Showing 1–7 of 7 results for author: Chickles, E

The Lightspeed project: high-speed, ultra-low read noise imaging and polarimetry for the Magellan telescopes

Authors: Christopher Layden, Kevin Burdge, John J. Piotrowski, Gabor Furesz, Juliana Garcia-Mejia, Jack Dinsmore, Roger W. Romani, David Osip, Geoffrey Mo, Vera Berger, Aaron Householder, Danielle Frostig, Emma T. Chickles, Emma Pellecer, Malina Desai

Abstract: Lightspeed will be an ultra-fast (> kHz), ultra-low read noise, multicolor (ugriz + IR) imager for the 6.5 meter Magellan Clay telescope. In a single-channel configuration, Lightspeed will also enable single-shot linear polarimetry, narrowband imaging, or white-light imaging. Lightspeed is designed around groundbreaking single-photon-resolving detector technologies: deep sub-electron read noise CM… ▽ More Lightspeed will be an ultra-fast (> kHz), ultra-low read noise, multicolor (ugriz + IR) imager for the 6.5 meter Magellan Clay telescope. In a single-channel configuration, Lightspeed will also enable single-shot linear polarimetry, narrowband imaging, or white-light imaging. Lightspeed is designed around groundbreaking single-photon-resolving detector technologies: deep sub-electron read noise CMOS image sensors from Fairchild Imaging and a HgCdTe avalanche photodiode array from Leonardo. Here we present Lightspeed's basic optical design concept, predict its on-sky performance, and highlight science cases that Lightspeed has the potential to revolutionize. Lightspeed builds upon the success of proto-Lightspeed, a single-channel prototype employing commercial-off-the-shelf re-imaging optics. proto-Lightspeed is now available as a PI instrument on the Clay telescope. We also discuss the current status of proto-Lightspeed and lessons learned from its commissioning, applicable to the development of Lightspeed and any other instrument seeking to integrate scientific CMOS image sensors. △ Less

Submitted 14 July, 2026; originally announced July 2026.

Comments: 11 pages, 6 figures. To appear in Proc. SPIE 14149, Ground-based and Airborne Instrumentation for Astronomy XI, paper 14149-89

Stars stably accreting from substellar objects

Authors: Aaron Householder, Kaitlyn Shin, Kevin B. Burdge, Thomas R. Marsh, Saul A. Rappaport, Kareem El-Badry, Joheen Chakraborty, Emma Chickles, Fei Dai, Matthew J. Graham, S. R. Kulkarni, Pablo Rodríguez-Gil, Andrew Vanderburg, Samuel Whitebook

Abstract: Substellar objects such as brown dwarfs and planets are generally expected to remain detached from their main-sequence host stars unless orbital decay or stellar expansion brings them into contact, leading to rapid engulfment and destruction. Such a fate is predicted for the Earth and other rocky planets in our solar system; however, in certain cases, theory also allows for stable long-lived mass… ▽ More Substellar objects such as brown dwarfs and planets are generally expected to remain detached from their main-sequence host stars unless orbital decay or stellar expansion brings them into contact, leading to rapid engulfment and destruction. Such a fate is predicted for the Earth and other rocky planets in our solar system; however, in certain cases, theory also allows for stable long-lived mass transfer from a substellar object onto its main-sequence host, though such accretion has never been directly observed. Here we report the first direct observations of stable mass transfer from a substellar object onto a main-sequence star. In particular, we identify two binaries, ZTF J0440+2325 and ZTF J1444+4820, with orbital periods of just 87 and 67 minutes, respectively, in which a brown dwarf stably transfers mass onto an M dwarf companion. These systems demonstrate that the fate of some substellar objects is not rapid engulfment and destruction, but instead gradual consumption for potentially billions of years. △ Less

Submitted 17 March, 2026; originally announced March 2026.

