WOH G64 Star - Size, Mass, Diameter, Radius, Facts, Luminosity, Distance to Earth

WOH G64 Star - Size, Mass, Diameter, Radius, Facts, Luminosity, Distance from Earth

WOH G64 Star

In the celestial tapestry of the southern constellation Dorado lies an enigmatic celestial giant – WOH G64 Star. This red supergiant, residing in the Large Magellanic Cloud (LMC), captivates astronomers with its colossal size and luminosity. Join us on a cosmic journey as we unravel the mysteries of WOH G64 Star, exploring its characteristics, location, and the peculiarities that set it apart in the vastness of space.

The Unveiling of WOH G64 Star

Discovered in the 1970s by Bengt Westerlund, Nils Olander, and B. Hedin, WOH G64 earned its name from the initials of its distinguished discoverers. This celestial giant is part of a catalog of supergiant and giant stars in the LMC. Characterized as possibly the largest star known, WOH G64 boasts a radius of 1,788 times that of the Sun and a luminosity around 282,000 times the solar luminosity.

WOH G64 Star

A Stellar Profile

  • Star Type: WOH G64 is classified as a red supergiant with a stellar classification of M5 I, indicating a luminous red supergiant.
  • Size and Distance: With an estimated initial mass of 25 times that of the Sun, WOH G64 spans between 1,540 and 2,575 times the Sun's radius, and it resides at a distance of 160,000 light years from Earth.
  • Variable Nature: WOH G64 exhibits variability, with its visual brightness fluctuating over an 800-day period, possibly making it a carbon-rich Mira variable.

WOH G64 Star Size

The colossal proportions of WOH G64, an OH/IR red supergiant, render it one of the largest stars ever discovered. With a radius estimated between 1,540 and 2,575 times that of the Sun, it challenges the boundaries of stellar dimensions. Its immense size, surpassing even well-known giants like UY Scuti, places WOH G64 at the forefront of our understanding of stellar magnitudes.

WOH G64 Star Mass

The birthright of WOH G64 involves an initial mass of approximately 25 times that of the Sun, setting the stage for a stellar journey destined to culminate in a spectacular supernova event. This substantial mass, coupled with its expansive dimensions, positions WOH G64 among the cosmic heavyweights, offering astronomers valuable insights into the evolutionary pathways of massive stars.

WOH G64 Star Diameter

The expansive reach of WOH G64 extends its influence across the cosmic tapestry, with a diameter ranging from 7.16 to 11.97 astronomical units. This colossal expanse, if placed at the center of our solar system, would engulf the orbit of Jupiter and possibly extend to Saturn. The uncertainty in its diameter adds to the enigma, leaving astronomers eager to unravel the precise dimensions of this celestial giant.

WOH G64 Star Radius

The radiant enormity of WOH G64 unfolds with a radius estimated between 1,540 and 2,575 solar radii. The vast expanse of this red supergiant challenges our perceptions of stellar size, prompting astronomers to delve deeper into the intricacies of its structure. The variability in radius estimates underscores the challenges in deciphering the true extent of this cosmic behemoth.

WOH G64 Star sol

WOH G64 Star Facts

Discovered by Bengt Westerlund, Nils Olander, and B. Hedin in the 1970s, WOH G64 stands as an extraordinary red supergiant in the Large Magellanic Cloud. Its unique spectral features, including OH, H₂O, and SiO maser emissions, set it apart. Surrounded by an optically thick dust envelope and exhibiting peculiar nebular emission lines, WOH G64 continues to captivate astronomers, defying conventional expectations.

  1. Discovery and Naming: WOH G64 was discovered in the 1970s by Bengt Westerlund, Nils Olander, and B. Hedin. The name "WOH" is derived from the initials of the three astronomers and is part of a catalog of giant and supergiant stars in the Large Magellanic Cloud.
  2. Size and Mass: This red supergiant boasts an estimated initial mass of 25 ± 5 times that of the Sun. Its size is extraordinary, with a radius ranging between 1,540 and 2,575 solar radii, potentially making it one of the largest known stars.
  3. Luminosity: WOH G64 shines with a luminosity between 280,000 and 490,000 times that of the Sun. Its brilliance and radiance contribute to its status as one of the most luminous red supergiants.
  4. Temperature and Spectral Type: Classified as an M5 I-type star, WOH G64 exhibits a spectral type between M5 and M7.5e. The star's temperature ranges from 3,008 to 3,400 K, placing it among the coolest red supergiants.
  5. Distance and Location: Positioned in the Large Magellanic Cloud, a satellite galaxy of the Milky Way, WOH G64 resides at a distance of approximately 160,000 light years (50,000 parsecs) from Earth. It is located in the southern constellation of Dorado.
  6. Stellar Environment: Enveloped by a thick dust cloud extending over a light year in diameter, WOH G64's stellar wind has expelled 3 to 9 times the Sun's mass of material, contributing to the formation of this expansive torus.
  7. Variability: WOH G64 is a variable star with fluctuations in visual brightness occurring over an 800-day period. Its variability is characterized by more than a magnitude change, yet the exact type remains uncertain.
  8. Potential Companion: The star is suggested to have a possible companion, speculated to be a late O-type dwarf star. Confirmation of this companion is challenging due to the obscuring effects of intervening dust clouds.
  9. Astrophysical Significance: As one of the largest and most luminous red supergiants, WOH G64 offers astronomers a unique opportunity to study extreme stellar phenomena. Its peculiarities, such as the thick dust envelope and potential binary nature, contribute to our understanding of stellar evolution and interactions.
  10. Contribution to Galactic Understanding: WOH G64, along with other massive stars in the Large Magellanic Cloud, contributes to our understanding of the dynamics, composition, and evolution of galaxies beyond the Milky Way. Its study aids in unraveling the mysteries of the broader cosmic landscape.

WOH G64 Star Luminosity

Radiating with a luminosity ranging from 280,000 to 490,000 times that of the Sun, WOH G64 illuminates the cosmic landscape with its intense brilliance. The interplay between its luminosity, temperature, and mass paints a vivid portrait of a stellar entity on the brink of transformation. WOH G64's luminous output contributes to the ongoing exploration of extreme stellar phenomena.

WOH G64 Star Distance to Earth

Residing at a staggering distance of 160,000 light years in the constellation Dorado, WOH G64 extends its influence far beyond the realms of our Milky Way. Positioned within the Large Magellanic Cloud, this red supergiant remains a celestial marvel that challenges our observational capabilities. Despite uncertainties in its variable type, WOH G64 beckons astronomers to peer deeper into the cosmic abyss, promising further revelations in the dynamic world of stellar astrophysics.

WOH G64 Star sun

WOH G64 Star - Description Table

Property Value
Observation Data
Epoch J2000.0
Equinox J2000.0
Constellation Dorado (LMC)
Right Ascension 04h 55m 10.5252s
Declination -68° 20' 29.998"
Apparent Magnitude (V) 17.7 - 18.8
Evolutionary Stage OH/IR red supergiant
Spectral Type M5 I – M7.5e
Apparent Magnitude (K) 6.849
Apparent Magnitude (R) 15.69
Apparent Magnitude (G) 15.0971
Apparent Magnitude (I) 12.795
Apparent Magnitude (J) 9.252
Apparent Magnitude (H) 7.745
Variable Type Carbon-rich LPV (Mira?)
Radial Velocity (Rv) 294±2 km/s
Proper Motion (μ) RA: 1.108 mas/yr, Dec: −1.348 mas/yr
Parallax (π) −0.2280 ± 0.0625 mas
Distance 160,000 ly (50,000 pc)
Absolute Magnitude (MV) -6.00
Radius 1,788 R☉ (uncertain)
Luminosity 282,000 - 589,000+57,000 L☉ (uncertain)
Surface Gravity (log g) +0.0 to −0.5 cgs
Temperature 3,008 – 3,400 K
Age ≤5 Myr
Constellation Dorado
Right Ascension 04h 55m 10.5252s
Declination −68° 20' 29.998"
Other Designations WOH G64, IRAS 04553-6825, LI-LMC 181, ...


  • The star is surrounded by a torus-shaped dust cloud about a light year in diameter.
  • Variability in visual brightness occurs over an 800-day period.
  • Possible companion: Late O-type dwarf star, not confirmed due to dust obscuration.
  • The star was discovered in the 1970s and is part of a catalog of giant and supergiant stars in the LMC.
  • Estimated distance is 160,000 light years based on its location in the LMC.
  • The star's radius is uncertain, with estimates ranging from 1,540 to 2,575 solar radii.
  • Spectral features include OH, H2O, and SiO masers emission.
  • Unusual spectrum of nebular emission, with hot gas rich in nitrogen and a radial velocity more positive than the star.
  • Possible binary system, but not confirmed due to difficulties in study caused by dust clouds.

Cosmic Dimensions

The colossal size of WOH G64 is a cosmic spectacle. Observations from the Very Large Telescope (VLT) in 2007 provided a bolometric luminosity of 282,000 solar luminosities and an initial mass of about 25 times that of the Sun. However, varying studies yield different values, emphasizing the uncertainties that surround this cosmic behemoth.

WOH G64 Star

Observational Characteristics

Epoch J2000.0, Equinox J2000.0, WOH G64 graces the southern constellation of Dorado within the Large Magellanic Cloud. Its apparent magnitude fluctuates between 17.7 and 18.8, rendering it invisible to the naked eye and amateur telescopes. The enigmatic nature of WOH G64 unfolds in its OH/IR red supergiant evolutionary stage, classified as M5 I – M7.5e.

