R85

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R85
Eso9931d.jpg
The nebula N119; R85 is the brightest of the small triangle of stars in the lower right "arm".
Credit: ESO
Observation data
Epoch J2000       Equinox J2000
Constellation Dorado
Right ascension 05h 17m 56.076s [1]
Declination −69° 16 03.77 [1]
Apparent magnitude  (V)10.84 [2] (10.65 - 10.80 [3] )
Characteristics
Evolutionary stage LBV [4]
Spectral type B5 Iae [3]
Apparent magnitude  (U)10.28 [2]
Apparent magnitude  (B)10.93 [2]
Apparent magnitude  (V)10.84 [2]
Apparent magnitude  (R)10.53 [2]
Apparent magnitude  (I)10.44 [2]
Apparent magnitude  (J)10.103 [1]
Apparent magnitude  (H)9.980 [1]
Apparent magnitude  (K)9.822 [1]
U−B color index −0.65 [2]
B−V color index +0.09 [2]
Variable type LBV [4]
Astrometry
Radial velocity (Rv)292 [5]  km/s
Proper motion (μ)RA: −1.0 [6]   mas/yr
Dec.: −2.3 [6]   mas/yr
Distance 160,000  ly
(50,000 [7]   pc)
Absolute magnitude  (MV)−8.2 −8.5 [3]
Details
1960 (minimum)
Radius 135 [8]   R
Luminosity 350,000 [3]   L
Temperature 13,500 [3]   K
1983 - 1990 (maximum)
Luminosity315,000 [3]   L
Temperature 10,000 [3]   K
Other designations
HD  269321, CPD−69°352, 2MASS  J05175607-6916037, GSC  09162-00359, Sk−69°92
Database references
SIMBAD data

R85 (or RMC 85, after the Radcliffe Observatory Magellanic Clouds catalog [5] ) is a candidate luminous blue variable [9] located in the LH-41 OB association [10] in the Large Magellanic Cloud.

A visual band light curve for R85, plotted from ASAS-SN data R85LightCurve.png
A visual band light curve for R85, plotted from ASAS-SN data

R85 has been shown to vary erratically in brightness with an amplitude of about 0.3 magnitudes. It shows variations on several timescales, sometimes with a distinct 400 day period. It has also shown temperature changes associated with brightness changes over several years, a characteristic of luminous blue variables. [12]

Based on R85's current properties and evolutionary models, it probably started out with an initial mass of 28  M. [10] It is theorized to be making a bubble known as DEM L132a with its stellar wind in the nebula LHA-120 N119, along with S Doradus. [13] It has an infrared excess consistent with a stellar wind contribution. [4]

Related Research Articles

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<span class="mw-page-title-main">Luminous blue variable</span> Type of star that is luminous, blue, and variable in brightenss

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References

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