A high-resolution, high S/N, optical HARPS public spectrum of Betelgeuse during minimum
ATel #13525; Luca Sbordone (ESO, Chile), Claudia Paladini (ESO, Chile), Juanita Antilen (Universidad de Chile), Silvina Cardenas (IAFE, Argentina), Giada Casali (INAF-Arcetri, Italy), Avinash Chaturvedi (ESO, Germany), Lorenza Della Bruna (Stockholm University, Sweden), Ana I. Ennis (Instituto de Astrofisica de La Plata, Argentina), Keila Y. Ertini (Instituto de Astrofisica de La Plata, Argentina), Iskra Georgieva (Chalmers University of Technology, Sweden), Aishwarya Girdhar (ESO, Germany), Johanna Hartke (ESO, Chile), Edoardo Iani (ESO, Germany), Heidi Korhonen (ESO, Chile), Francesca Lucertini (Universidad de Andres Bello, Chile), Alonso Luna (Universidad de Andres Bello, Chile), Paula A. Miquelarena Hollger (ICATE, Argentina), Chiara Mazzucchelli (ESO, Chile), Camila Navarrete (ESO, Chile), Raphael A. P. Oliveira (Universidade de Sao Paulo, Brazil), Anna Pala (ESO, Germany), Thallis Pessi (Universidade Federal de Santa Maria, Brazil)), Ana C. Posses (Universidad Diego Portales, Chile), Cinthya Rodriguez (Instituto de Astrofisica de La Plata, Argentina), Linda Schmidtobreick (ESO, Chile), Peter Scicluna (ESO, Chile), Mattia Sirressi (Stockholm University, Sweden), Luis C. Vasconcelos Filho (Valongo Observatory, Brazil), Markus Wittkowski (ESO, Germany), John J. Yana Galarza (Universidade de Sao Paulo, Brazil)
on 26 Feb 2020; 20:48 UT
Credential Certification: Linda Schmidtobreick (lschmidt@eso.org)
On February 12, 2020, approx. 01:32 UT, within the framework of the ESO La Silla Observing School 2020 (https://www.eso.org/sci/meetings/2020/lasilla_school2020.html), four 10s exposure HARPS (HAM mode) spectra of Betelgeuse were obtained, covering the spectral range 378nm to 691nm, at R=115,000 and with a S/N of exceeding 500 per pixel at 640nm after coadding. Betelgeuse is one of brightest stars in the sky, and has been undergoing a dimming event (see https://www.eso.org/public/news/eso2003/). The spectrum is characterised by prominent TiO bands, the main opacity sources in the optical range and one of the candidate's dust precursors. TiO forms when the star cools, and the bands can absorb a large fraction of the visible light. The epoch of our observation falls into the broad minimum of the lightcurve when Betelgeuse reached V=1.614mag (Guinan et al. 2020, ATel #13512). The raw and reduced spectra are public and can be retrieved from the ESO archive (http://archive.eso.org/cms/data-portal.html). They have been obtained under Program/run ID 60.A-9501(C) and OB ID 1000032052. The authors of this communication are the students and tutors of the La Silla Observing School 2020.
