Lucas, PW;
Smith, LC;
Guo, Z;
Peña, CC;
Minniti, D;
Miller, N;
Alonso-García, J;
... Sanders, JL; + view all
(2024)
The most variable VVV sources: eruptive protostars, dipping giants in the nuclear disc and others.
Monthly Notices of the Royal Astronomical Society
, 528
(2)
pp. 1789-1822.
10.1093/mnras/stad3929.
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Abstract
We have performed a comprehensive search of a VISTA Variables in the Via Lactea (VVV) data base of 9.5 yr light curves for variable sources with ΔKs ≥ 4 mag, aiming to provide a large sample of high amplitude eruptive young stellar objects (YSOs) and detect unusual or new types of infrared variable source. We find 222 variable or transient sources in the Galactic bulge and disc, most of which are new discoveries. The sample mainly comprises novae, YSOs, microlensing events, Long Period Variable stars (LPVs), and a few rare or unclassified sources. Additionally, we report the discovery of a significant population of aperiodic late-type giant stars suffering deep extinction events, strongly clustered in the Nuclear Disc of the Milky Way. We suggest that these are metal-rich stars in which radiatively driven mass loss has been enhanced by super-solar metallicity. Among the YSOs, 32/40 appear to be undergoing episodic accretion. Long-lasting YSO eruptions have a typical rise time of ∼2 yr, somewhat slower than the 6–12 month time-scale seen in the few historical events observed on the rise. The outburst durations are usually at least 5 yr, somewhat longer than many lower amplitude VVV events detected previously. The light curves are diverse in nature, suggesting that multiple types of disc instability may occur. Eight long-duration extinction events are seen wherein the YSO dims for a year or more, attributable to inner disc structure. One binary YSO in NGC 6530 displays periodic extinction events (P=59 d) similar to KH 15D.
| Type: | Article |
|---|---|
| Title: | The most variable VVV sources: eruptive protostars, dipping giants in the nuclear disc and others |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stad3929 |
| Publisher version: | https://doi.org/10.1093/mnras/stad3929 |
| Language: | English |
| Additional information: | Copyright © The Author(s) 2024. Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
| Keywords: | Stars: pre-main sequence, stars: protostars, stars: variables: T Tauri, Herbig Ae/Be, infrared: stars − stars: mass-loss − stars: AGB and post-AGB |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10187580 |
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