1. Automated Feature Detection and Analysis for SDO and Other Solar Observatories
Our website details every of the 16 modules and has lots of images and movies
MSU Personnel involved: Piet Martens,
Rafal Angryk (Computer Science)
Postdocs: Juan Banda and
Jason Scott. Students:
Mike Schuh, and
Karthik Pillai Ganesan (Computer Science), Alexander Engell (Physics), Ricky Egeland (Physics),
The Solar Dynamics Observatory (SDO) feature finding team is a large international consortium tasked by NASA to produce a comprehensive system for automated feature recognition for SDO. We are producing robust and very efficient software modules that can keep up with the SDO data stream and detect, trace, and analyze a large number of phenomena, including flares, sigmoids, filaments, and coronal dimmings.
Main publication: “Computer Vision for the Solar Dynamics Observatory” (Invited Paper), P.C.H. Martens, G.D.R. Attrill, A.R. Davey, A. Engell, S. Farid, P.C. Grigis, J. Kasper, K. Korreck, S.H. Saar, A. Savcheva, Y. Su, P. Testa, M. Wills-Davey, P.N. Bernasconi, N.-E. Raouafi, V.A. Delouille, J.F. Hochedez, J.W. Cirtain, C.E. DeForest, R.A. Angryk, I. De Moortel, T. Wiegelmann, M.K. Georgoulis, R.T.J. McAteer, R.P. Timmons 2012, Solar Phys., SDO Mission Issue, 275, 79-113.
2. Dynamo Modeling for the Sun and Solar-type Stars
We use a new and innovative stellar dynamo simulation code, developed by former graduate student Andrés Muñoz, to explore the origins of, and decipher the evolution of solar magnetic activity over multiple time scales ranging from centuries to stellar and planetary evolutionary time scales. The results from that dynamo code are as input for a surface magnetic flux transport code developed by our collaborators at the University of St. Andrews in Scotland to produce accurate predictions for the Sun’s surface magnetic fields and open magnetic flux. The former regulates the variations in the total solar irradiance and the latter the amount of Cosmic Rays that penetrate the atmosphere of the Earth, both of which are key physical agents of the solar influence on the Earth’s climate.
The most recent, and exciting, result is a clear explanation for the unusual length and depth of the most recent solar minimum,
“The Unusual Minimum of Sunspot Cycle 23 a Consequence of Meridional Plasma Flow Variations”,
Dibyendu Nandy, Andres Munoz-Jaramillo, and Petrus C. H. Martens 2011, Nature 471, 80-82.
Personnel involved: Piet Martens,
Dibyendu Nandi (Iiserkol, India),
Anthony Yeates (Univ. of Durham), Duncan Mackay (St Andrews),
Andrés Muñoz (Jack Eddy postdoc at Harvard-Smithsonian). Graduate Student: Ernest Amouzou (Physics)
3. The Faint Young Sun Paradox
The geological and biological record support that the Earths biosphere was considerably warmer than currently during the origin of life on Earth and for several billions of years thereafter. Yet, stellar evolution calculations support the Sun reaching the Zero Age Mean Sequence at about 75% of its present luminosity, and linearly increasing in time up to its current level. Climate models predict a Snowball Earth for such a low solar constant. That is the paradox: Solving this puzzle is our objective.
One recent presentation:
“The Faint Young Sun Paradox”, (Invited Public Lecture), P.C.H. Martens, International Symposium
on Solar-Terrestrial Physics, November 6-9, 2012, Indian Institute of Science, Education and Research, Pune, India.
Personnel Involved: Piet Martens
Contributers: Jeremy Drake, Steve Saar, Leon Golub, Steven Cramner, and Andres Munoz (all CfA),
and John Priscu (MSU)
Students: Ricky Egeland (Physics)
4. The Virtual Solar Observatory
The Virtual Solar Observatory (VSO) has been developed to allow researchers, educators, and the general public to access data and images from the major sources of on-line solar data. The VSO substantially reduces the effort required to locate disparate data sets, and removes the need for the user to locate the data and learn multiple interfaces. The VSO provides a single interface to more than 60 geographically distributed data sets including space- and ground-based sources. These data sets incorporate several physical variables including magnetic field, intensity, Doppler velocity, etc., and all wavelengths from X-ray to radio. All layers of the Sun, from the interior to the corona, are included. In the linked paper we describe the system and present the interface that the user will encounter. Future enhancements are planned for the system, and student participation is encouraged.
Main publication: “The Virtual Solar Observatory — A Resource for International Heliophysics Research” (Invited Contribution),
Frank Hill, Piet Martens, Keiji Yosimura, Joseph Gurman, Joseph Hourcle, George Dimitoglou, Igor Suarez-Sola, Steve Wampler, Kevin Reardon, Alisdair Davey, Richard S. Bogart, and Karin Q. Tian,
in: “Proceedings of the UN/ESA/NASA/Japan Workshop”, 2009, eds. Guenter Eichhorn and Hans Haubold, Earth, Moon, and Planets 104(10), 315-330.
Personnel involved: Piet Martens and
Keiji Yosimura at MSU, list of authors above
Founders of the VSO (1999) are: Frank Hill (NSO),
Joe Gurman (NASA-Goddard),
Rick Bogart (Stanford), and Piet Martens (MSU)
Students: Students (Physics and Computer Science) are welcome for research credit.
5. Diagnostics and Modeling of Steady and Flaring Solar Coronal Loops
The building blocks of X-ray and EUV emission in the solar corona are so-called coronal loops. These loops, it is believed, follow the magnetic field lines and they are brighter than the surrounding corona because coronal heating — the conversion of free magnetic to thermal energy — is concentrated inside them. Solar coronal loops are now being observed with unprecedented spatial, spectral and temporal resolution by the AIA instrument on the Solar Dynamics Observatory. We have developed analytical models for quasi-static solar coronal loops, an advanced numerical code for simulating the thermal structure and dynamics of steady and flaring loops, and sophisticated techniques for analyzing the observations of such loops. Diagnosis and modeling of loops is an ongoing effort involving several students.
“Outflow and Dark Bands at Arcade-like Active Region Boundaries”, J.T. Scott, P. C. H. Martens,
and L. Tarr 2013, Astrophys. J. 765: 82 (14 pp.).
“Fast Differential Emission Measure Inversion of Solar Coronal Data”,
Joseph Plowman, Charles Kankelborg, and Petrus Martens 2013,
Astrophys. J., 771: 2 (13 pp.).
“The Solar Corona: What Are The Remaining Fundamental Physical Questions?”
(Invited Review), Petrus C. Martens, in: Proceedings of the International
Symposium on Solar-Terrestrial Physics, November 2012, Pune, India,
Bull. Astron. Soc. India, in press.
- I have taught the advanced graduate course PHYS 580, “Hydrodynamics
and Magnetohydrodynamics”, alone and together with other members of the MSU solar
group. In 2007 we alternated teaching the subjects listed in the
I also enjoy teaching the University Seminar (
CLS 101), a broad literature based course for freshmen. In the past I have taught
courses in Astronomy and Physics at
Harvard University , Stanford University, the
University of Buenos Aires, and
Embry-Riddle Aeronautical University.
Jonathan Cirtain (2005), my first graduate student, very recently won a 2011
Presidential Early Career Award (see the White House
press release), an exceptional achievement. Previously Jonathan also won the
2007 “Young Scientist Award” of the
International Association of Geomagnetism and Aeronomy/International
Union of Geodesy and Geophysics. Jonathan now heads the
Physics Group at NASA Marshall Space Flight Center. He is NASA
Project Scientist for the Hinode
mission, and Principal Investigator for
a number of NASA rocket experiments that test new innovative space
Henry (Trae) Winter
defended his thesis on November 4th 2008 (Election day), and won his election to PhD as well.
Trae is now an Astrophysicist in the
Solar and Stellar X-ray Group of the
Harvard-Smithsonian Center for Astrophysics.
At the 2005 AGU meeting in New Orleans, Trae won “Outstanding Student Paper Award” twice,
one for a research paper and another one for an educational paper. Trae and I continue to
collaborate on simulations and analysis of EUV and X-ray coronal loops.
Andrés Muñoz, jointly mentored
Nandi and myself, defended his thesis in June 2010. He did exceptionally well, authoring
three first author ApJ papers for this thesis, and co-authoring a paper in Nature (see my
list of joint publications with students). Andrés now has
joined Trae as a Jack Eddy
postdoctoral fellow in the
Solar and Stellar X-ray Group of the
Harvard-Smithsonian Center for Astrophysics.
Andrés’ just published a paper on his work in the Spanish language version of Scientific American,
and, most impressively, he recently won the 2011
Fred L. Scarf Award
from the Space Physics and
Aeronomy Section of the American Geophysical Union, for the best thesis in North-America in
this field. Andrés will receive the award and present an invited talk at the 2011 Fall AGU in San
Jason Scott defended his
thesis with success in November 2011. The thesis includes three first author papers, plus a fourth
one in draft form. Jason graduated from MSU in December 2004 and won the “2005 Dean’s
Award for Excellence as the Outstanding Graduating Senior in Sciences”.
Both he and Jonathan Cirtain also won NASA
Graduate Student Research Program fellowships to support their graduate studies.
Jason’s research concentrates on the EUV and X-ray emission of solar coronal loops, using images
and spectra from TRACE, Hinode, and SDO.
