LAUSR.org creates dashboard-style pages of related content for over 1.5 million academic articles. Sign Up to like articles & get recommendations!

Ongoing astrometric microlensing events from VVV and Gaia

Photo from academic.microsoft.com

We extend predictive microlensing event searches using the Vista Variables in the Via Lactea survey and the second Gaia data release. We identify two events with maxima in 2019 that… Click to show full abstract

We extend predictive microlensing event searches using the Vista Variables in the Via Lactea survey and the second Gaia data release. We identify two events with maxima in 2019 that require urgent follow-up. First, we predict that the nearby M2 dwarf L 338-152 will align with a background source with a closest approach of $35^{+35}_{-23}$ mas on 2019 November $16^{+28}_{-27}$ d. This will cause a peak astrometric shift and photometric amplification of the background source of $2.7^{+3.5}_{-1.5}$ mas and $5.6^{+143.2}_{-5.2}$ mmag respectively. This event should be astrometrically detectable by both the Hubble Space Telescope (HST) and the Spectro-Polarimetric High-contrast Exoplanet Research instrument on the Very Large Telescope. Secondly, we predict the likely K dwarf NLTT 45128 will lens a background source with a closest approach of $105.3^{+12.2}_{-11.7}$ mas on 2019 September $26^{+15}_{-15}$ d. This will produce a peak astrometric shift of $0.329^{+0.065}_{-0.059}$ mas. NLTT 45128 is only 3.6 magnitudes brighter than the background source which makes it an excellent candidate for follow-up with HST. Characterisation of these signals will allow direct gravitational masses to be inferred for both L 338-152 and NLTT 45128 with an estimated precision of $\sim9$ and $\sim13$ per cent respectively.

Keywords: ongoing astrometric; astrometric microlensing; source; nltt 45128; mas; background source

Journal Title: Monthly Notices of the Royal Astronomical Society: Letters
Year Published: 2019

Link to full text (if available)


Share on Social Media:                               Sign Up to like & get
recommendations!

Related content

More Information              News              Social Media              Video              Recommended



                Click one of the above tabs to view related content.