Predicted microlensing events by nearby very-low-mass objects: Pan-STARRS DR1 vs. Gaia DR2

Martin Bo Nielsen, D. M. Bramich

Research output: Contribution to journalArticle

Abstract

Microlensing events can be used to directly measure the masses of single field stars to a precision of ≈ 1−10% . The majority of direct mass measurements for stellar and sub-stellar objects typically only come from observations of binary systems. Hence microlensing provides an important channel for direct mass measurements of single stars. The Gaia satellite has observed ≈ 1.7 billion objects, and analysis of the second data release has recently yielded numerous event predictions for the next few decades. However, the Gaia catalog is incomplete for nearby very-low-mass objects such as brown dwarfs for which mass measurements are most crucial. We employ a catalog of very-low-mass objects from Pan-STARRS data release 1 (PDR1) as potential lens stars, and we use the objects from Gaia data release 2 (GDR2) as potential source stars. We then search for future microlensing events up to the year 2070. The Pan-STARRS1 objects are first cross-matched with GDR2 to remove any that are present in both catalogs. This leaves a sample of 1718 possible lenses. We fit MIST isochrones to the Pan-STARRS1, AllWISE and 2MASS photometry to estimate their masses. We then compute their paths on the sky, along with the paths of the GDR2 source objects, until the year 2070, and search for potential microlensing events. Source-lens pairs that will produce a microlensing signal with an astrometric amplitude of greater than 0.131 mas, or a photometric amplitude of greater than 0.4 mmag, are retained.

Original languageEnglish (US)
Pages (from-to)351-370
Number of pages20
JournalActa Astronomica
Volume68
Issue number4
DOIs
StatePublished - Jan 1 2018

Fingerprint

catalogs
lenses
stars
star distribution
leaves
photometry
sky
estimates
prediction
predictions
analysis

Keywords

  • Astrometry
  • Catalogs
  • Gravitational lensing: micro
  • Methods: data analysis
  • Stars: fundamental parameters

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Predicted microlensing events by nearby very-low-mass objects : Pan-STARRS DR1 vs. Gaia DR2. / Nielsen, Martin Bo; Bramich, D. M.

In: Acta Astronomica, Vol. 68, No. 4, 01.01.2018, p. 351-370.

Research output: Contribution to journalArticle

@article{fd4bc5dd58f0402e906cc542a1c5c623,
title = "Predicted microlensing events by nearby very-low-mass objects: Pan-STARRS DR1 vs. Gaia DR2",
abstract = "Microlensing events can be used to directly measure the masses of single field stars to a precision of ≈ 1−10{\%} . The majority of direct mass measurements for stellar and sub-stellar objects typically only come from observations of binary systems. Hence microlensing provides an important channel for direct mass measurements of single stars. The Gaia satellite has observed ≈ 1.7 billion objects, and analysis of the second data release has recently yielded numerous event predictions for the next few decades. However, the Gaia catalog is incomplete for nearby very-low-mass objects such as brown dwarfs for which mass measurements are most crucial. We employ a catalog of very-low-mass objects from Pan-STARRS data release 1 (PDR1) as potential lens stars, and we use the objects from Gaia data release 2 (GDR2) as potential source stars. We then search for future microlensing events up to the year 2070. The Pan-STARRS1 objects are first cross-matched with GDR2 to remove any that are present in both catalogs. This leaves a sample of 1718 possible lenses. We fit MIST isochrones to the Pan-STARRS1, AllWISE and 2MASS photometry to estimate their masses. We then compute their paths on the sky, along with the paths of the GDR2 source objects, until the year 2070, and search for potential microlensing events. Source-lens pairs that will produce a microlensing signal with an astrometric amplitude of greater than 0.131 mas, or a photometric amplitude of greater than 0.4 mmag, are retained.",
keywords = "Astrometry, Catalogs, Gravitational lensing: micro, Methods: data analysis, Stars: fundamental parameters",
author = "Nielsen, {Martin Bo} and Bramich, {D. M.}",
year = "2018",
month = "1",
day = "1",
doi = "10.32023/0001-5237/68.4.3",
language = "English (US)",
volume = "68",
pages = "351--370",
journal = "Acta Astronomica",
issn = "0001-5237",
publisher = "Copernicus Foundation for Polish Astronomy",
number = "4",

}

TY - JOUR

T1 - Predicted microlensing events by nearby very-low-mass objects

T2 - Pan-STARRS DR1 vs. Gaia DR2

AU - Nielsen, Martin Bo

AU - Bramich, D. M.

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Microlensing events can be used to directly measure the masses of single field stars to a precision of ≈ 1−10% . The majority of direct mass measurements for stellar and sub-stellar objects typically only come from observations of binary systems. Hence microlensing provides an important channel for direct mass measurements of single stars. The Gaia satellite has observed ≈ 1.7 billion objects, and analysis of the second data release has recently yielded numerous event predictions for the next few decades. However, the Gaia catalog is incomplete for nearby very-low-mass objects such as brown dwarfs for which mass measurements are most crucial. We employ a catalog of very-low-mass objects from Pan-STARRS data release 1 (PDR1) as potential lens stars, and we use the objects from Gaia data release 2 (GDR2) as potential source stars. We then search for future microlensing events up to the year 2070. The Pan-STARRS1 objects are first cross-matched with GDR2 to remove any that are present in both catalogs. This leaves a sample of 1718 possible lenses. We fit MIST isochrones to the Pan-STARRS1, AllWISE and 2MASS photometry to estimate their masses. We then compute their paths on the sky, along with the paths of the GDR2 source objects, until the year 2070, and search for potential microlensing events. Source-lens pairs that will produce a microlensing signal with an astrometric amplitude of greater than 0.131 mas, or a photometric amplitude of greater than 0.4 mmag, are retained.

AB - Microlensing events can be used to directly measure the masses of single field stars to a precision of ≈ 1−10% . The majority of direct mass measurements for stellar and sub-stellar objects typically only come from observations of binary systems. Hence microlensing provides an important channel for direct mass measurements of single stars. The Gaia satellite has observed ≈ 1.7 billion objects, and analysis of the second data release has recently yielded numerous event predictions for the next few decades. However, the Gaia catalog is incomplete for nearby very-low-mass objects such as brown dwarfs for which mass measurements are most crucial. We employ a catalog of very-low-mass objects from Pan-STARRS data release 1 (PDR1) as potential lens stars, and we use the objects from Gaia data release 2 (GDR2) as potential source stars. We then search for future microlensing events up to the year 2070. The Pan-STARRS1 objects are first cross-matched with GDR2 to remove any that are present in both catalogs. This leaves a sample of 1718 possible lenses. We fit MIST isochrones to the Pan-STARRS1, AllWISE and 2MASS photometry to estimate their masses. We then compute their paths on the sky, along with the paths of the GDR2 source objects, until the year 2070, and search for potential microlensing events. Source-lens pairs that will produce a microlensing signal with an astrometric amplitude of greater than 0.131 mas, or a photometric amplitude of greater than 0.4 mmag, are retained.

KW - Astrometry

KW - Catalogs

KW - Gravitational lensing: micro

KW - Methods: data analysis

KW - Stars: fundamental parameters

UR - http://www.scopus.com/inward/record.url?scp=85060033846&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85060033846&partnerID=8YFLogxK

U2 - 10.32023/0001-5237/68.4.3

DO - 10.32023/0001-5237/68.4.3

M3 - Article

AN - SCOPUS:85060033846

VL - 68

SP - 351

EP - 370

JO - Acta Astronomica

JF - Acta Astronomica

SN - 0001-5237

IS - 4

ER -