Comments: 29 pages, 10 figures (3 main + 7 extended data), 1 table. Submitted to Nature Astronomy

proto-Lightspeed: a high-speed, ultra-low read noise imager on the Magellan Clay Telescope

Authors: Christopher Layden, Kevin Burdge, Gabor Furesz, Juliana Garcia-Mejia, Jack Dinsmore, Geoffrey Mo, David Osip, John J. Piotrowski, Roger W. Romani, August Berne, Deepto Chakrabarty, Emma Chickles

Abstract: proto-Lightspeed is a new instrument that has been commissioned on the Nasmyth East port of the Magellan Clay Telescope at Las Campanas Observatory to deliver high-speed optical imaging with deep sub-electron read noise. Making use of commercial re-imaging lenses and the ORCA-Quest 2 camera from Hamamatsu, proto-Lightspeed images a field $1'$ in diameter at up to $200$ Hz or windowed fields at hig… ▽ More proto-Lightspeed is a new instrument that has been commissioned on the Nasmyth East port of the Magellan Clay Telescope at Las Campanas Observatory to deliver high-speed optical imaging with deep sub-electron read noise. Making use of commercial re-imaging lenses and the ORCA-Quest 2 camera from Hamamatsu, proto-Lightspeed images a field $1'$ in diameter at up to $200$ Hz or windowed fields at higher rates, up to 6600 Hz for a $1.6''\times 1'$ field of view. proto-Lightspeed delivers seeing-limited image quality in the $g'$, $r'$, and $i'$ bands and adjustable magnification for pixel scales between $0.017''-0.050''$. proto-Lightspeed is well suited to studying compact binary systems, exoplanet transits, rapid flaring associated with accretion, periodic optical emission from pulsars, occultations of background stars by small trans-Neptunian Objects, and any other rapidly variable source. proto-Lightspeed will be a P.I. instrument beginning in 2026B, available for use by members of the Magellan Consortium. In this paper, we discuss the design and performance of the instrument, results from its two commissioning runs, and plans for a facility instrument, Lightspeed, to support simultaneous multicolor imaging across a $7'\times4'$ field. △ Less

Submitted 18 May, 2026; v1 submitted 22 January, 2026; originally announced January 2026.

Comments: Submitted to the Publications of the Astronomical Society of the Pacific

An eclipsing 8.56 minute orbital period mass-transferring binary

Authors: Emma T. Chickles, Joheen Chakraborty, Kevin B. Burdge, Vik S. Dhillon, Paul Draghis, Kareem El-Badry, Matthew J. Green, Aaron Householder, Sarah Hughes, Christopher Layden, Stuart P. Littlefair, James Munday, Ingrid Pelisoli, Maya S. Redden, John Tonry, Jan van Roestel, F. Elio Angile, Alex J. Brown, Noel Castro Segura, Jack Dinsmore, Martin Dyer, Gabor Furesz, Michelle Gabutti, James Garbutt, Juliana García-Mejía , et al. (12 additional authors not shown)

Abstract: We report the discovery of ATLAS J101342.5-451656.8 (hereafter ATLAS J1013-4516), an 8.56 minute orbital period mass transferring AM Canum Venaticorum binary with mean Gaia magnitude G=19.51. The system was identified via periodic variability in Asteroid Terrestrial-impact Last Alert System light curves of Gaia white dwarf candidates. Follow-up spectroscopy with the Large Lenslet Array Magellan Sp… ▽ More We report the discovery of ATLAS J101342.5-451656.8 (hereafter ATLAS J1013-4516), an 8.56 minute orbital period mass transferring AM Canum Venaticorum binary with mean Gaia magnitude G=19.51. The system was identified via periodic variability in Asteroid Terrestrial-impact Last Alert System light curves of Gaia white dwarf candidates. Follow-up spectroscopy with the Large Lenslet Array Magellan Spectrograph reveals a helium dominated accretion disk, while high speed ULTRACAM photometry shows pronounced primary and secondary eclipses. We construct a decade long orbital timing baseline using ATLAS and Gaia survey photometry together with high speed observations from ULTRACAM on the NTT and proto Lightspeed on the Magellan Clay telescope. From this baseline we measure an orbital period derivative Pdot = -1.60 +/- 0.07 x 10^-12 seconds per second. Interpreted in the context of stable mass transfer, the magnitude and sign of Pdot indicate orbital evolution governed by the interplay between gravitational wave driven angular momentum losses and mass transfer, directly probing the donor star structural response to mass loss. Assuming angular momentum loss dominated by gravitational radiation, we constrain the component masses and infer the characteristic gravitational wave strain. We predict a four year Laser Interferometer Space Antenna signal to noise ratio greater than 10, establishing ATLAS J1013-4516 as a strong prospective space based gravitational wave source that probes long term orbital evolution in the mass transferring regime. △ Less

Submitted 27 January, 2026; v1 submitted 12 January, 2026; originally announced January 2026.

