Saurabh W. Jha

photo credit: Miguel Acevedo, RutgersDistingushed Professor
Department of Physics and Astronomy
Rutgers, the State University of New Jersey
136 Frelinghuysen Rd, Piscataway, NJ 08854

office: Serin 315, Busch campus
tel: (848) 445-8962
fax: (732) 445-4343


I joined the Rutgers astrophysics group in September 2007. Previously, I was a Panofsky Fellow at the Kavli Institute for Particle Astrophysics and Cosmology at the Stanford Linear Accelerator Center, a Miller Fellow in the University of California, Berkeley Department of Astronomy, and a graduate student at the Harvard-Smithsonian Center for Astrophysics.

curriculum vitae (pdf)
publications (pdf) (ADS) (ADS: articles only) (ADS: refereed only)
(ORCid) (Google Scholar)

Research interests and collaborations


My main research focus is the observational study of Type Ia supernovae (SN Ia). I am interested in understanding the properties of these exploding white dwarf stars: their progenitor systems, how they explode, and using this knowledge to turn them into tools with which to survey the Universe.

This work is done in collaboration with a variety of groups:

The High-z Supernova Search Team first published strong evidence from observations of distant SN Ia that we live in an accelerating Universe. Along with the results of the Supernova Cosmology Project, this work was called the Breakthrough of the Year by Science in 1998, and was awarded the 2007 Gruber Cosmology Prize, the 2015 Breakthrough Prize in Fundamental Physics, and the 2011 Nobel Prize in Physics.

Soon the Vera Rubin Observatory and its Legacy Survey of Space and Time (LSST) will find many thousands of SN Ia. This huge number of objects means we will need new methods to make best use of the data. I am a member of the Rubin Transients & Variable Stars Science Collaboration and have Builder Status in the Rubin Dark Energy Science Collaboration (DESC) where I was the co-convener of the Supernova Working Group as well as the Observing Strategy Working Group. I was also a DESC Ombudsperson and now serve on the Rubin Survey Cadence Optimization Committee. The highest quality data for distant supernovae will come from space and I am part of a supernova Science Investigation Team for the Nancy Grace Roman Space Telescope and I am a member of the Roman Science Interest Group.

While distant SN Ia have driven our understanding of the history of the expansion of the Universe, nearby SN Ia are the crucial underpinning to this enterprise. Not only do they anchor the Hubble diagram for cosmology, they provide the samples which show the utility of SN Ia as distance indicators, and give constraints on the Hubble constant. They are also the ones which we can study the best, from observations at many wavelengths to data at late times when more distant objects are too faint to be measured. We recently worked on the Foundation Supernova Survey using the Pan-STARRS PS1 telescope to observe and follow-up nearby supernovae, including spectroscopic analysis by former graduate student Kyle Dettman. Current graduate student Conor Larison has shown that SN Ia in nearby clusters of galaxies have different light curve properties than would be expected based on their host galaxies alone.    

I am leading the SIRAH program, using the Hubble Space Telescope in Cycles 27 and 28, along with Gemini and many other ground-based observatories to observe Hubble-flow SN Ia in the near-infrared, where they are nearly standard (rather than standardizable) candles.

We are also trying to understand the progenitors and explosion mechanism for SN Ia. In particular, we are interested in studying objects that are "peculiar cousins" to normal SN Ia, like the recently identified class of type Iax supernovae, named after the prototype SN 2002cx. Our recent work, led by former graduate student Curtis McCully, suggests these are thermonuclear explosions of white dwarfs that do not completely unbind the star. A most exciting development is our discovery of the progenitor system of the type Iax SN 2012Z with the Hubble Space Telescope; this is the first time that a progenitor system for a white dwarf supernova has ever been seen in pre-explosion images. Graduate student Yssavo Camacho-Neves led a spectroscopic analysis of SN 2014dt in M61, one of the nearest type-Iax SN known.

Graduate student Lindsey Kwok is leading our effort to study the astrophysics of white dwarf supernovae with JWST near-infrared and mid-infrared spectroscopic observations at late times, where we can "see through" the supernova ejecta.

As part of the CANDELS and CLASH Multi-Cycle Treasury Programs on the Hubble Space Telescope, and the Frontier Fields and RELICS programs, we are searching for SN Ia beyond redshifts z > 1.5 using the WFC3/IR instrument. We have also found and analyzed three gravitationally lensed supernovae behind CLASH galaxy clusters in a project led by former graduate student Brandon Patel, and have continued studying other lensed supernovae.

The ESSENCE project followed up earlier high-redshift SN Ia work, in an attempt to characterize the dark energy that is driving the accelerating expansion of the Universe, by measuring its equation of state to 10% accuracy. The SDSS-II Supernova Survey filled a gap by finding and analyzing hundreds of SN Ia in the redshift range between z=0.1 and z=0.3.

MLCS2k2 was the development of the multi-color light curve shape method to turn SN Ia optical light curves into precise distances. This analysis tool continues to grow and be refined, and is in use by many SN Ia projects. The CfA II sample of SN Ia, presented in my doctoral thesis, comprises 44 objects homogeneously observed and analyzed, including the largest collection of near-ultraviolet U-band light curves published at the time.

Extrasolar planets

I am also interested in the detection and characterization of planets around other stars. With the AFOE group, we discovered the planetary companion to rho Coronae Borealis in 1997. In addition, colleagues and I have shown that a few of the transiting companions discovered by the OGLE survey are planets, including OGLE-TR-56b (the first planet discovered first by its transit), OGLE-TR-113b, and OGLE-TR-10b.


Rutgers is a partner in the Southern African Large Telescope. SALT is one of the world's largest optical telescopes and I have been using it in many facets of my research to observe supernovae near and far. In the past, I chaired the SALT Science Committee.


Byrne Seminar: Death from the Skies? (spring 2013)

Physics 106: Concepts in Physics (spring 2013, 2014)

Physics 110: Astronomy & Cosmology (fall 2011, 2012, 2013; spring 2016; fall 2017, 2018, 2019)

Physics 341: Principles of Astrophysics (fall 2008, 2009, 2010, 2020)

Physics 342: Principles of Astrophysics (spring 2009, 2010, 2011, 2017)

Physics 441/541: Stars (spring 2018, 2020, 2022)

Physics 514: Radiative Processes (spring 2014, 2015, 2016, 2021, 2022, 2023)

Physics 690: Special Topics in Astrophysics: The Dark Universe (spring 2008)

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