TY - JOUR

T1 - Detection of new eruptions in the Magellanic Clouds luminous blue variables R 40 and R 110

AU - Campagnolo, J. C.N.

AU - Borges Fernandes, M.

AU - Drake, N. A.

AU - Kraus, M.

AU - Guerrero, C. A.

AU - Pereira, C. B.

PY - 2018/5/28

Y1 - 2018/5/28

N2 - We performed a spectroscopic and photometric analysis to study new eruptions in two luminous blue variables (LBVs) in the Magellanic Clouds. We detected a strong new eruption in the LBV R40 that reached V ~ 9.2 in 2016, which is around 1.3 mag brighter than the minimum registered in 1985. During this new eruption, the star changed from an A-Type to a late F-Type spectrum. Based on photometric and spectroscopic empirical calibrations and synthetic spectral modeling, we determine that R 40 reached Teff = 5800-6300 K during this new eruption. This object is thereby probably one of the coolest identified LBVs. We could also identify an enrichment of nitrogen and r-and s-process elements. We detected a weak eruption in the LBV R 110 with a maximum of V ∼ 9.9 mag in 2011, that is, around 1.0 mag brighter than in the quiescent phase. On the other hand, this new eruption is about 0.2 mag fainter than the first eruption detected in 1990, but the temperature did not decrease below 8500 K. Spitzer spectra show indications of cool dust in the circumstellar environment of both stars, but no hot or warm dust was present, except by the probable presence of PAHs in R 110. We also discuss a possible post-red supergiant nature for both stars.

AB - We performed a spectroscopic and photometric analysis to study new eruptions in two luminous blue variables (LBVs) in the Magellanic Clouds. We detected a strong new eruption in the LBV R40 that reached V ~ 9.2 in 2016, which is around 1.3 mag brighter than the minimum registered in 1985. During this new eruption, the star changed from an A-Type to a late F-Type spectrum. Based on photometric and spectroscopic empirical calibrations and synthetic spectral modeling, we determine that R 40 reached Teff = 5800-6300 K during this new eruption. This object is thereby probably one of the coolest identified LBVs. We could also identify an enrichment of nitrogen and r-and s-process elements. We detected a weak eruption in the LBV R 110 with a maximum of V ∼ 9.9 mag in 2011, that is, around 1.0 mag brighter than in the quiescent phase. On the other hand, this new eruption is about 0.2 mag fainter than the first eruption detected in 1990, but the temperature did not decrease below 8500 K. Spitzer spectra show indications of cool dust in the circumstellar environment of both stars, but no hot or warm dust was present, except by the probable presence of PAHs in R 110. We also discuss a possible post-red supergiant nature for both stars.

KW - массивные звезды

KW - переменные звезды

KW - звездный ветер

KW - outflows

KW - Stars: individual: RMC 110

KW - Stars: individual: RMC 40

KW - Stars: massive

KW - Stars: variables: S Doradus

KW - Stars: winds

KW - ESO

KW - MASSIVE STARS

KW - LONG-TERM PHOTOMETRY

KW - stars: variables: S Doradus

KW - stars: winds, outflows

KW - ABUNDANCES

KW - stars: individual: RMC110

KW - S-DORADUS

KW - CATALOG

KW - BRIGHTEST STARS

KW - CHEMICAL-COMPOSITION

KW - YELLOW SUPERGIANTS

KW - POINT-SOURCE

KW - stars: massive

KW - stars: individual: RMC40

UR - http://www.scopus.com/inward/record.url?scp=85047994487&partnerID=8YFLogxK

U2 - 10.1051/0004-6361/201731785

DO - 10.1051/0004-6361/201731785

M3 - Article

AN - SCOPUS:85047994487

VL - 613

JO - ASTRONOMY & ASTROPHYSICS

JF - ASTRONOMY & ASTROPHYSICS

SN - 0004-6361

M1 - 33

ER -