HD 37756
A blue-white binary in Orion, suspected Beta Cephei variable.
HD 37756 is a binary star system in the equatorial constellation of Orion, positioned less than a degree north of the bright star Alnitak. It has a blue-white hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.95. The system is notable as a double-lined spectroscopic binary with a high orbital eccentricity, and it is a suspected Beta Cephei variable and a candidate eclipsing binary.
- Apparent visual magnitude
- 4.95
- Distance from sun
- approximately 900 light-years
- Radial velocity
- +26 km/s
- Orbital period
- 27.15 days
- Eccentricity
- 0.74
- Stellar classification
- B3V
- Suspected variability period
- 0.37968 days
Lore & Background
The binary nature of HD 37756 was identified by E. B. Frost in 1906. It is a double-lined spectroscopic binary with an orbital period of 27.15 days and a high eccentricity of 0.74. The spectrum matches a massive B-type main-sequence star with a stellar classification of B3V. The secondary is luminous enough to interfere with measurements of the primary spectrum. The system is a member of the OB1b subgroup of the Orion OB1 association and is drifting further away from the Sun with a radial velocity of +26 km/s.
Reader's Guide
HD 37756 is significant as a member of the Orion OB1 association, specifically the OB1b subgroup, which provides context for studying massive star formation and evolution in a nearby star-forming region. Its binary nature, identified over a century ago, offers a case study in spectroscopic binary dynamics with a notably high eccentricity of 0.74. The system is a suspected Beta Cephei variable with a period of 0.37968 days and an amplitude of 0.03 magnitude in the B band, making it a candidate for asteroseismological studies of massive B-type stars. Additionally, it is a candidate eclipsing binary with a minimum dip of 0.04 in visual magnitude during each orbit, which could yield precise stellar parameters if confirmed. The secondary's luminosity interfering with primary spectrum measurements highlights the challenges in disentangling binary star data.
Did You Know?
- The binary nature of this system was identified by E. B. Frost in 1906.
- It has a high orbital eccentricity of 0.74 with a period of 27.15 days.
Frequently Asked Questions
What is HD 37756?
HD 37756 is a blue-white B3V binary star system located in Orion, less than a degree north of Alnitak. It is a double-lined spectroscopic binary with a notably high orbital eccentricity of 0.74 and a period of about 27.15 days.
Where in the sky can I find HD 37756?
Look in the constellation Orion, just under a degree north of the middle belt star Alnitak. At an apparent visual magnitude of 4.95, it is faintly visible to the unaided eye under reasonably dark conditions.
What kind of variable star is HD 37756?
It is classified as a suspected Beta Cephei pulsator and is also a candidate eclipsing binary. Its B3V spectral type and blue-white color place it among the hotter, younger variable-star targets in Orion.
What are HD 37756's key orbital parameters?
The two components complete one full orbit in roughly 27.15 days along a strongly elliptical path (eccentricity 0.74). The system's radial velocity is measured at +26 km/s relative to the Sun.
How far is HD 37756 from Earth?
The system lies approximately 900 light-years away. Despite that distance, its intrinsic luminosity keeps it just within the threshold of naked-eye visibility at magnitude 4.95.
More in Variable Stars, Part 7 1-24
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced