Steven Cranmer

About

Steven Cranmer is a professor in the Astrophysical & Planetary Sciences department at the University of Colorado Boulder. His research interests include solar and stellar astrophysics, with a focus on the heating and energization of particles in the solar corona, the acceleration of the solar wind, and waves and turbulence in various astrophysical plasmas. Cranmer studies the hot, expanding outer atmosphere of the Sun to better understand and predict the Sun's long-term effects on Earth's climate and local space environment. His work also encompasses radiative transfer in stellar atmospheres, kinetic plasma physics, the dynamics of winds from rotating hot stars such as O, B, and Wolf-Rayet types, and nonradial stellar pulsations. Cranmer has contributed to the scientific community through publications on topics like magnetohydrodynamic mode conversion in the solar corona, stellar mass loss, and the properties of the solar corona and its connection to the solar wind.

Research topics

• Political Science
• Computer Science
• Physics
• Engineering
• Astronomy
• Systems engineering
• History

Selected publications

• Critical Science Plan for the Daniel K. Inouye Solar Telescope (DKIST)

  Solar Physics · 2021 · 107 citations

  Abstract The National Science Foundation’s Daniel K. Inouye Solar Telescope (DKIST) will revolutionize our ability to measure, understand, and model the basic physical processes that control the structure and dynamics of the Sun and its atmosphere. The first-light DKIST images, released publicly on 29 January 2020, only hint at the extraordinary capabilities that will accompany full commissioning of the five facility instruments. With this Critical Science Plan (CSP) we attempt to anticipate som…

  PublisherOA PDFDOI

• CONSTRAINTS on PLANETESIMAL COLLISION MODELS in DEBRIS DISKS

  Figshare · 2024-01-01 · 52 citations

  articleOpen access

  Observations of debris disks offer a window into the physical and dynamical properties of planetesimals in extrasolar systems through the size distribution of dust grains. In particular, the millimeter spectral index of thermal dust emission encodes information on the grain size distribution. We have made new VLA observations of a sample of seven nearby debris disks at 9 mm, with 3" resolution and ~5 μJy beam−1rms. We combine these with archival ATCA observations of eight additional debris disks…

  PublisherDOI

• The Sun’s Alfvén Surface: Recent Insights and Prospects for the Polarimeter to Unify the Corona and Heliosphere (PUNCH)

  Solar Physics · 2023-11-01 · 20 citations

  articleOpen access1st authorCorresponding

  Abstract The solar wind is the extension of the Sun’s hot and ionized corona, and it exists in a state of continuous expansion into interplanetary space. The radial distance at which the wind’s outflow speed exceeds the phase speed of Alfvénic and fast-mode magnetohydrodynamic (MHD) waves is called the Alfvén radius. In one-dimensional models, this is a singular point beyond which most fluctuations in the plasma and magnetic field cannot propagate back down to the Sun. In the multi-dimensional s…

  PublisherOA PDFDOI

• Estimates of Proton and Electron Heating Rates Extended to the Near-Sun Environment

  The Astrophysical Journal Letters · 2023-09-26 · 15 citations

  articleOpen access

  Abstract A central problem of space plasma physics is how protons and electrons are heated in a turbulent, magnetized plasma. The differential heating of charged species due to dissipation of turbulent fluctuations plays a key role in solar wind evolution. Measurements from previous heliophysics missions have provided estimates of proton and electron heating rates beyond 0.27 au. Using Parker Solar Probe (PSP) data accumulated during the first 10 encounters, we extend the evaluation of the indiv…

  PublisherOA PDFDOI

• High-frequency Coronal Alfvénic Waves Observed with DKIST/Cryo-NIRSP

  The Astrophysical Journal · 2025-03-21 · 13 citations

  articleOpen access

  Abstract The presence and nature of low-frequency (0.1–10 mHz) Alfvénic waves in the corona have been established over the past decade, with many of these results coming from coronagraphic observations of the infrared Fe xiii line. The Cryo-NIRSP instrument situated at DKIST has recently begun acquiring science-quality data of the same Fe xiii line, with at least a factor of 9 improvement in spatial resolution, a factor of 30 increase in temporal resolution, and an increase in signal-to-noise ra…

  PublisherDOI

Recent grants

• Coronal Turbulence Driven from the Sun's Photosphere: Preparing for the Era of the Daniel K. Inouye Solar Telescope

  NSF · $279k · 2016–2022

• SHINE: Accelerating the Turbulent Solar Wind: One Flux Tube at a Time

  NSF · $193k · 2013–2015

• SHINE: Accelerating the Turbulent Solar Wind: One Flux Tube at a Time

  NSF · $193k · 2014–2019

Frequent coauthors

• J. C. Raymond

  Center for Astrophysics Harvard & Smithsonian

  52 shared

• M. P. Miralles

  Center for Astrophysics Harvard & Smithsonian

  48 shared

• S. E. Gibson

  NSF National Center for Atmospheric Research

  47 shared

• J. L. Kohl

  45 shared

• S. P. Owocki

  University of Delaware

  34 shared

• M. Maksimović

  Université de Versailles Saint-Quentin-en-Yvelines

  33 shared

• L. Strachan

  33 shared

• A. V. Panasyuk

  31 shared

Education

• Ph.D., Physics & Astronomy

  University of Delaware

  1996

• M.S., Astronomy

  Ohio State University

  1991

• B.S., Physics & Atmospheric Science

  Drexel University

  1990

Similar researchers at University of Colorado Boulder

• Daniel Bakerh-132
• Andrew Hamiltonh-122
• Nils Halversonh-80