Arto Jarvinen | Searcharxiv

arXiv2026

First results of a continuous monitoring campaign of the PLATO Southern field

The BMK10k project started as an ancillary project to the PLATO ESA mission, dedicated to photometrically monitor the PLATO Southern field, to help with source confusion, and to mitigate the problem of false-positive exoplanet detections. Planned as a long-term project, the BMK10k should see an operational time-scale in the order of a decade, well above the proposed PLATO operational phase. Thus, BMK10k may help resolving single- event transit issues detected with PLATO and may be in the unique situation to transit-detect cold Jupiters in solar-system analogues, which would help in understanding exoplanet orbit alignments.

astro-ph.EP↗

arXiv2003

Spin up in RX J0806+15 - the shortest period binary

RX J0806+15 has recently been identified as the binary system with the shortest known orbital period. We present a series of observations of RX J0806+15 including new optical observations taken one month apart. Using these observations and archival data we find that the period of this system is decreasing over time. Our measurements imply f_dot = 6.11x10^-16 Hz/s, which is in agreement with a rate expected from the gravitational radiation for two white dwarfs orbiting at a given period. However, a smaller value of f_dot = 3.14x10^-16 Hz/s cannot be ruled out. Our result supports the idea that the 321.5 s period is the orbital period and that the system is the shortest period binary known so far and that it is one of the strongest sources of constant gravitational radiation in the sky. Furthermore, the decrease of the period strongly favours the unipolar inductor (or electric star) model rather than the accretion models.

astro-ph↗