VLT/X-Shooter spectroscopic classification of candidates for microlensing events
ATel #11634; K. Kruszynska, M. Gromadzki, L. Wyrzykowski, P. Zielinski, M. Zielinski, K. Rybicki, P. Mroz (Warsaw University Astronomical Observatory), A. Hamanowicz (ESO), S. T.Hodgkin (IoA Cambridge)
on 11 May 2018; 09:42 UT
Credential Certification: Lukasz Wyrzykowski (wyrzykow@astrouw.edu.pl)
Subjects: Optical, Microlensing Event
We report on systematic spectroscopic observations of candidates for microlensing events detected primarily by Gaia Science Alerts programme, located in the Galactic Disk and the Bulge. We observed 13 events discovered by Gaia (with one found also by OGLE and MOA), 3 from OGLE (http://ogle.astrouw.edu.pl/ogle4/ews/ews.html, Udalski et al. 2015) and one from ASAS-SN (http://www.astronomy.ohio-state.edu/~assassin/transients.html, Shappee et al. 2014). Spectra were taken with ESO/VLT/X-Shooter instrument with slit widths 1.0'', 0.7'', 0.6'' yielding resolutions of ~6000, ~10500, ~8000 in UBV, VIS and NIR, respectively.
Survey Name | IAU Name | RA (J2000) | Dec (J2000) | Discovery date | Discovery mag | Observation date | Class | Notes
--------------|-------------|-------------|--------------|----------------|-----------------|------------------|-----------| ------
Gaia17clq | AT2017hag | 18:27:30.78 | -38:27:09.68 | 2017-09-23.56 | 16.45 (G) | 2017-10-16 |star/ULENS |
Gaia17ctl | AT2017hvl | 18:05:36.05 | -33:36:34.99 | 2017-01-11.27 | 14.40 (G) | 2017-11-06 |star/ULENS |
Gaia18aen | AT2018id | 08:02:52.07 | -30:18:37.15 | 2018-01-17.18 | 11.33 (G) | 2018-03-22 |nova? | WRAY15-136 (1)
Gaia18aju | AT2018tx | 17:55:41.45 | -29:13:12.47 | 2018-02-08.18 | 16.89 (G) | 2018-03-04 |star/ULENS |
Gaia18ajt | AT2018tw | 17:48:31.98 | -35:05:16.87 | 2018-02-08.36 | 15.59 (G) | 2018-03-05 |star/ULENS | OGLE-2018-BLG-0229/MOA-2018-BLG-003
Gaia18ajz | AT2018uh | 18:30:14.46 | -08:13:12.76 | 2018-02-09.59 | 17.91 (G) | 2018-03-25 |star/ULENS |
Gaia18akn | AT2018ux | 18:25:00.72 | -15:48:54.04 | 2018-02-09.67 | 12.99 (G) | 2018-03-08 |Be star |
Gaia18akt | AT2018vd | 06:25:18.09 | +12:32:10.54 | 2018-02-09.23 | 13.56 (G) | 2018-03-08 |Be star |
Gaia18alf | AT2018vm | 18:35:45.66 | -13:52:21.00 | 2018-02-11.92 | 17.09 (G) | 2018-03-23 |star/ULENS |
Gaia18asq | AT2018amz | 08:14:31.21 | -25:13:01.49 | 2018-03-25.67 | 15.12 (G) | 2018-03-28 |T Tauri/YSO| (2)
Gaia18atq | AT2018aoh | 17:21:06.27 | -37:10:12.36 | 2018-03-29.35 | 16.14 (G) | 2018-04-20 |Be star |
Gaia18auy | AT2018apy | 15:18:00.68 | -57:43:22.40 | 2018-04-01.12 | 15.34 (G) | 2018-04-20 |Be star |
Gaia18awn | AT2018asm | 11:03:52.22 | -53:57:00.72 | 2018-04-06.72 | 16.09 (G) | 2018-04-12 |BL Lac | featureless spectrum
Survey Name | IAU Name | RA (J2000) | Dec (J2000) | Observation date | Class | Notes
-------------------|-------------|-------------|--------------|------------------|-----------|----------
OGLE-2016-BLG-0341 | --- | 17:50:10.04 | -33:54:51.2 | 2018-03-11 | star | unusual light curve
OGLE-2017-BLG-0074 | --- | 17:35:14.30 | -27:37:20.8 | 2018-03-08 | star/ULENS|
OGLE-2017-BLG-0958 | --- | 17:58:13.64 | -31:38:32.5 | 2018-03-11 | star/ULENS|
ASASSN-18fb | --- | 11:12:05.36 | -68:11:42.4 | 2018-03-13 | star/ULENS|
(1) Spectrum of Gaia18aen shows an M-star continuum superimposed with strong emission lines of H, HeI, HeII, OI, [O III] similar to nova emission spectrum in nebular post-outburst phase. ASAS-SN Sky Patrol light curve shows 3mag nova-like outburst lasting around 100 days.
(2) Spectrum of Gaia18asq shows late type continuum with Halpha in emission and Li I 6708A in absorption.
We acknowledge ESA Gaia, DPAC and the Photometric Science Alerts Team (http://gsaweb.ast.cam.ac.uk/alerts). We thank ESO/VLT staff for support. Observations were carried out under ESO programmes 0100.D-0021(A) and 0101.D.0035(A), PI: Wyrzykowski.
