J/other/Nat/594.365 Betelgeuse during its Great Dimming (Montarges+, 2021)
A dusty veil shading Betelgeuse during its Great Dimming.
Montarges M., Cannon E., Lagadec E., de Koter A., Kervella P.,
Sanchez-Bermudez J., Paladini C., Cantalloube F., Decin L., Scicluna P.,
Kravchenko K., Dupree A.K., Ridgway S., Wittkowski M., Anugu N., Norris R.,
Rau G., Perrin G., Chiavassa A., Kraus S., Monnier J.D., Millour F.,
Le Bouquin J.B., Haubois X., Lopez B., Stee P., Danchi W.
<Nature, 594, 365-368 (2021)>
=2021Natur.594..365M 2021Natur.594..365M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, supergiant ; Stars, M-type ; Stars, late-type
Keywords: stars individual: Betelgeuse - stars: imaging - supergiants -
stars: mass-loss - infrared: Stars -
techniques: high angular resolution
Abstract:
Red supergiants represent the most common final stage of the evolution
of stars with initial masses between 8 and 30-35 times the mass of the
Sun. During this phase of lifetime ∼10^5 yrs, they experience
substantial mass loss of unknown mechanism (Arroyo-Torres et al.,
2015A&A...575A..50A 2015A&A...575A..50A). This mass loss can affect their evolutionary
path, collapse, future supernova light curve, and ultimate fate as a
neutron star or a black hole.
From November 2019 to March 2020, the second closest red supergiant
(RSG, 222+48-34pc) Betelgeuse experienced a historic dimming of
its visible brightness, witnessed worldwide. Usually between 0.1 and
1.0mag, it went down to 1.614±0.008mag around 7-13 February 2020.
Here we report high angular resolution observations showing that the
southern hemisphere of the star was ten times darker than usual in the
visible. Observations and modeling support the scenario of a dust
clump recently formed in the vicinity of the star due to a local
temperature decrease in a cool patch appearing on the photosphere. The
directly imaged brightness variations of Betelgeuse evolved on a
timescale of weeks. This event suggests that an inhomogeneous
component of red supergiant mass loss is linked to a very contrasted
and rapidly changing photosphere.
Description:
The resolved images were obtained using the spectropolarimetric
high-contrast exoplanet research (SPHERE) instrument, mounted on the
third unit telescope of the European Southern Observatory's
(ESO's) Very Large Telescope (VLT). More precisely, we used one of
its sub-systems, the Zurich imaging polarimeter (ZIMPOL). We observed
Betelgeuse and a point-spread-function calibrator, Rigel, in the
polarimetric P2 mode of ZIMPOL on 31 December 2018, 26 December 2019,
27 January 2020, and 18 and 20 March 2020.
Objects:
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RA (2000) DE Designation(s)
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05 55 10.30 +07 24 25.43 Betelgeuse = alpha Ori
05 14 32.27 -08 12 05.89 Rigel = beta Ori
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 284 44 List of fits images
fits/* . 44 Individual fits images
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 25 F6.4 arcsec/pix scale Scale of the image
27- 28 I2 --- Nx Number of pixels along X-axis
30- 31 I2 --- Ny Number of pixels along Y-axis
33- 55 A23 "datime" Obs.date Observation date
57- 59 I3 Kibyte size Size of FITS file
61-168 A108 --- FileName Name of FITS file, in subdirectory fits
170-284 A115 --- Title Title of the FITS file
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Acknowledgements:
Miguel Montarges, miguel.montarges(at)observatoiredeparis.psl.eu
(End) Patricia Vannier [CDS] 23-Mar-2021