Explanipedia

An Ultra-hot Low-mass Brown Dwarf Eclipsing the Puffy White Dwarf J0404+1112 Open

Julien de Wit, R. Alonso, Benjamin V. Rackham, Susan M. Lederer, Artem Burdanov , et al. · 2025

Most exoplanets known orbit stars that will evolve into red giants, then white dwarfs (WDs). Understanding the population of substellar WD companions informs the common-envelope evolution process (E. Villaver & M. Livio 2009), thereby shed…

Hubble's Multi-Year Search for Exospheres in the TRAPPIST-1 System Reveals Frequent Microflares Open

David Berardo, Julien de Wit, M. Gillon, Ward S. Howard, V. Bourrier , et al. · 2025

Ly-$α$ observations provide a powerful probe of stellar activity and atmospheric escape in exoplanetary systems. We present here an analysis of 104 HST/STIS orbits monitoring the TRAPPIST-1 system between 2017 and 2022, covering 3--5 trans…

Detection of an Earth-sized exoplanet orbiting the nearby ultracool dwarf star SPECULOOS-3 Open

M. Gillon, Peter P. Pedersen, Benjamin V. Rackham, Georgina Dransfield, Elsa Ducrot , et al. · 2024

An Earth-sized exoplanet ripe for emission spectroscopy with JWST in orbit around a nearby ultracool dwarf star Open

M. Gillon, P. P. Pedersen, Benjamin V. Rackham, Georgina Dransfield, Elsa Ducrot , et al. · 2023

The JWST space telescope has the potential to measure the emission spectrum of a highly irradiated exoplanet as small as the Earth, especially if it transits a very nearby and cold star similar in size to Jupiter. Such ‘ultracool dwarf sta…

Refining the Transit-timing and Photometric Analysis of TRAPPIST-1: Masses, Radii, Densities, Dynamics, and Ephemerides Open

Eric Agol, Caroline Dorn, Simon L. Grimm, Martin Turbet, Elsa Ducrot , et al. · 2021

We have collected transit times for the TRAPPIST-1 system with the Spitzer Space Telescope over four years. We add to these ground-based, HST, and K2 transit-time measurements, and revisit an N -body dynamical analysis of the seven-planet …

Refining the transit timing and photometric analysis of TRAPPIST-1: Masses, radii, densities, dynamics, and ephemerides Open

Eric Agol, Caroline Dorn, Simon L. Grimm, Martin Turbet, Elsa Ducrot , et al. · 2020

We have collected transit times for the TRAPPIST-1 system with the Spitzer Space Telescope over four years. We add to these ground-based, HST and K2 transit time measurements, and revisit an N-body dynamical analysis of the seven-planet sy…

data/ directory associated with https://github.com/ericagol/TRAPPIST1_Spitzer Open

Eric Agol, Caroline Dorn, Simon L. Grimm, Martin Turbet, Elsa Ducrot , et al. · 2020

Data directory for the repository associated with the paper "Refining the transit timing and photometric analysis of TRAPPIST-1: Masses, radii, densities, dynamics, and ephemerides."

data/ directory associated with https://github.com/ericagol/TRAPPIST1_Spitzer Open

Eric Agol, Caroline Dorn, Simon L. Grimm, Martin Turbet, Elsa Ducrot , et al. · 2020

Data directory for the repository associated with the paper "Refining the transit timing and photometric analysis of TRAPPIST-1: Masses, radii, densities, dynamics, and ephemerides."

