PRECISION: A fast python pipeline for high-contrast imaging -- application to SPHERE observations of the red supergiant VX Sagitariae

P. Scicluna, F. Kemper, R. Siebenmorgen, R. Wesson, Joris Blommaert, S. Wolf

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


The search for extrasolar planets has driven rapid advances in instrumentation, resulting in cameras such as SPHERE at the VLT, GPI at Gemini South and SCExAO at Subaru, capable of achieving very high contrast (∼106) around bright stars with small inner working angles (∼0.1 arcsec). The optimal exploitation of data from these instruments depends on the availability of easy-to-use software to process and analyse their data products. We present a pure-PYTHON pipeline, PRECISION, which provides fast, memory-efficient reduction of data from the SPHERE/IRDIS near-infrared imager, and can be readily extended to other instruments. We apply PRECISION to observations of the extreme red supergiant VX Sgr, the inner outflow of which is revealed to host complex, asymmetric structure in the near- IR. In addition, optical polarimetric imaging reveals clear extended polarized emission on ∼0.5 arcsec scales that varies significantly with azimuth, confirming the asymmetry. While not conclusive, this could suggest that the ejecta are confined to a disc or torus, which we are viewing nearly face on, although other non-spherical or clumpy configurations remain possible. VX Sgr has no known companions, making such a geometry difficult to explain, as there is no obvious source of angular momentum in the system.

Original languageEnglish
Article number471
Pages (from-to)3200-3211
Number of pages12
JournalMonthly Notices of the Royal Astronomical Society
Issue number3
Publication statusPublished - May 2020

Bibliographical note

Funding Information:
We thank the anonymous referee for their careful reading of the manuscript and helpful suggestions that improved the paper. We wish to thank S. Moehler, J. Hron, K. Ohnaka, M. Takami, J. Karr, and G. H.-M. Bertrang for helpful discussions and advice. We would also like to thank the ESO support astronomers for taking the data in service mode and our contact astronomers N. Gibson and M. van den Ancker for their help in preparing the observations and correcting issues. This research has been supported by grants MOST104-2628-M-001-004-MY3 and MOST107-2119-M-001-031-MY3 from the Ministry of Science and Technology and AS-IA-106-M03 from Academia Sinica. This research has made use of the SIMBAD data base, operated at CDS, Strasbourg, France (Wenger et al. 2000). This research has made use of NASA’s Astrophysics Data System.

Publisher Copyright:
© 2020 Oxford University Press. All rights reserved.

Copyright 2022 Elsevier B.V., All rights reserved.


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