Current Graduate Students
started working with me in January of 2010. He is doing research on the solar dynamo.
Alexander Engell became a graduate student at MSU in the fall of 2011. He is interested in magnetic fields,
feature recognition, and Solar Energetic Particles (SEPs).
Ricky Egeland started working with me in the fall of 2012, after starting his graduate studies in the fall of 2011. He is interested in the field of the Solar-Stellar connection, collaborating with Phil Judge at HAO.
I was the original PI of our NSF supported
Research Opportunities for
Undergraduates program, ten weeks of solar research during the summer.
I also started up the
Solar Physics REU program at the Harvard-Smithsonian Center for Astrophysics in
2008. In the summer of 2011 I worked with REU students
(St Andrews) and
Rahul Sharma (Udaipur). Their joint final presentation is
here. In 2012 Dibyendu Nandi and I worked with Sushant Mahajan on the development of a
code for solar surface magnetic flux transport simulations, see
In previous years I have worked with
Kudzanayi Munetsi-Mugomba from
determining the accuracy and stability of analytical solutions for the
temperature structure in coronal loops. Before that
Antonia Wilmot-Smith, from
St. Andrews University in Scotland worked with
Dibyendu Nandi and me
on a project to simulate solar and stellar cycles through sets of nonlinear
ordinary differential equations, while in the summer of 2003 Dibyendu and I
Andrés Muñoz from the
Universidad de los Andes in Colombia on a project to simulate stellar dynamo cycles.
Another succesful project
within this program was with Paul Wood from St. Andrews in the summer of
2000. At Harvard-Smithsonian, in 2009, I supervised St Andrews REU student Jonathan Constable, jointly with Anthony Yeates, which also led to a joint publication.
Space Exploration: Solar Physics Missions
- Prepatory science studies
- Instrument development and testing
- Science operations
- Data analysis
- Theoretical studies an simulations prompted by new space observations
- Production and distribution of
Public Outreach materials.
MSU Solar Physics group continues its involvement in space science missions
during the first decade of this century.
MSU students, from undergraduates to postdocs, are actively involved in all phases of our
missions, such as:
Missions I am and have been involved with:
Atmospheric Imaging Assembly (AIA): We are partners with the
Lockheed-Martin Solar & Astrophysics Lab
and the Harvard-Smithsonian
Center for Astrophysics to build an assembly of six EUV telescopes to fly on NASA’s
Solar Dynamics Observatory. SDO was launched
in February 2010, and the mission is designed to last until 2020.
Prof. David McKenzie
and myself are the MSU Co-I’s. MSU plays a significant role in AIA’s design and
calibration, science & data analysis, and the Education & Public Outreach program.
launched on September 23, 2006. The MSU group is deeply involved with the
XRT mission operations and
data analysis. Jason Scott is analyzing coronal loop emission as seen by EIS and
XRT. MSU Lead for
this mission is Prof.
was launched on February 5, 2002.
My student former Trae Winter simulates solar flares to see whether agreement can
be reached with RHESSI’s observations of flare X-ray emissions. MSU Lead for
this mission is Prof.
I contributed to the TRACE proposal, fostered and coordinated joint
science operations between TRACE and SOHO, and currently oversee the MSU
part of TRACE Mission Operations and Data Analysis. Our former graduate
Cirtain completed his thesis on data from this instrument combined
with CDS on SoHO.
MOSES: I am a science Co-I on MSU’s (Prof. Charles
Kankelborg, PI) Multi-Order Slitless EUV Spectrograph (MOSES).
- Yohkoh-SXT: At
Lockheed (1990-1993) I participated in the
development, performance verification, science operations, and data analysis.
I co-chaired the organization of the 2002 Yohkoh 10th Anniversary meeting, and I edited the
Due to an unfortunate accident ground controllers lost contact with
the spacecraft in December 2001, and the mission has now ended.
As SOHO Science Operations Coordinator (1993-1998) I took part in the
testing and integration of the experiments and ground system, planned and supervised the in-orbit
commissioning of the spacecraft and experiments, chaired the SOHO Science Planning Working Group,
responsible for the implementation of SOHO Science Program, and coordinated joint observations
between the SOHO experiments, Ground Based Solar Observatories world-wide, and other spacecraft,
such as Yohkoh, TRACE, and Ulysses.
- NIXT & SMM: In the 1980’s I was involved Normal Incidence X-ray
Telescope project, while at the
Harvard-Smithsonian Center for Astrophysics (1987-1990), and analyzed data from the
Dutch Hard X-ray Imaging Spectrometer onboard the Solar Maximum Mission, while at Utrecht
- See NASA’s Office of Space Science Web Page for a full listing of
past and current missions, and mission opportunities