Astrometry and Distance

Positioned at right ascension 04h 55m 10.5252s and declination −68° 20′ 29.998″, WOH G64 sits at a distance of 160,000 light years (50,000 parsecs) from Earth. Astrometric parameters, including radial velocity (294±2 km/s) and proper motion (RA: 1.108 mas/yr, Dec.: −1.348 mas/yr), solidify its membership in the Large Magellanic Cloud.

Physical Properties

WOH G64's estimated radius spans a monumental 1,788 solar radii, while its temperature dances between 3,008 and 3,400 K. The star defies convention with surface gravity fluctuating between +0.0 and −0.5 cgs. Its age remains a youthful ≤5 million years, promising an enthralling future of astronomical transformations.

Stellar Environment

A thick, expansive dust envelope, encapsulating 3 to 9 solar masses of expelled material, shrouds WOH G64. This cosmic veil, sculpted by the star's robust stellar wind, extends approximately a light year in diameter. The scale of this dusty torus accentuates the star's significance in our cosmic neighborhood.

Variable Star Characteristics

WOH G64 exhibits variability, its visual brightness oscillating by over a magnitude every 800 days. Yet, due to substantial interstellar extinction, the true nature of its variability remains obscured in visual wavelengths. The star's classification as a carbon-rich Mira variable or long-period variable adds an element of mystery to its pulsating behavior.

Potential Companion

A speculative companion, possibly a late O-type dwarf star, has been postulated. However, confirmation remains elusive, obscured by the intricate dance of dust clouds. The potential binary nature of WOH G64 hints at the complexity of stellar interactions in this cosmic theater.

Contribution to Astrophysics

WOH G64, with its unparalleled size, luminosity, and peculiarities, stands as a testament to the extraordinary diversity within our universe. Its study provides crucial insights into the dynamics of red supergiants, their evolution, and the intricate interplay of stellar components. As astronomers continue to unravel the enigma of WOH G64, this celestial giant remains a beacon in the exploration of the cosmic tapestry.

In the Celestial Neighborhood

Situated in the LMC, a satellite galaxy of the Milky Way, WOH G64 stands out as one of the most massive and luminous red supergiants. The LMC, with its intriguing features like the Tarantula Nebula and the Ghost Head Nebula, provides a captivating backdrop for this celestial giant.

Possible Cosmic Partnerships

The mystery deepens as WOH G64 is believed to have a possible companion – a dwarf star of spectral type O. Despite challenges in confirmation due to intervening dust clouds, this hypothetical companion adds another layer to the complexity of WOH G64.

Unraveling Spectral Peculiarities

As telescopes peer into the cosmic expanse, WOH G64's spectral features provide intriguing insights. This red supergiant exhibits a spectrum rich in OH, H₂O, and SiO masers emissions, characteristic of an OH/IR supergiant star. Its stellar atmosphere contributes to a unique spectrum, featuring a strong silicate absorption band in mid-infrared wavelengths, accompanied by line emissions from highly excited carbon monoxide.

Uncertainties and Evolving Understanding

Despite decades of observation, WOH G64 remains shrouded in uncertainties. Varying estimates of its radius, luminosity, and other properties highlight the challenges astronomers face in accurately characterizing such distant and complex celestial objects. The star's initial mass, calculated to be around 25 times that of the Sun, positions it as a prime candidate for a future supernova event.

Artistic Depictions and Scientific Endeavors

Artists' impressions, like those derived from observations made with ESO’s Very Large Telescope Interferometer, bring WOH G64 to life, showcasing the thick, massive torus of matter surrounding the star. Scientific endeavors, including interferometric observations, have enriched our understanding of this celestial giant, revealing details about its optically thick dust envelope and unusual spectral characteristics.

Challenges in Observation

The intrinsic variability of WOH G64 poses challenges for observation. Its visual brightness fluctuations, coupled with significant interstellar extinction, make it a complex subject for study. The uncertainty regarding its variable type adds another layer of complexity to unraveling the star's behavior.

The Celestial Tapestry of Dorado

Positioned within the constellation Dorado, WOH G64 shares its cosmic neighborhood with other intriguing stars and deep sky objects. Dorado, despite being one of the fainter constellations, boasts celestial wonders like the luminous blue variable S Doradus, the red giant Mira variable R Doradus, and the pulsating variable Gamma Doradus.

Continued Exploration and Future Discoveries

As technology advances and observational tools improve, astronomers eagerly anticipate uncovering more secrets hidden within the cosmic depths of WOH G64. Its location in the LMC, combined with its unique characteristics, positions it as a key player in advancing our understanding of stellar evolution, variability, and the dynamic nature of the universe.

Final Thoughts

In the vastness of space, WOH G64 stands as a testament to the cosmic grandeur that continues to captivate and challenge human understanding. As astronomers strive to decode its mysteries, this red supergiant invites us to gaze beyond the familiar and embrace the ever-expanding frontiers of celestial exploration. The enigma of WOH G64 persists, beckoning humanity to unravel the secrets woven into the fabric of the cosmos.

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