Author: JJ Hermes

Transits (that vanish) around a white dwarf every 4.97 hr

In August 2025, a manuscript led by graduate student and BUWD member Joseph Guidry (Guidry, Vanderbosch, Hermes et al. 2025) was accepted which announced the discovery of deep, irregular, periodic transits from rocky exoplanetary debris towards the white dwarf ZTF J1944+4557. This retired star dims by more than 30% roughly every five hours, as clumps […]

Gravitational redshift bias in white dwarf spectra

In August 2025, a manuscript led by graduate student and BUWD member Stefan Arseneau (Arseneau, Hermes, Zakamska et al. 2025) was accepted which showed that substantial biases (5-15 km/s) exist in low-resolution radial velocity measurements, indicating that all the physics of line formation in high-density plasmas is not fully accounted for in state-of-the-art white dwarf […]

NASA’s Hubble Uncovers Rare White Dwarf Merger Remnant

In August 2025, a manuscript led by Snehalata Sahu at the University of Warwick and including members of the BUWD group (Sahu et al. 2025) announced the discovery of carbon in the atmosphere of an otherwise normal-looking hot hydrogen-rich white dwarf, a tell-tale sign of a merger in the history of the system. The discovery […]

Probing Exoplanets Around Massive Stars

In November 2024, a manuscript led by graduate student and BUWD member Lou Baya Ould Rouis (Ould Rouis, Hermes, Gaensicke et al. 2024) was accepted which showed that the most massive white dwarfs (>0.8 solar masses) show metal pollution significantly less frequently than more normal-mass white dwarfs. Specifically, just 11% of white dwarfs that begin […]

Written in the Stars

A story we ❤️about how exploring the Universe can re-ignite passion. And we don't mind that it's about looking at our white dwarf spectra in @jjhermes.bsky.social group 🤩🔭 www.bu.edu/articles/202… [image or embed] — Sloan Digital Sky Surveys (@sdssurveys.bsky.social) December 12, 2024 at 3:58 PM BU White Dwarf researcher Ariyana Bonab was featured in a November […]

Signposts of Remnant Planetary Systems

In June 2024, a manuscript led by graduate student and BUWD member Joseph Guidry (Guidry, Hermes, De et al. 2024) took a look at infrared variability of white dwarfs as seen over many years from NASA’s Wide-field Infrared Survey Explorer (WISE) space telescope, discovering dozens of new infrared-variable white dwarfs that are likely to be […]

Dr. Tyler Heintz

Massive congratulations to Dr. Tyler Heintz, who successfully defended his PhD dissertation on Tuesday July 23, 2024! Tyler has been at BU throughout the entire history of the BUWD research group, and has become expert in the reliability of white dwarf cosmochronology (age-dating white dwarf stars).

EuroWD Conference, July 2024

Three members of the BU White Dwarf group attended the 23rd European Workshop on White Dwarfs, held in July 2024 in Barcelona. We will be hosting the 24th meeting in Summer 2026 in Boston!

Testing Ages Using Spectroscopy of White Dwarfs

In May 2024, a manuscript led by graduate student and BUWD member Tyler Heintz (Heintz, Hermes, Tremblay et al. 2024) announced the most detailed test of white dwarf ages measured from spectroscopic fits in wide WD+WD binaries. By comparing the age estimates of wide pairs of stars that should have both been born at the […]

Gaia’s Light Curve Prospects

In April 2024, a manuscript led by former BU undergraduate student and BUWD member Maya Steen (Steen, Hermes, Guidry et al. 2024) detailed one of the first systematic analyses of Gaia DR3 multi-epoch light curves, this focused on white dwarfs. Roughly 1300 candidate white dwarfs have Gaia light curves (spanning roughly 1000 days with visits […]