Author: JJ Hermes

Planetary bodies observed for first time in habitable zone of dead star

In February 2022, a manuscript led by Jay Farihi from University College London and including members of the BUWD group (Farihi, Hermes, Marsh, et al. 2022) announced the discovery of a remarkable white dwarf that hosts the first planetary debris found in the habitable zone of a retired solar system. The white dwarf, WD1054-226, started […]

TESS finds 74 bright pulsating white dwarfs

In January 2022, a manuscript led by Alejandra Romero from the Universidade Federal do Rio Grande do Sul in Brazil announced the outcome of a large search for bright new pulsating white dwarfs: in the first three years of the TESS mission we have discovered 74 new pulsating hydrogen-atmosphere (ZZ Ceti) white dwarfs. The work […]

Preempting an ‘oops’ with JWST

In January 2022, Deputy Project Scientist for JWST Susan Mullally and members of the BUWD group announced the first results of a project to monitor nearly all possible spectrophotometric standards that are planned to calibrate the high-precision observations undertaken by the recently launched 6.5-meter James Webb Space Telescope. Using another NASA mission, TESS, we found […]

TESS watches a low-mass white dwarf pulsate

In October 2021, former BUWD group member Isaac Lopez led a global collaboration announcing the discovery, characterization with TESS, and asteroseismic modeling of the pulsations in the first extremely low-mass white dwarf observed from space: GD 278. Using a method to select variable white dwarfs from Gaia pioneered by our group, we first saw pulsations […]

A 99-min binary from SDSS-V

In one of the first science results from SDSS-V, collaborators led by Harvard graduate student Vedant Chandra have discovered a double-lined, double-white-dwarf binary orbiting one another every 99 minutes in a paper that was recently accepted for publication by the Astrophysical Journal. The two white dwarfs will merge into a roughly 0.85 solar-mass remnant in […]

Rotation in shrapnel from a supernova

In June 2021 work led by researchers in the BU White Dwarf group discovered that the partly burnt runaway star LP 40-365 (also known as GD 492) rotates every 8.9 hours using archival data from the Transiting Exoplanet Survey Satellite (TESS) and the Hubble Space Telescope (HST). This relatively long rotation period likes adds more […]

Debris orbiting a white dwarf every 9.9 hours

In June 2021, collaborators from all over the world led by UT-Austin graduate student Zach Vanderbosch characterized the orbital period of transiting debris around a new white dwarf: ZTF J0328−1219. The debris shows repeating dips that are stable from night-to-night and repeat every 9.937 hr (shown in the figure above over several nights), as well […]

Untangling mysterious emission in some cool white dwarfs

In March 2021 work led by University College London graduate student Nik Walters was accepted to MNRAS analyzing GD 356, the prototype of a new class of just four white dwarfs that exhibit Balmer emission lines despite being apparently isolated stars. Here we provide strong evidence that this emission is not the result of a […]

More transiting debris found in ZTF

In December 2020 work led by UT-Austin undergraduate student Joseph Guidry and collaborators was posted to arXiv announcing up to five new white dwarfs showing transiting debris from the Zwicky Transient Facility (ZTF), more than tripling the number of such systems known! That work was accepted for publication in March 2021 and will appear soon […]

Planetary debris transiting a second white dwarf

In July 2020, collaborators led by PhD student Zachary Vanderbosch at the University of Texas at Austin have published in The Astrophysical Journal only the second white dwarf known to show transits from an asteroid or planetesimal that got too close to its retired host star. The transits recur roughly every 100 days as the […]