242 research outputs found

    Cultivating domesticity : the Homemakers' Clubs of Saskatchewan, 1911-1961.

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    On January 31, 1911, the Homemakers' Clubs of Saskatchewan became an official organisation under the direction of the University of Saskatchewan. Established to provide isolated rural women with companionship, access to education, and the opportunity to carry out community service, Homemakers' Clubs appealed to thousands of farm women because they provided the means by which they could improve themselves, their farm homes, and their communities. Its appeal also lay in the fact that the organisation remained non-political and non-sectarian, focusing instead on women's primary responsibilities to their homes and their families. To that end, Homemakers' Clubs embraced a domestic ideology that institionalised notions of gender and celebrated women's roles in the home. Given that the nature of farm women's work was not restricted to the household, however, Homemakers' Clubs allowed rural women to redefine an urban domesticity to include their farming responsibilities. Moreover, in a setting where gender lines were often blurred and the division of labour was not always strictly defined, membership in an organisation that reinforced gender roles, promoted family and community life, and embraced a traditional mandate provided farm women with a level of respectability and femininity that was often lost in a farming setting. Finally, the domestic ideology under which the Homemakers' Clubs operated allowed its members to find recognition and validation in their work, and, in their goals to elevate home life, to legitimise their work, and to adjust domestic ideology to include their farming responsibilities, the organisation became a space in which its members discussed, debated, explored, and, in some cases, challenged common perceptions of women; they subtly challenged the status quo and demanded validation and recognition for their work in and contributions to their farms and communities. As such, an organisation that may outwardly appear to be a traditional women's organisation devoted strictly to the exchange of recipes and household advice, was, in actuality, quietly political and provided farm women with a sense of identity that enabled them to contribute fundamentally to their rural homes, families, and communities

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

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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

    Dynamics of bacterial blight disease in resistant and susceptible rice varieties

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    Bacterial blight (X. oryzae pv. oryzae) is a serious disease in rice across the world. To better control the disease, it is important to understand its epidemiology and how key aspects of this (e.g. infection efficiency, and spatial spread) change according to environment (e.g. local site conditions and season), management, and in particular, variety resistance. To explore this, we analysed data on the disease progress on resistant and susceptible varieties of rice grown at four sites in the Philippines across five seasons using a combination of mechanistic modelling and statistical analysis. Disease incidence was generally lower in the resistant variety. However, we found no evidence that the primary infection efficiency was lower in resistant varieties, suggesting that differences were largely due to reduced secondary spread. Despite secondary spread being attributed to splash dispersal which is exacerbated by wind and rain, the wetter sites of Pila and Victoria in south Luzon tended to have lower infection rates than the drier sites in central Luzon. Likewise, we found spread in the dry season can be substantial and should therefore not be ignored. In fact, we found site to be a greater determinant of the number of infection attempts suggesting that other environmental and management factors had greater effect on the disease than climate. Primary infection was characterised by spatially-random observations of disease incidence. As the season progressed, we observed an emerging short-range (1.6 m-4 m) spatial structure suggesting secondary spread was predominantly short-range, particularly where the resistant variety was grown

    SN2012ab: A Peculiar Type IIn Supernova with Aspherical Circumstellar Material

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    We present photometry, spectra, and spectropolarimetry of supernova (SN) 2012ab, mostly obtained over the course of 300\sim 300 days after discovery. SN 2012ab was a Type IIn (SN IIn) event discovered near the nucleus of spiral galaxy 2MASXJ12224762+0536247. While its light curve resembles that of SN 1998S, its spectral evolution does not. We see indications of CSM interaction in the strong intermediate-width emission features, the high luminosity (peak at absolute magnitude M=19.5M=-19.5), and the lack of broad absorption features in the spectrum. The Hα\alpha emission undergoes a peculiar transition. At early times it shows a broad blue emission wing out to 14,000-14{,}000 km s1\mathrm{s^{-1}} and a truncated red wing. Then at late times (>> 100\,days) it shows a truncated blue wing and a very broad red emission wing out to roughly +20,000+20{,}000 km s1\mathrm{s^{-1}}. This late-time broad red wing probably arises in the reverse shock. Spectra also show an asymmetric intermediate-width Hα\alpha component with stronger emission on the red side at late times. The evolution of the asymmetric profiles requires a density structure in the distant CSM that is highly aspherical. Our spectropolarimetric data also suggest asphericity with a strong continuum polarization of 13\sim 1-3% and depolarization in the Hα\alpha line, indicating asphericity in the CSM at a level comparable to that in other SNe IIn. We estimate a mass-loss rate of M˙=0.050Myr1\dot{M} = 0.050\, {\rm M}_{\odot}\,\mathrm{yr^{-1}} for vpre=100v_{\rm pre} = 100\,km\,s1\mathrm{s^{-1}} extending back at least 75\,yr prior to the SN. The strong departure from axisymmetry in the CSM of SN 2012ab may suggest that the progenitor was an eccentric binary system undergoing eruptive mass loss.Comment: 18 pages, 12 figure