Comments: 14 pages, 10 figures

A gravitational wave detectable candidate Type Ia supernova progenitor

Authors: Emma T. Chickles, Kevin B. Burdge, Joheen Chakraborty, Vik S. Dhillon, Paul Draghis, Scott A. Hughes, James Munday, Saul A. Rappaport, John Tonry, Evan Bauer, Alex Brown, Noel Castro, Deepto Chakrabarty, Martin Dyer, Kareem El-Badry, Anna Frebel, Gabor Furesz, James Garbutt, Matthew J. Green, Aaron Householder, Daniel Jarvis, Erin Kara, Mark R. Kennedy, Paul Kerry, Stuart P Littlefair , et al. (15 additional authors not shown)

Abstract: Type Ia supernovae, critical for studying cosmic expansion, arise from thermonuclear explosions of white dwarfs, but their precise progenitor pathways remain unclear. Growing evidence supports the ``double-degenerate'' scenario, where two white dwarfs interact. The absence of other companion types capable of explaining the observed Ia rate, along with observations of hyper-velocity white dwarfs in… ▽ More Type Ia supernovae, critical for studying cosmic expansion, arise from thermonuclear explosions of white dwarfs, but their precise progenitor pathways remain unclear. Growing evidence supports the ``double-degenerate'' scenario, where two white dwarfs interact. The absence of other companion types capable of explaining the observed Ia rate, along with observations of hyper-velocity white dwarfs interpreted as surviving companions of such systems provide compelling evidence in favor of this scenario. Upcoming millihertz gravitational wave observatories like the Laser Interferometer Space Antenna (LISA) are expected to detect thousands of double-degenerate systems, though the most compact known candidate Ia progenitors produce only marginally detectable gravitational wave signals. Here, we report observations of ATLAS J1138-5139, a binary white dwarf system with an orbital period of 28 minutes. Our analysis reveals a 1 solar mass carbon-oxygen white dwarf accreting from a helium-core white dwarf. Given its mass, the accreting carbon-oxygen white dwarf is poised to trigger a typical-luminosity Type Ia supernova within a few million years, or to evolve into a stably mass-transferring AM CVn system. ATLAS J1138-5139 provides a rare opportunity to calibrate binary evolution models by directly comparing observed orbital parameters and mass transfer rates closer to merger than any previously identified candidate Type Ia progenitor. Its compact orbit ensures detectability by LISA, demonstrating the potential of millihertz gravitational wave observatories to reveal a population of Type Ia progenitors on a Galactic scale, paving the way for multi-messenger studies offering insights into the origins of these cosmologically significant explosions. △ Less

Submitted 3 December, 2024; v1 submitted 29 November, 2024; originally announced November 2024.

Comments: 40 pages, 7 figures, 2 tables

Expanding the ultracompacts: gravitational wave-driven mass transfer in the shortest-period binaries with accretion disks

Authors: Joheen Chakraborty, Kevin B. Burdge, Saul A. Rappaport, James Munday, Hai-Liang Chen, Pablo Rodríguez-Gil, V. S. Dhillon, Scott A. Hughes, Gijs Nelemans, Erin Kara, Eric C. Bellm, Alex J. Brown, Noel Castro Segura, Tracy X. Chen, Emma Chickles, Martin J. Dyer, Richard Dekany, Andrew J. Drake, James Garbutt, Matthew J. Graham, Matthew J. Green, Dan Jarvis, Mark R. Kennedy, Paul Kerry, S. R. Kulkarni , et al. (13 additional authors not shown)

Abstract: We report the discovery of three ultracompact binary white dwarf systems hosting accretion disks, with orbital periods of 7.95, 8.68, and 13.15 minutes. This significantly augments the population of mass-transferring binaries at the shortest periods, and provides the first evidence that accretors in ultracompacts can be dense enough to host accretion disks even below 10 minutes (where previously o… ▽ More We report the discovery of three ultracompact binary white dwarf systems hosting accretion disks, with orbital periods of 7.95, 8.68, and 13.15 minutes. This significantly augments the population of mass-transferring binaries at the shortest periods, and provides the first evidence that accretors in ultracompacts can be dense enough to host accretion disks even below 10 minutes (where previously only direct-impact accretors were known). In the two shortest-period systems, we measured changes in the orbital periods driven by the combined effect of gravitational wave emission and mass transfer; we find $\dot{P}$ is negative in one case, and positive in the other. This is only the second system measured with a positive $\dot{P}$, and it the most compact binary known that has survived a period minimum. Using these systems as examples, we show how the measurement of $\dot{P}$ is a powerful tool in constraining the physical properties of binaries, e.g. the mass and mass-radius relation of the donor stars. We find that the chirp masses of ultracompact binaries at these periods seem to cluster around $\mathcal{M}_c \sim 0.3 M_\odot$, perhaps suggesting a common origin for these systems or a selection bias in electromagnetic discoveries. Our new systems are among the highest-amplitude known gravitational wave sources in the millihertz regime, providing exquisite opportunity for multi-messenger study with future space-based observatories such as \textit{LISA} and TianQin; we discuss how such systems provide fascinating laboratories to study the unique regime where the accretion process is mediated by gravitational waves. △ Less

Submitted 19 November, 2024; originally announced November 2024.

Comments: Accepted for publication in ApJ

Orbital decay in an accreting and eclipsing 13.7 minute orbital period binary with a luminous donor

Authors: Kevin B. Burdge, Kareem El-Badry, Saul Rappaport, Tin Long Sunny Wong, Evan B. Bauer, Lars Bildsten, Ilaria Caiazzo, Deepto Chakrabarty, Emma Chickles, Matthew J. Graham, Erin Kara, S. R. Kulkarni, Thomas R. Marsh, Melania Nynka, Thomas A. Prince, Robert A. Simcoe, Jan van Roestel, Zach Vanderbosch, Eric C. Bellm, Richard G. Dekany, Andrew J. Drake, George Helou, Frank J. Masci, Jennifer Milburn, Reed Riddle , et al. (2 additional authors not shown)

Abstract: We report the discovery of ZTF J0127+5258, a compact mass-transferring binary with an orbital period of 13.7 minutes. The system contains a white dwarf accretor, which likely originated as a post-common envelope carbon-oxygen (CO) white dwarf, and a warm donor ($T_{\rm eff,\,donor}= 16,400\pm1000\,\rm K$). The donor probably formed during a common envelope phase between the CO white dwarf and an e… ▽ More We report the discovery of ZTF J0127+5258, a compact mass-transferring binary with an orbital period of 13.7 minutes. The system contains a white dwarf accretor, which likely originated as a post-common envelope carbon-oxygen (CO) white dwarf, and a warm donor ($T_{\rm eff,\,donor}= 16,400\pm1000\,\rm K$). The donor probably formed during a common envelope phase between the CO white dwarf and an evolving giant which left behind a helium star or helium white dwarf in a close orbit with the CO white dwarf. We measure gravitational wave-driven orbital inspiral with $\sim 35σ$ significance, which yields a joint constraint on the component masses and mass transfer rate. While the accretion disk in the system is dominated by ionized helium emission, the donor exhibits a mixture of hydrogen and helium absorption lines. Phase-resolved spectroscopy yields a donor radial-velocity semi-amplitude of $771\pm27\,\rm km\, s^{-1}$, and high-speed photometry reveals that the system is eclipsing. We detect a {\it Chandra} X-ray counterpart with $L_{X}\sim 3\times 10^{31}\,\rm erg\,s^{-1}$. Depending on the mass-transfer rate, the system will likely evolve into either a stably mass-transferring helium CV, merge to become an R Crb star, or explode as a Type Ia supernova in the next million years. We predict that the Laser Space Interferometer Antenna (LISA) will detect the source with a signal-to-noise ratio of $24\pm6$ after 4 years of observations. The system is the first \emph{LISA}-loud mass-transferring binary with an intrinsically luminous donor, a class of sources that provide the opportunity to leverage the synergy between optical and infrared time domain surveys, X-ray facilities, and gravitational-wave observatories to probe general relativity, accretion physics, and binary evolution. △ Less

Submitted 23 March, 2023; originally announced March 2023.

Comments: 13 pages, 7 figures, 2 tables, submitted to ApJL