Bibliographic Details
| Title: |
A Candidate High-Velocity Exoplanet System in the Galactic Bulge |
| Authors: |
Terry, Sean K., Beaulieu, Jean-Philippe, Bennett, David P., Bhattacharya, Aparna, Hulberg, Jon, Huston, Macy J., Koshimoto, Naoki, Blackman, Joshua W., Bond, Ian A., Cole, Andrew A., Lu, Jessica R., Ranc, Clément, Rektsini, Natalia E., Vandorou, Aikaterini |
| Source: |
AJ 169, 131 (2025) |
| Publication Year: |
2024 |
| Collection: |
Astrophysics |
| Subject Terms: |
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics |
| More Details: |
We present an analysis of adaptive optics (AO) images from the Keck-I telescope of the microlensing event MOA-2011-BLG-262. The original discovery paper by Bennett et al. 2014 reports two distinct possibilities for the lens system; a nearby gas giant lens with an exomoon companion or a very low mass star with a planetary companion in the galactic bulge. The $\sim$10 year baseline between the microlensing event and the Keck follow-up observations allows us to detect the faint candidate lens host (star) at $K = 22.3$ mag and confirm the distant lens system interpretation. The combination of the host star brightness and light curve parameters yields host star and planet masses of $M_{\rm host} = 0.19 \pm 0.03M_{\odot}$ and $m_p = 28.92 \pm 4.75M_{\oplus}$ at a distance of $D_L = 7.49 \pm 0.91\,$kpc. We perform a multi-epoch cross reference to \textit{Gaia} DR3 and measure a transverse velocity for the candidate lens system of $v_L = 541.31 \pm 65.75$ km s$^{-1}$. We conclude this event consists of the highest velocity exoplanet system detected to date, and also the lowest mass microlensing host star with a confirmed mass measurement. The high-velocity nature of the lens system can be definitively confirmed with an additional epoch of high-resolution imaging at any time now. The methods outlined in this work demonstrate that the \textit{Roman} Galactic Exoplanet Survey (RGES) will be able to securely measure low-mass host stars in the bulge.
Comment: 21 pages, 6 figures, 4 tables, submitted to AJ |
| Document Type: |
Working Paper |
| DOI: |
10.3847/1538-3881/ad9b0f |
| Access URL: |
http://arxiv.org/abs/2410.09147 |
| Accession Number: |
edsarx.2410.09147 |
| Database: |
arXiv |
