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Mark Clampin

Publications and source records attributed to Mark Clampin.

10 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2024

JWST-TST High Contrast: Asymmetries, Dust Populations, and Hints of a Collision in the β Pictoris Disk with NIRCam and MIRI

We present the first JWST Mid-Infrared Instrument (MIRI) and Near Infrared Camera (NIRCam) observations of the prominent debris disk around βPictoris. Coronagraphic observations in eight filters spanning from 1.8 to 23 μm provide an unprecedentedly clear view of the disk at these wavelengths. The objectives of the observing program were to investigate the dust composition and distribution and to investigate the presence of planets in the system. In this paper, we focus on the disk components, providing surface brightness measurements for all images and a detailed investigation of the asymmetries observed. A companion paper by Kammerer et al. will focus on the planets in this system using the same data. We report for the first time the presence of an extended secondary disk in thermal emission, with a curved extension bent away from the plane of the disk. This feature, which we refer to as the “cat’s tail,” seems to be connected with the previously reported CO clump, mid-infrared asymmetry detected on the southwest side of the disk, and the warp observed in scattered light. We present a model of this secondary disk sporadically producing dust that broadly reproduces the morphology, flux, and color of the cat’s tail, as well as other features observed in the disk, and which suggests the secondary disk is composed largely of porous, organic refractory dust grains.

Isabel Rebollido↗
NASA NTRS2023

The James Webb Space Telescope Mission: Optical Telescope Element Design, Development, and Performance

The James Webb Space Telescope (JWST) is a large, infrared space telescope that has recently started its science program which will enable breakthroughs in astrophysics and planetary science. Notably, JWST will provide the very first observations of the earliest luminous objects in the universe and start a new era of exoplanet atmospheric characterization. This transformative science is enabled by a 6.6 m telescope that is passively cooled with a 5 layer sunshield. The primary mirror is comprised of 18 controllable, low areal density hexagonal segments, that were aligned and phased relative to each other in orbit using innovative image-based wave front sensing and control algorithms. This revolutionary telescope took more than two decades to develop with a widely distributed team across engineering disciplines. We present an overview of the telescope requirements, architecture, development, superb on-orbit performance, and lessons learned. JWST successfully demonstrates a segmented aperture space telescope and establishes a path to building even larger space telescopes.

Infrared observatories↗
NASA NTRS2023

How Dark the Sky: The JWST Backgrounds

We describe the sources of stray light and thermal background that affect JWST observations; report actual backgrounds as measured from commissioning and early science observations; compare those background levels to pre-launch predictions; estimate the impact of the backgrounds on science performance; and explore how the backgrounds probe the achieved configuration of the deployed observatory. We find the observatory is limited by the irreducible astrophysical backgrounds, rather than scattered stray light and thermal self-emission, for all wavelengths λ<12.5 micron, thus meeting the level 1 requirement. This result was not assured given the open architecture and thermal challenges of JWST, and is the result of meticulous attention to stray light and thermal issues in the design, construction, integration, and test phases. From background considerations alone, JWST will require less integration time in the near-infrared compared to a system that just met the stray light requirements; as such, JWST will be even more powerful than expected for deep imaging at 1--5 micron. In the mid-infrared, the measured thermal backgrounds closely match pre-launch predictions. The background near 10 micron is slightly higher than predicted before launch, but the impact on observations is mitigated by the excellent throughput of MIRI, such that instrument sensitivity will be as good as expected pre-launch. These measured background levels are fully compatible with JWST's science goals and the Cycle 1 science program currently underway.

Astronomical instrumentation↗
NASA NTRS2023

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.

Infrared astronomy↗
NASA NTRS2019

The L 98-59 System: Three Transiting, Terrestrial-size Planets Orbiting a Nearby M Dwarf

We report the Transiting Exoplanet Survey Satellite (TESS) discovery of three terrestrial-size planets transiting L98-59 (TOI-175, TIC 307210830)—a bright M dwarf at a distance of 10.6 pc. Using the Gaia-measured distance and broadband photometry, we find that the host star is an M3 dwarf. Combined with the TESS transits from three sectors, the corresponding stellar parameters yield planet radii ranging from 0.8 R⊕ to 1.6 R⊕. All three planets have short orbital periods, ranging from 2.25 to 7.45 days with the outer pair just wide of a 2:1 period resonance. Diagnostic tests produced by the TESS Data Validation Report and the vetting package DAVE rule out common false-positive sources. These analyses, along with dedicated follow-up and the multiplicity of the system, lend confidence that the observed signals are caused by planets transiting L 98-59 and are not associated with other sources in the field. The L 98-59 system is interesting for a number of reasons: the host star is bright (V =11.7 mag, K = 7.1 mag) and the planets are prime targets for further follow-up observations including precision radial-velocity mass measurements and future transit spectroscopy with the James Webb Space Telescope; the near-resonant configuration makes the system a laboratory to study planetary system dynamical evolution; and three planets of relatively similar size in the same system present an opportunity to study terrestrial planets where other variables (age, metallicity, etc.) can be held constant. L 98-59 will be observed in four more TESS sectors, which will provide a wealth of information on the three currently known planets and have the potential to reveal additional planets in the system.

