An Eccentric Brown Dwarf Eclipsing an M dwarf

We report the discovery of an M = 67 ± 2M J brown dwarf transiting the early M dwarf TOI-2119 on an eccentric orbit (e = 0.3362 ± 0.0005) at an orbital period of 7.200861 ± 0.000005 days. We confirm the brown dwarf nature of the transiting companion using a combination of ground-based and space-based photometry and high-precision velocimetry from the Habitable-zone Planet Finder. Detection of the secondary eclipse with TESS photometry enables a precise determination of the eccentricity and reveals the brown dwarf has a brightness temperature of 2100 ± 80 K, a value which is consistent with an early L dwarf. TOI-2119 is one of the most eccentric known brown dwarfs with P < 10 days, possibly due to the long circularization timescales for an object orbiting an M dwarf. We assess the prospects for determining the obliquity of the host star to probe formation scenarios and the possibility of additional companions in the system using Gaia EDR3 and our radial velocities. © 2022. The American Astronomical Society. All rights reserved.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Sandstone cementation and fluids in hydrocarbon basins

Are porewater flow or stasis exclusive hypotheses? We think there is an intermediate view. Processes governing sandstone cementation in the deep sub-surface are elusive, case-specific and difficult to model in general terms. Combining techniques from petrography, isotopic and ion microprobe analyses with basin modelling one can narrow the possibilities towards unique hypotheses. Examples are given, predominantly from the North Sea basins, where palaeo-porewaters in different settings may evidence: (1) meteoric, compaction, or convection origins; (2) overpressured vertical leakoff; and (3) stasis and gt 100 m 'diffusion', helped by flow dispersion. Geochemical interaction transfers K and Al to muds, C to sands and forms secondary porosity by feldspar loss at depth, late carbonates, and hairy illite Chat can date oil charge

TOI-532b: The Habitable-zone Planet Finder confirms a Large Super Neptune in the Neptune Desert orbiting a metal-rich M-dwarf host

We confirm the planetary nature of TOI-532b, using a combination of precise near-infrared radial velocities with the Habitable-zone Planet Finder, Transiting Exoplanet Survey Satellite (TESS) light curves, ground-based photometric follow up, and high-contrast imaging. TOI-532 is a faint (J ∼ 11.5) metal-rich M dwarf with Teff = 3957 ± 69 K and [Fe/H] = 0.38 ± 0.04; it hosts a transiting gaseous planet with a period of ∼2.3 days. Joint fitting of the radial velocities with the TESS and ground-based transits reveal a planet with radius of 5.82 ± 0.19 R ⊕, and a mass of 61.5-9.3+9.7 M ⊕. TOI-532b is the largest and most massive super Neptune detected around an M dwarf with both mass and radius measurements, and it bridges the gap between the Neptune-sized planets and the heavier Jovian planets known to orbit M dwarfs. It also follows the previously noted trend between gas giants and host-star metallicity for M-dwarf planets. In addition, it is situated at the edge of the Neptune desert in the Radius-Insolation plane, helping place constraints on the mechanisms responsible for sculpting this region of planetary parameter space. © 2021. The American Astronomical Society. All rights reserved.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]