    SN2013fs and SN2013fr: Exploring the circumstellar-material diversity in Type II supernovae

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    We present photometry and spectroscopy of SN2013fs and SN2013fr in the first 100 days post-explosion. Both objects showed transient, relatively narrow Hα\alpha emission lines characteristic of SNeIIn, but later resembled normal SNeII-P or SNeII-L, indicative of fleeting interaction with circumstellar material (CSM). SN2013fs was discovered within 8hr of explosion. Its light curve exhibits a plateau, with spectra revealing strong CSM interaction at early times. It is a less luminous version of the transitional SNIIn PTF11iqb, further demonstrating a continuum of CSM interaction intensity between SNeII-P and IIn. It requires dense CSM within 6.5×\times1014^{14}~cm of the progenitor, from a phase of advanced pre-SN mass loss shortly before explosion. Spectropolarimetry of SN2013fs shows little continuum polarization, but noticeable line polarization during the plateau phase. SN2013fr morphed from a SNIIn at early times to a SNII-L. After the first epoch its narrow lines probably arose from host-galaxy emission, but the bright, narrow Hα\alpha emission at early times may be intrinsic. As for SN2013fs, this would point to a short-lived phase of strong CSM interaction if proven to be intrinsic, suggesting a continuum between SNeIIn and II-L. It is a low-velocity SNII-L, like SN2009kr but more luminous. SN2013fr also developed an IR excess at later times, due to warm CSM dust that require a more sustained phase of strong pre-SN mass loss.Comment: MNRAS accepted. 28 pages, 23 figures, 8 table

    Recurring outbursts of the supernova impostor AT 2016blu in NGC 4559

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    We present the first photometric analysis of the supernova (SN) impostor AT 2016blu in NGC 4559. This transient was discovered by the Lick Observatory Supernova Search in 2012 and has continued its outbursts since then. Optical and infrared photometry of AT 2016blu reveals at least 19 outbursts in 2012-2022. Similar photometry from 1999-2009 shows no outbursts, indicating that the star was relatively stable in the decade before discovery. Archival {\it Hubble Space Telescope} observations suggest that the progenitor had a minimum initial mass of M>=33M >= 33 M_{\odot} and a luminosity of L>=105.7L >= 10^{5.7} L_{\odot}. AT 2016blu's outbursts show irregular variability with multiple closely spaced peaks having typical amplitudes of 1-2 mag and durations of 1-4 weeks. While individual outbursts have irregular light curves, concentrations of these peaks recur with a period of 113±2\sim 113 \pm 2 d. Based on this period, we predict times for upcoming outbursts in 2023 and 2024. AT 2016blu shares similarities with SN 2000ch in NGC 3432, where outbursts may arise from periastron encounters in an eccentric binary containing a luminous blue variable (LBV). We propose that AT 2016blu's outbursts are also driven by interactions that intensify around periastron in an eccentric system. Intrinsic variability of the LBV-like primary star may cause different intensity and duration of binary interaction at each periastron passage. AT 2016blu also resembles the periastron encounters of η\eta Carinae prior to its Great Eruption and the erratic pre-SN eruptions of SN 2009ip. This similarity and the onset of eruptions in the past decade hint that AT 2016blu may also be headed for a catastrophe, making it a target of great interest.Comment: 18 pages, 14 figures, 6 tables, MNRAS Accepte

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

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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

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

    Full text link
    MCA-1B (also called UIT003) is a luminous hot star in the western outskirts of M33, classified over 20yr 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 AFAnd 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 around 29kK. 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 HD5980 (in the SMC) 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.Comment: accepted in MNRAS. 20 pages, 15 figure
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