outer layers. These lines are broadened by the star's rotation, with a projected rotational of v sin i ≈ 45 km/s, which influences the line profiles and provides insights into the star's equatorial . The of Meissa is near-solar, with [Fe/H] ≈ 0, as determined from high-resolution of cluster members, suggesting the formed from gas with standard Galactic abundances. However, there is evidence of enhancement, likely resulting from processing in the , where convective mixing brings nucleosynthesized material to the surface during the post-main-sequence phase. In its evolutionary context, Meissa is in a post-main-sequence stage as a giant, having evolved off the main sequence after core hydrogen exhaustion, with an estimated age of 5–7 million years based on isochrone fitting to the surrounding cluster. The spectrum's effective temperature, derived from these helium lines, aligns with expectations for this evolutionary point.

Multiple Star System

Primary Component

Lambda Orionis A is the primary component of the Meissa multiple star system, classified as an O8 IIIf giant star that dominates the system's luminosity and mass. This massive star is visually paired with the companion Lambda Orionis B, with the pair exhibiting common proper motion consistent with physical association. As an evolved massive star, Lambda Orionis A is expected to undergo significant mass loss through stellar winds, potentially transitioning to a Wolf–Rayet star before ending in a core-collapse supernova explosion. The outer companions in the multiple system are at larger separations, but their physical association with the A-B pair is uncertain.

Companion Stars

The Meissa multiple star system includes several visual companions to the primary O8 IIIf star, observed as a hierarchical multiple, though only the B component is confirmed bound. Orionis B is a B0.5 V main-sequence star at an angular separation of about 4.4 arcseconds (~1480 at the distance of 337 pc) from the primary. Orionis C, D, and others are fainter companions at wider separations (e.g., C at ~29 arcsec, D at ~77 arcsec), with magnitudes around 9–10. Their association with the system is uncertain and likely coincidental, as indicated by Washington Double Star Catalog notes. This arrangement features the close visual binary A-B with more distant probable field stars, promoting observational interest in the system's dynamics.

Associated Structures

Lambda Orionis Ring

The Lambda Orionis Ring is a prominent shell-like structure of neutral hydrogen and molecular gas enveloping the Sh 2-264, which is ionized primarily by the massive O8 giant Meissa (λ Ori). This ring, spanning a physical of approximately 40 pc at the of ~400 pc to the region, exhibits a fragmented morphology with dense globules embedded in more diffuse components. The gas within the ring reaches typical volume densities of around 10310^3 cm−3^{-3} in the molecular clumps, contributing to its role as a site of ongoing dynamical processes. The formation of the ring is driven by stellar feedback from Meissa and the surrounding OB association, where powerful stellar winds and intense ultraviolet radiation have carved out a central bubble, expelling and compressing the ambient into an expanding shell. This feedback mechanism has sculpted the ring over roughly 5 million years, aligning with the age of the associated . While some evidence points to an additional influence from a approximately 1 Myr ago that may have enhanced the expansion, the primary driver remains the radiative and mechanical output from the central stars. Key observations of the ring include 21 cm HI emission surveys, which reveal a prominent central cavity devoid of neutral hydrogen, consistent with the ionized interior of Sh 2-264. CO (J=1–0) line mapping has outlined the molecular distribution, highlighting the ring's toroidal shape, clumpy substructures, and velocity gradients indicative of expansion. These CO data indicate a total molecular gas mass of about 1.4×1041.4 \times 10^4 M⊙_\odot, while infrared observations trace the coextensive content, suggesting a dust-to-gas ratio typical of the . High-resolution studies, including recent millimeter-wave imaging, have further resolved arc-like features in the gas distribution, underscoring the ring's dynamic evolution.

Lambda Orionis Cluster

The Lambda Orionis Cluster, also known as Collinder 69, is a young centered on the multiple Meissa (λ¹ Orionis) and containing approximately 200 candidate members spanning a mass range from low-mass stars to the most massive member, Meissa itself. The cluster lies at a distance of about 400 pc, consistent with parallax measurements for its central stars. This structure forms part of the broader Lambda Orionis star-forming region and shares a common distance with the surrounding interstellar ring. Membership in the cluster has been established through a combination of photometric, astrometric, and spectroscopic studies, with around 33 stars spectroscopically confirmed as members based on youth indicators such as absorption and radial velocities. Among these, several OB-type stars have been identified, contributing to the cluster's high-mass , though the exact number of confirmed OB members is limited to a core group including Meissa (O8 III) and about a dozen B-type companions. The cluster exhibits a low velocity dispersion of approximately 2.3 km/s in radial velocities, suggesting it remains dynamically bound despite its youth. Astrometric data from indicate a mean for cluster members of μ_α cos δ ≈ +2.9 mas/yr and μ_δ ≈ -3.2 mas/yr, centered on Meissa's values. The cluster's age is estimated at 5 million years, based on isochrone fitting to its Hertzsprung-Russell diagram and the evolutionary stage of its pre-main-sequence members, with Meissa representing the most massive and earliest-formed star at around 24 M_⊙. This young age is evidenced by the presence of classical stars showing accretion signatures, indicating ongoing low-mass . The in the cluster appears to have been triggered by compression of molecular clouds associated with the expanding ring structure, leading to a burst of activity that produced both high- and low-mass stars in a relatively short episode. The of Collinder 69 shows a turnover at around 0.7 M_⊙, with a flatter for substellar masses, highlighting efficient formation of alongside stars.

Observation and Significance

Visibility and Location

Meissa occupies a prominent position in the constellation Orion, marking the head of the celestial hunter and situated between the shoulders delineated by to the west and to the east. The star system's combined of +3.39 renders it readily visible to the unaided eye from locations with minimal and clear skies. Optimal viewing conditions in the occur during winter evenings from through , when Orion is well-placed high in the southern sky, culminating near midnight in mid-January. For precise location, Meissa's equatorial coordinates (J2000.0) are 05ʰ 35ᵐ 08ˢ and +09° 56' 03", positioning it about 10° north of stars, which aids in using finder charts for identification. While the primary component appears as a single point in , resolving the multiple —particularly the B companion separated by 4.4 arcseconds from the primary—demands a of at least 100 mm under good seeing conditions.

Scientific Importance

Meissa, also known as Lambda Orionis, was first documented in ancient astronomical catalogs, including Ptolemy's from the 2nd century AD, where it appears as a prominent in the constellation Orion. The star's nature as a multiple system was resolved in the through visual observations by Friedrich Georg Wilhelm von Struve, who identified the components in the early 1830s. Key observational studies in the 1980s utilized the International Ultraviolet Explorer (IUE) to obtain high-resolution UV spectra of Meissa, revealing strong P Cygni profiles in lines such as C IV and Si IV that indicate powerful stellar winds with terminal velocities exceeding 2,000 km/s. These observations provided early insights into the wind structure of early-type O stars, with Meissa's mass-loss rate estimated at approximately 2.5 × 10^{-8} M_⊙ yr^{-1}. In the 2010s, data from the mission significantly refined the distance to the system, placing it at about 378–392 pc based on DR2 and DR3 parallaxes (as of Gaia DR3 in 2022). As an O8 IIIf giant in a multiple system, Meissa serves as an for studying winds in OB stars, where its UV and emissions test theoretical models of radiatively driven outflows and their role in mass loss during massive star evolution. Observations have highlighted how these winds contribute to feedback in star-forming environments, influencing the dynamics of the Lambda Orionis cluster and ring nebula, and providing benchmarks for evolutionary tracks that predict progression toward Wolf-Rayet phases or supernovae. Recent developments since 2020 include high-resolution mapping of the surrounding dust ring, with studies confirming the role of stellar feedback in shaping its structure through hydrodynamic simulations and polarimetric data, aligning with models of photoevaporation and wind interactions; for instance, 2024 optical polarimetry has mapped the plane-of-the-sky magnetic field geometry in the region. Future research prospects focus on long-term monitoring of Meissa's variability, including potential orbital changes in its binary components that could reveal mass transfer or evolutionary shifts, using facilities like Gaia and upcoming JWST follow-ups on the region's interstellar medium.

References

  1. http://stars.astro.illinois.edu/sow/meissa.html
  2. http://simbad.cds.unistra.fr/simbad/sim-basic?Ident=Lambda+Ori
  3. https://ui.adsabs.harvard.edu/abs/2021csss.confE.269C/abstract
  4. https://ui.adsabs.harvard.edu/abs/1989A&A...218..231Z
  5. https://www.constellationsofwords.com/meissa/
  6. https://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Orion*.html
  7. https://nineplanets.org/meissa/
  8. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+36861
  9. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HR+1879
  10. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HIP+26207
  11. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Lambda+Orionis
  12. https://www.aanda.org/articles/aa/full_html/2024/09/aa49720-24/aa49720-24.html
  13. https://academic.oup.com/mnras/article/534/3/2566/7760396
  14. https://arxiv.org/abs/astro-ph/0409499
  15. https://www.aanda.org/articles/aa/pdf/2011/06/aa16621-11.pdf
  16. https://academic.oup.com/mnras/article/524/4/6285/7226712
  17. https://academic.oup.com/mnras/article/505/4/4874/6289925
  18. https://vizier.cds.unistra.fr/viz-bin/VizieR-S?WDS%20J05351%2b0956AB
  19. https://arxiv.org/pdf/astro-ph/0110160
  20. https://www.researchgate.net/publication/234249478_The_lambda_-Orionis_Ring_in_CO
  21. https://arxiv.org/abs/2406.02193
  22. https://iopscience.iop.org/article/10.1086/319946/fulltext/
  23. https://arxiv.org/abs/astro-ph/0411438
  24. https://www.constellation-guide.com/constellation-list/orion-constellation/
  25. https://www.universeguide.com/star/26207/meissa
  26. https://simbad.u-strasbg.fr/simbad/sim-id?Ident=Lambda+Orionis
  27. https://theskylive.com/sky/stars/meissa-lambda-orionis-star
Add your contribution
Related Hubs
User Avatar
No comments yet.