International Courts and Tribunals

Caplan, Lee M.; Combs, Nancy Amoury; Nesser, Carl Magnus; Onwuamaegbu, Ucheora O.; Romano, C.

doi:10.1017/cbo9780511642395.016

Cited by 8 publications

(9 citation statements)

References 8 publications

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“…Romano's star (Romano 1978), also called GR 290 or v532, is a luminous and peculiar LBV that is sometimes referred to as an LBV candidate because it does not quite fit expectations for typical LBVs -namely, it stays hot and shows little or no colour variation during eruptions, like MCA-1B. This LBV has been studied in detail; see the recent overview by Maryeva et al (2019) and several other studies (Romano 1978;Polcaro et al 2003Polcaro et al , 2016Kurtev et al 2001;Fabrika et al 2005;Viotti et al 2006Viotti et al , 2007.…”

Section: Romano's Star (Gr 290) In M33mentioning

confidence: 99%

A new and unusual LBV-like outburst from a Wolf–Rayet star in the outskirts of M33

Smith

Andrews

Moe

et al. 2020

Monthly Notices of the Royal Astronomical Society

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MCA-1B (also called UIT003) is a luminous hot star in the western outskirts of M33, classified over 20 yr ago with a spectral type of Ofpe/WN9 and identified then as a candidate luminous blue variable (LBV). Palomar Transient Factory data reveal that this star brightened in 2010, with a light curve resembling that of the classic LBV star AF And in M31. Other Ofpe/WN9 stars have erupted as LBVs, but MCA-1B was unusual because it remained hot. It showed a WN-type spectrum throughout its eruption, whereas LBVs usually get much cooler. MCA-1B showed an almost four-fold increase in bolometric luminosity and a doubling of its radius, but its temperature stayed 29 kK. As it faded, it shifted to even hotter temperatures, exhibiting a WN7/WN8-type spectrum, and doubling its wind speed. MCA-1B is reminiscent of some supernova impostors, and its location resembles the isolated environment of SN 2009ip. It is most similar to HD 5980 (in the Small Magellanic Cloud) and GR 290 (also in M33). Whereas these two LBVs exhibited B-type spectra in eruption, MCA-1B is the first clear case where a Wolf-Rayet (WR) spectrum persisted at all times. Together, MCA-1B, HD 5980, and GR 290 constitute a class of WN-type LBVs, distinct from S Doradus LBVs. They are most interesting in the context of LBVs at low metallicity, a possible post-LBV/WR transition in binaries, and as likely Type Ibn supernova progenitors.

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Section: Romano's Star (Gr 290) In M33mentioning

confidence: 99%

A new and unusual LBV-like outburst from a Wolf–Rayet star in the outskirts of M33

Smith

Andrews

Moe

et al. 2020

Monthly Notices of the Royal Astronomical Society

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“…Few studies have been performed of H ii regions surrounding individual stars in M 33, and fewer still of the ISM environment of an LBVs in this galaxy. Thus, the study of GR 290 (M 33 V0532 or Romano's star), classified as an LBV candidate (Romano 1978;Humphreys & Davidson 1994), but suspected of being a post-LBV star transitioning into the WR phase (Polcaro et al 2016), is extremely relevant. Its long term photometric behavior includes a rise to maximum brightness (B ∼16.1 mag) in the 1990's and a slow decline interrupted by brief brightness enhancements (Polcaro et al 2016).…”

Section: Introductionmentioning

confidence: 99%

Wind and nebula of the M 33 variable GR 290 (WR/LBV)

Maryeva

Koenigsberger

Egorov

et al. 2018

A&A

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Context: GR 290 (M 33 V0532=Romano's star) is a luminous M 33 object undergoing photometric variability typical for luminous blue variable (LBV) stars. It lies inside Wolf-Rayet region in the Hertzsprung-Russell diagram and possesses a WN8 type spectrum at the light minima. Analysis of Gran Telescopio Canarias (GTC) spectra obtained in 2016 led to the conclusion that it is surrounded by an unresolved H ii region formed mostly of ejected material from the central star, and disclosed the presence of a second, more extended asymmetrical emission region. Aims: The aim of this paper is to further explore the structure of the nearby environment of GR 290. Methods: Long-slit spectra of GR 290 were obtained with three slit orientations in the visual and red spectral regions. The emissionline distribution for each slit was analyzed. Results: We confirm the presence of an asymmetric H ii region that extends ∼50 pc to the south; ∼30 pc to the north and southeast; ∼20 pc to the east and northwest and ∼10 pc to the west. We also present the first spectrum to be acquired of a star belonging to the neighboring OB 88 association, J013501.87+304157.3, which we classify as a B-type supergiant with a possible binary companion.

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“…Romano's star is located in the outer spiral arm of the M33 galaxy at a distance of about 17 arcmin from the centre. The first light curve for V532 was presented by Romano (1978), while the first spectral observations were obtained in 1992 (Szeifert 1996). Because V532 demonstrates pronounced photometrical and spectral variability (Kurtev et al 2001;Polcaro, Gualandi & Norci 2003), it is classified as an LBV.…”

mentioning

confidence: 99%

Modelling the optical spectrum of Romano’s star★

Maryeva

Abolmasov

2011

Monthly Notices of the Royal Astronomical Society

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We consider the luminous blue variable (LBV) star V532 in M33, also known as Romano’s star, in two different spectral states: in the optical minimum of 2007/2008 and during a local brightening in 2005. Optical spectra of low and moderate resolution are modelled using the non‐local thermodynamic equilibrium model atmosphere code cmfgen. All the observed properties of the object in the minimum are well described by a late WN (nitrogen‐sequence Wolf‐Rayet) star model with a relatively high hydrogen abundance (H/He = 1.9), while the spectrum during the outburst corresponds to the spectral class WN11 and is similar to the spectrum of P Cyg. The atmosphere is enriched in nitrogen by about a factor of 6 in both states. Most of the heavy‐element abundances are consistent with the chemical composition of M33. Bolometric luminosity is shown to vary between the two states by a factor of ∼1.5. This makes V532 another example of an LBV that shows variations in its bolometric luminosity during an outburst.

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International Courts and Tribunals

Abstract: This article summarizes significant developments in 2006 concerning international courts and tribunals, particularly events relating to the

Cited by 8 publications

References 8 publications

A new and unusual LBV-like outburst from a Wolf–Rayet star in the outskirts of M33

A new and unusual LBV-like outburst from a Wolf–Rayet star in the outskirts of M33

Wind and nebula of the M 33 variable GR 290 (WR/LBV)

Modelling the optical spectrum of Romano’s star★

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