HD 117440
Star in the constellation Centaurus
title: "HD 117440" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["g-type-giants", "binary-stars", "centaurus", "bayer-objects", "durchmusterung-objects", "henry-draper-catalogue-objects", "hipparcos-objects", "bright-star-catalogue-objects"] description: "Star in the constellation Centaurus" topic_path: "science/astronomy" source: "https://en.wikipedia.org/wiki/HD_117440" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Star in the constellation Centaurus ::
| name = d Centauri | image = |image=Centaurus constellation map.svg|alt=|float=center|width=280 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=HD 117440 |x=520|y=380 | caption = Location of d Centauri (circled in red) | epoch = J2000.0 | constell = Centaurus | ra = | dec = | appmag_v = 4.64 + 5.03 | type = | class = G7III + G9III | b-v = +1.17 | u-b = +1.03 | variable = Suspected | radial_v = | prop_mo_ra = | prop_mo_dec = | parallax = 3.60 | p_error = 0.49 | parallax_footnote = | absmag_v = | reference = | period = | axis = | inclination = | node = | periastron = B | eccentricity = | periarg = | source = | mass = | radius = | luminosity = | temperature = 4,683 | gravity = 1.86 | metal_fe = −0.36 | age_myr = | rotational_velocity = 4.5 | names = | Simbad = HD+117440
HD 117440, also known by its Bayer designation d Centauri, is a binary star system in the southern constellation of Centaurus. It is visible to the naked eye with a combined apparent visual magnitude of 3.90. The distance to this system is approximately 900 light years based on parallax measurements. It is drifting closer to the Sun with a radial velocity of −2 km/s.
A companion star was first reported by T. J. J. See in 1897 at an angular separation of from the primary. Orbital elements for the pair were published by W. S. Finsen in 1962 then updated in 1964, yielding an orbital period of 83.1 years with a semimajor axis of and an eccentricity of 0.52. Both components are evolved G-type giant stars with a yellow, Sun-like hue. The primary, component A, has an apparent magnitude of +4.64, while the secondary, component B, has an apparent magnitude of +5.03.
References
References
- {{cite XHIP. 65936
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