TRAPPIST-1: Global results of the Spitzer Exploration Science Program Red Worlds★ Open

Elsa Ducrot, M. Gillon, L. Delrez, Eric Agol, Paul B. Rimmer , et al. · 2020

Context. With more than 1000 h of observation from Feb. 2016 to Oct. 2019, the Spitzer Exploration Program Red Worlds (ID: 13067, 13175 and 14223) exclusively targeted TRAPPIST-1, a nearby (12 pc) ultracool dwarf star, finding that it is o…

NASA's Orbital Debris JAO/ES-MCAT Optical Telescope Facility on Ascension Island Open

Susan M. Lederer, B. Buckalew, Paul Hickson · 2019

The NASA Orbital Debris Program Office has a long-standing optical program begun over three and a half decades ago in 1984, designed to observe the Earth-orbiting environment with optical telescopes. Photometrically calibrated optical data…

Ground-based follow-up observations of TRAPPIST-1 transits in the near-infrared Open

Artem Burdanov, Susan M. Lederer, M. Gillon, L. Delrez, Elsa Ducrot , et al. · 2019

The TRAPPIST-1 planetary system is a favourable target for the atmospheric characterization of temperate earth-sized exoplanets by means of transmission spectroscopy with the forthcoming James Webb Space Telescope (JWST). A possible obstac…

Disentangling the Planet from the Star in Late-Type M Dwarfs: A Case Study of TRAPPIST-1g Open

Hannah R. Wakeford, Nikole K. Lewis, J. Fowler, G. Bruno, Tom J. Wilson , et al. · 2018

The atmospheres of late M stars represent a significant challenge in the characterization of any transiting exoplanets because of the presence of strong molecular features in the stellar atmosphere. TRAPPIST-1 is an ultracool dwarf, host t…

Vis-NIR disk-integrated photometry of asteroid 25143 Itokawa around opposition by AMICA/Hayabusa Open

Eri Tatsumi, D. L. Domingue, Naru Hirata, K. Kitazato, F. Vilas , et al. · 2018

The nature of the TRAPPIST-1 exoplanets Open

Simon L. Grimm, Brice-Olivier Demory, M. Gillon, Caroline Dorn, Eric Agol , et al. · 2018

Context. The TRAPPIST-1 system hosts seven Earth-sized, temperate exoplanets orbiting an ultra-cool dwarf star. As such, it represents a remarkable setting to study the formation and evolution of terrestrial planets that formed in the same…

Atmospheric reconnaissance of the habitable-zone Earth-sized planets orbiting TRAPPIST-1 Open

Julien de Wit, Hannah R. Wakeford, Nikole K. Lewis, L. Delrez, M. Gillon , et al. · 2018

Early 2017 observations of TRAPPIST-1 with Spitzer Open

L. Delrez, M. Gillon, A. H. M. J. Triaud, Brice-Olivier Demory, Julien de Wit , et al. · 2018

The recently detected TRAPPIST-1 planetary system, with its seven planets transiting a nearby ultracool dwarf star, offers the first opportunity to perform comparative exoplanetology of temperate Earth-sized worlds. To further advance our …

The UKIRT Hemisphere Survey: definition and J-band data release Open

S. Dye, A. Lawrence, Mike Read, Xiaohui Fan, Tom Kerr , et al. · 2017

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. ©: 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

Characterizing Non-Resolved Debris Through Spectral and Photometric Ground-Based Telescopic Data: What Can Laboratory Ground-truth Data Do for You? Open

Susan M. Lederer · 2017

NASA's ODPO has recently collected data of unresolved objects at GEO with the 3.8m UKIRT infrared telescope on Mauna Kea and the 1.3m MCAT visible telescope on Ascension Island. Analyses of SWIR data of rocket bodies and HS-376 solar-panel…

Temporal evolution of the high-energy irradiation and water content of TRAPPIST-1 exoplanets Open

V. Bourrier, Émeline Bolmont, V. Stamenković, P. J. Wheatley, Adam J. Burgasser , et al. · 2017

The ultracool dwarf star TRAPPIST-1 hosts seven Earth-size transiting planets, some of which could harbour liquid water on their surfaces. UV observations are essential to measure their high-energy irradiation, and to search for photodisso…

United Kingdom Infrared Telescope's Spectrograph Observations of Human-Made Space Objects Open

B. Buckalew, Kira J. Abercromby, Susan M. Lederer, Heather Cowardin, James Frith · 2017

Presented here are the results of the United Kingdom Infrared Telescope (UKIRT) spectral observations of human-made space objects taken from 2014 to 2015. The data collected using the UKIRT 1-5 micron Imager Spectrometer (UIST) cover the w…

A terrestrial-sized exoplanet at the snow line of TRAPPIST-1 Open

Rodrigo Luger, Marko Sestovic, Ethan Kruse, Simon L. Grimm, Brice-Olivier Demory , et al. · 2017

The TRAPPIST-1 system is the first transiting planet system found orbiting an ultra-cool dwarf star. At least seven planets similar to Earth in radius and in mass were previously found to transit this host star. Subsequently, TRAPPIST-1 wa…

Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1 Open

M. Gillon, A. H. M. J. Triaud, Brice-Olivier Demory, Emmanuël Jehin, Eric Agol , et al. · 2017

Characterization of the High-Albedo NEA 3691 Bede Open

D. H. Wooden, Susan M. Lederer, Emmanuël Jehin, B. Rozitis, Jeffrey D. Jefferson , et al. · 2016

Characterization of NEAs provides important inputs to models for atmospheric entry, risk assessment and mitigation. Diameter is a key parameter because diameter translates to kinetic energy in atmospheric entry. Diameters can be derived fr…

A combined transmission spectrum of the Earth-sized exoplanets TRAPPIST-1 b and c Open

Julien de Wit, Hannah R. Wakeford, M. Gillon, Nikole K. Lewis, Jeff A. Valenti , et al. · 2016

Development of the NASA MCAT Auxiliary Telescope for Orbital Debris Research Open

James Frith, Susan M. Lederer, Heather Cowardin, B. Buckalew, Paul Hickson , et al. · 2016

The National Aeronautical Space Administration has deployed the Meter Class Autonomous Telescope (MCAT) to Ascension Island with plans for it to become fully operational by summer 2016. This telescope will be providing data in support of r…

Temperate Earth-sized planets transiting a nearby ultracool dwarf star Open

M. Gillon, Emmanuël Jehin, Susan M. Lederer, L. Delrez, Julien de Wit , et al. · 2016

Phase-Angle Dependence of Determinations of Diameter, Albedo, and Taxonomy: A case study of NEO 3691 Bede Open

D. H. Wooden, Susan M. Lederer, Emmanuël Jehin, E. S. Howell, Y. R. Fernández , et al. · 2015

Parameters important for NEO risk assessment and mitigation include Near-Earth Object diameter and taxonomic classification, which translates to surface composition. Diameters of NEOs are derived from the thermal fluxes measured by WISE, N…

Characterizing Debris in the Infrared with UKIRT Open

Susan M. Lederer, Moriba Jah, Richard L. Kendrick, B. Buckalew, James Frith , et al. · 2015

The United Kingdom Infrared Telescope (UKIRT) has been a major asset for the NASA Orbital Debris Program Office (OPDO) since March, 2014. With the UKIRT current contract coming to an end at the finish of FY15, there is a golden opportunity…

Observing Strategies for Focused, Faint Orbital Debris Surveys Using the Magellan Telescope Open

James Frith, Patrick Seitzer, P. Anz-Meador, Heather Cowardin, B. Buckalew , et al. · 2015

A breakup of the Titan 3C-17 Transtage rocket body was reported to have occurred on June 4th, 2014 at 02:38 UT by the Space Surveillance Network (SSN). Five objects were associated with this breakup and this is the fourth breakup known for…

NEAs: Phase Angle Dependence of Asteroid Class and Diameter from Observational Studies Open

D. H. Wooden, Susan M. Lederer, Schlete Bus, A. T. Tokunaga, Emmanuël Jehin , et al. · 2015

We will discuss the results of a planned observation campaign of Near Earth Asteroids (NEAs), 1999 CU3, 2002 GM2, 2002 FG7, and 3691 Bede with instruments on the United Kingdom Infrared Telescope (UKIRT) from 15-Mar-2015 to 28-April 2015 U…

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