The Probable Detection of SN 1923A: The Oldest Radio Supernova?

Based upon the results of VLA observations, we report the detection of two unresolved radio sources that are coincident with the reported optical position of SN 1923A in M83. For the source closest to the SN position, the flux density was determined to be 0.30 +/- 0.05 mJy at 20 cm and 0.093 +/- 0.028 mJy at 6 cm. The flux density of the second nearby source was determined to be 0.29 +/- 0.05 at 20 cm and 0.13 +/- 0.028 at 6 cm. Both sources are non-thermal with spectral indices of alpha = -1.0 +/- 0.30 and -0.69 +/- 0.24, respectively. SN 1923A has been designated as a Type II-P. No Type II-P (other than SN 1987A) has been detected previously in the radio. The radio emission from both sources appears to be fading with time. At an age of approximately 68 years when we observed it, this would be the oldest radio supernova (of known age) yet detected

Near and mid-IR sub-arcsecond structure of the dusty symbiotic star R Aqr

The results of a high-resolution interferometric campaign targeting the symbiotic long-period variable (LPV) R~Aqr are reported. With both near-infrared measurements on baselines out to 10m and mid-infrared data extending to 32m, we have been able to measure the characteristic sizes of regions from the photosphere of the LPV and its extended molecular atmosphere, out to the cooler circumstellar dust shell. The near-infrared data were taken using aperture masking interferometry on the Keck-I telescope and show R~Aqr to be partially resolved for wavelengths out to 2.2 microns but with a marked enlargement, possibly due to molecular opacity, at 3.1 microns. Mid-infrared interferometric measurements were obtained with the U.C. Berkeley Infrared Spatial Interferometer (ISI) operating at 11.15 microns from 1992 to 1999. Although this dataset is somewhat heterogeneous with incomplete coverage of the Fourier plane and sampling of the pulsation cycle, clear changes in the mid-infrared brightness distribution were observed, both as a function of position angle on the sky and as a function of pulsation phase. Spherically symmetric radiative transfer calculations of uniform-outflow dust shell models produce brightness distributions and spectra which partially explain the data, however limitations to this approximation are noted. Evidence for significant deviation from circular symmetry was found in the mid-infrared and more tentatively at 3.08 microns in the near-infrared, however no clear detection of binarity or of non-LPV elements in the symbiotic system is reported.Comment: Accepted to Astrophysical Journal. To appear in volume 534. 14 pages; 3 postscript figure

The psychosocial management of rights restitution: tracing technologies for reparation in post-conflict Colombia

Psychosocial assistance is a crucial aspect of recent state reparation and human rights restitution policies in post-conflict Colombia. Drawing on the methodological tools offered by Science and Technology Studies (STS), we follow the trajectories of a psychosocial protocol for emotional recovery as a technology of reparation deployed in rural communities between 2013 and 2017. We ethnographically describe how psychological and administrative projects are merged in practice and come to shape practices and emotional self-valuations. Building on Serres’ concept of betrayal, we reflect on the potential contours of quantifications embedded in psychosocial assistance as opportunities for different forms of reparation to emerge. These forms of reparation coexist in intertwined epistemic practices of psychosocial assistance. We claim that a potentially alternative form of reparation arises despite the predominance of an administrative design mainly concerned with quantification and efficient policy management

Path of Pluto

This is an illustration of the path of Pluto through the eastern section of the constellation of Gemini