planets↗
NASA NTRS2019

The L 98-59 System Three Transiting, Terrestrial-size Planets Orbiting a Nearby M Dwarf

We report the Transiting Exoplanet Survey Satellite (TESS) discovery of three terrestrial-size planets transiting L 98-59 (TOI-175, TIC 307210830)—a bright M dwarf at a distance of 10.6 pc. Using the Gaia-measured distance and broadband photometry, we find that the host star is an M3 dwarf. Combined with the TESS transits from three sectors, the corresponding stellar parameters yield planet radii ranging from 0.8 R⊕ to 1.6 R⊕. All three planets have short orbital periods, ranging from 2.25 to 7.45 days with the outer pair just wide of a 2:1 period resonance. Diagnostic tests produced by the TESS Data Validation Report and the vetting package DAVE rule out common false-positive sources. These analyses, along with dedicated follow-up and the multiplicity of the system, lend confidence that the observed signals are caused by planets transiting L 98-59 and are not associated with other sources in the field. The L 98-59 system is interesting for a number of reasons: the host star is bright (V = 11.7 mag, K = 7.1 mag) and the planets are prime targets for further follow-up observations including precision radial-velocity mass measurements and future transit spectroscopy with the James Webb Space Telescope; the near-resonant configuration makes the system a laboratory to study planetary system dynamical evolution; and three planets of relatively similar size in the same system present an opportunity to study terrestrial planets where other variables (age, metallicity, etc.) can be held constant. L 98-59 will be observed in four more TESS sectors, which will provide a wealth of information on the three currently known planets and have the potential to reveal additional planets in the system.

Veselin B Kostov↗
NASA NTRS2012

Space Telescope Sensitivity and Controls for Exoplanet Imaging

Herein we address design considerations and outline requirements for space telescopes with capabilities for high contrast imaging of exoplanets. The approach taken is to identify the span of potentially detectable Earth-sized terrestrial planets in the habitable zone of the nearest stars within 30 parsecs and estimate their inner working angles, flux ratios, SNR, sensitivities, wavefront error requirements and sensing and control times parametrically versus aperture size. We consider 1, 2, 4, 8 and 16-meter diameter telescope apertures. The achievable science, range of telescope architectures, and the coronagraphic approach are all active areas of research and are all subject to change in a rapidly evolving field. Thus, presented is a snapshot of our current understanding with the goal of limiting the choices to those that appear currently technically feasible. We describe the top-level metrics of inner working angle, contrast and photometric throughput and explore how they are related to the range of target stars. A critical point is that for each telescope architecture and coronagraphic choice the telescope stability requirements have differing impacts on the design for open versus closed-loop sensing and control.

Wavefront control↗
NASA NTRSDate not supplied

Establishing a Resilient Flagships Science Program

We are at a crossroads today with large and complex missions, known as flagships: while much has been achieved to lower their size, weight, and power demands, there are science questions that cannot be answered but through the exquisite measurements characteristic of flagships. We need an approach to a resilient flagships program for science: One, conduct an assessment of the fundamental science questions and concept feasibility study to define the core science requirements (those that, if not met, render the mission unnecessary), and the corresponding technology challenges.

Francesco Bordi↗
NASA NTRSDate not supplied

The TESS Mission Target Selection Procedure

We describe the target selection procedure by which stars are selected for 2 minute and 20 s observations by TESS. We first list the technical requirements of the TESS instrument and ground systems processing that limit the total number of target slots. We then describe algorithms used by the TESS Payload Operation Center (POC) to merge candidate targets requested by the various TESS mission elements (the Target Selection Working Group, TESS Asteroseismic Science Consortium, and Guest Investigator office). Lastly, we summarize the properties of the observed TESS targets over the two-year primary TESS mission. We find that the POC target selection algorithm results in 2.1–3.4 times as many observed targets as target slots allocated for each mission element. We also find that the sky distribution of observed targets is different from the sky distributions of candidate targets due to technical constraints that require a relatively even distribution of targets across the TESS fields of view. We caution researchers exploring statistical analyses of TESS planet-host stars that the population of observed targets cannot be characterized by any simple set of criteria applied to the properties of the input Candidate Target Lists.

Michael Fausnaugh↗