20 years of photometric microlensing Virtual Observatory Resource

Authors
  1. Mustill A.-J.
  2. Davies M.-B.
  3. Lindegren L.
  4. Published by
    CDS
Abstract

Gaia DR2 offers unparalleled precision on stars' parallaxes and proper motions. This allows the prediction of microlensing events for which the lens stars (and any planets they possess) are nearby and may be well studied and characterised. We identify a number of potential microlensing events that will occur before the year 2035.5, 20 years from the Gaia DR2 reference epoch. We query Gaia DR2 for potential lenses within 100pc, extract parallaxes and proper motions of the lenses and background sources, and identify potential lensing events. We estimate the lens masses from Priam effective temperatures, and use these to calculate peak magnifications and the size of the Einstein radii relative to the lens stars' habitable zones. We identify 7 future events with a probability >10% of an alignment within one Einstein radius. Of particular interest is DR2 5918299904067162240 (WISE J175839.20-583931.6), magnitude G=14.9, which will lens a G=13.9 background star in early 2030, with a median 23% net magnification. Other pairs are typically fainter, hampering characterisation of the lens (if the lens is faint) or the ability to accurately measure the magnification (if the source is much fainter than the lens). Of timely interest is DR2 4116504399886241792 (2MASS J17392440-2327071), which will lens a background star in July 2020, albeit with weak net magnification (0.03%). Median magnifications for the other 5 high-probability events range from 0.3% to 5.3%. The Einstein radii for these lenses are 1-10 times the radius of the habitable zone, allowing these lensing events to pick out cold planets around the ice line, and filling a gap between transit and current microlensing detections of planets around very low-mass stars. We provide a catalogue of the predicted events to aid future characterisation efforts. Current limitations include a lack of many high-proper motion objects in Gaia DR2 and often large uncertainties on the proper motions of the background sources (or only 2-parameter solutions). Both of these deficiencies will be rectified with Gaia DR3 in 2020. Further characterisation of the lenses is also warranted to better constrain their masses and predict the photometric magnifications.

Keywords
  1. Gravitational lensing
  2. Astrometry
  3. Optical astronomy
  4. Trigonometric parallax
  5. Narrow band photometry
  6. Proper motions
Bibliographic source Bibcode
2018A&A...617A.135M
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/617/A135
IVOA Identifier IVOID
ivo://CDS.VizieR/J/A+A/617/A135
Document Object Identifer DOI
doi:10.26093/cds/vizier.36170135

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/617/A135
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/617/A135
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/617/A135
IVOA Table Access TAP
http://tapvizier.cds.unistra.fr/TAPVizieR/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/617/A135/mlens?
https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/617/A135/mlens?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/617/A135/mlens?

History

2018-10-02T08:49:03Z
Resource record created
2018-10-02T08:49:03Z
Created
2018-11-05T10:52:51Z
Updated

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr