LT/SPRAT spectroscopic classification of Gaia microlensing event candidates (part 4)
ATel #14135; Zielinski P., Gromadzki M., Wyrzykowski L., Gezer I., Lam M. C., Ihanec N., Kruszynska K., Rybicki K. A. (Astronomical Observatory, University of Warsaw), Maskoliunas M., Zdanavicius Z., Pakstiene E. (Institute of Theoretical Physics and Astronomy, Vilnius University), Hodgkin S. (Institute of Astronomy, University of Cambridge)
on 31 Oct 2020; 15:13 UT
Credential Certification: Pawel Zielinski (pzielinski.astro@gmail.com)
Subjects: Optical, Microlensing Event, Transient, Variables
We report on spectroscopic observations of next 7 candidates for microlensing events detected primarily by the Gaia Science Alerts programme (http://gsaweb.ast.cam.ac.uk/alerts). Spectra were taken with 2-m Liverpool Telescope (LT, Steele et al. 2004, Proc. SPIE, vol. 5489, 679) equipped with the Spectrograph for the Rapid Acquisition of Transients (SPRAT, Piascik et al. 2014, Proc. SPIE, vol. 9147, id. 91478H) in the optical part of electromagnetic window (400-800 nm) and low-resolution mode (R~350). The observations were gathered between 2020-07-20 and 2020-09-07. The links provided as IAU names of the events lead to the Transient Name Server pages with detailed information.
Gaia Name | IAU Name | RA (J2000) | Dec (J2000) | Discovery date | Discovery G mag | Spectrum date | Class
----------|------------|-------------|--------------|----------------|-----------------|---------------|------------------
Gaia20cvu | AT 2020ndc | 19:26:06.50 | +17:58:47.60 | 2020-06-19 | 13.24 | 2020-07-20 | star/ULENS (1)
Gaia20cvo | AT 2020ncz | 19:32:11.83 | +17:14:05.28 | 2020-06-19 | 15.32 | 2020-07-20 | Be star (2)
Gaia20czv | AT 2020nsh | 20:18:40.13 | +32:07:37.24 | 2020-06-27 | 17.42 | 2020-08-06 | Be star (3)
Gaia20asq | AT 2020cfk | 02:58:53.35 | +65:14:35.20 | 2020-02-08 | 17.08 | 2020-08-06 | T Tauri (4)
Gaia20bzn | AT 2020iik | 19:38:18.21 | +19:32:27.56 | 2020-04-25 | 15.91 | 2020-08-19 | Be star (5)
Gaia20cnv | AT 2020loz | 19:47:32.20 | +23:30:38.88 | 2020-06-01 | 14.23 | 2020-08-19 | star/ULENS (6)
Gaia20dxg | AT 2020ruu | 18:40:49.83 | -10:17:08.27 | 2020-08-21 | 15.55 | 2020-09-07 | star/ULENS (7)
Notes:
(1) broad absorption profiles in Halpha and Hbeta, early (B-A) type continuum, microlensing event candidate.
(2) Halpha in emission, broad absorption feature in Hbeta, reddened Be star.
(3) Halpha in emission, most probably Be star.
(4) emission in Halpha line, Mg triplet and TiO visible, late K-type star, T Tauri star candidate.
(5) early type star continuum, no clear emissions but low SNR, most probably Be star.
(6) absorption lines of Balmer series as well as Mg triplet and TiO bands visible, late-type star, microlensing event candidate.
(7) no clear emission lines but low SNR, microlensing event candidate.
Acknowledgments. We thank LT Support Astronomers for help with observations and data reduction. Observations were carried out under OPTICON programmes XOL20A02 and XOL20B01 (PI: P. Zielinski). This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 730890. We are supported by Polish NCN DAINA grant 2017/27/L/ST9/03221 and Research Council of Lithuania grant No. S-LL-19-2. The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. We acknowledge ESA Gaia, DPAC and the Photometric Science Alerts Team (http://gsaweb.ast.cam.ac.uk/alerts).
