Informace o publikaci

Unraveling the brown dwarf desert: Four new discoveries and a unifying period-coded picture

Autoři	SUBJAK Jan BRAHM Rafael LIPTAK Jozef EBERHARDT Jan TALA PINTO Marcelo CASEWELL Sarah L. HENNING Thomas HESSE Katharine TRIFONOV Trifon JORDAN Andres ROJAS Felipe I. VÍTKOVÁ Michaela SALINAS Helem BOYLE Gavin SUC Vincent ANTONUCCI Luca BERNACKI Krzysztof BRICENO Cesar COLLINS Karen A. FERNANDEZ FERNANDEZ Jorge GILL Samuel JANÍK Jan LAW Nicholas MANN Andrew W. MCCORMAC James POPOWICZ Adam SEBASTIAN Daniel SKARKA Marek VACLAVIK Jan VANZI Leonardo WEST Richard G. WILKIN Francis P. ZIEGLER Carl
Rok publikování	2026
Druh	Recenzovaný odborný článek
Časopis / Zdroj	ASTRONOMY & ASTROPHYSICS
Fakulta / Pracoviště MU	Přírodovědecká fakulta
Citace
www	https://www.aanda.org/articles/aa/pdf/2026/05/aa58244-25.pdf
Doi	https://doi.org/10.1051/0004-6361/202558244
Klíčová slova	techniques: photometric; techniques: radial velocities; techniques: spectroscopic; planets and satellites: formation; planet-disk interactions; brown dwarfs
Přiložené soubory	2576818.pdf
Popis	We present four newly validated transiting brown dwarfs identified through TESS photometry and confirmed with high-precision radial velocity measurements obtained from the FEROS and PLATOSpec spectrographs. Notably, three of these companions exhibit orbital periods exceeding 100 days, thereby expanding the sample of long-period transiting brown dwarfs from four to seven systems. The host stars of the long-period brown dwarfs show mild subsolar metallicity. These discoveries highlight the expansion of the metal-poor long-period distribution and help us better understand the brown dwarf desert. In our comparative analysis of eccentricity and metallicity demographics, we utilized catalogs of long-period giant planets, brown dwarfs, and low-mass stellar companions. After accounting for tidal influences, the eccentricity distribution aligns with that of low-mass stellar binaries, presenting a different profile than that observed within the giant planet population. Additionally, the metallicity of the host stars reveals a noteworthy trend: Short-period transiting brown dwarfs are predominantly associated with metal-rich stars, whereas long-period brown dwarfs are more often found around metal-poor stars, thus demonstrating statistical similarities to low-mass stellar hosts. This trend has been previously observed in studies of hot and cold Jupiters and points to a period-coded mixture of channels. A natural explanation is that most brown dwarfs originate from fragmentation at wider separations, with long-period systems retaining this stellar-like imprint, while only those embedded in massive, long-lived metal-rich protoplanetary disks are efficiently delivered and stabilized to short orbits.