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Katherine Whitaker - University of Massachusetts Amherst. Amherst, MA, US

Katherine Whitaker

Associate Professor of Astronomy | University of Massachusetts Amherst


Kate Whitaker is an observational extragalactic astronomer who studies galaxy formation and evolution at the very edges of the universe.

Expertise (3)

Detection of Dead Galaxies

Galaxy formation and evolution



Kate Whitaker is an observational extragalactic astronomer who studies galaxy formation and evolution over the past twelve billion years of cosmic time.

Working with the Cosmic Dawn Center in Copenhagen, Denmark, Whitaker and her team are working towards pushing our detection of quiescent “red and dead” galaxies even earlier in time (within a billion years of the Big Bang itself!) with a goal understand the detailed physics of the structures and underlying stellar populations of these early massive galaxies.

In 2019, Whitaker gained international attention for her work on a team that discovered a new monster galaxy hiding behind a cloud of stardust.

Social Media






UMass New Galaxy Discovery | Connecting Point | Nov. 20, 2019 UMass Team Discovers New 'Monster' Galaxy A Requiem for Massive Galaxies with Kate Whitaker


Education (4)

Yale University: Ph.D., Astronomy

Yale University: M.Phil., Astronomy

Yale University: M.Sc., Astronomy

UMass Amherst: B.S., Physics and Astronom

Select Media Coverage (5)

New image from Webb Telescope, processed by UMass astronomers, reveals the deepest parts of space in Pandora’s Cluster

The Boston Globe  online


“These galaxies are some of the very first galaxies in the universe,” Katherine Whitaker, an assistant professor of astronomy at UMass Amherst, said in a phone interview. “Webb is like a time machine.”

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UMass Amherst astronomers help uncover new details deep in space

WWLP  online


“With these pictures, we’re looking back in time, 97% of the way to the Big Bang,” says Kate Whitaker, professor of astronomy at UMass Amherst. “The James Webb Space Telescope is fundamentally changing our understanding of our cosmic origins.”

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Most distant star ever seen found in Hubble Space Telescope image

National Geographic  


Scientists estimate that Earendel is at least 50 times more massive than the sun, although it may be a binary pair of stars rather than a lone star. Follow-up observations with NASA’s James Webb Space Telescope (JWST) should help confirm whether the object is a star—or something else entirely. “This is a really exciting interpretation, and I’d love for it to be true,” says astronomer Katherine Whitaker of the University of Massachusetts Amherst, who was not part of the discovery team. “These are the types of things I hope we discover more of, and I look forward to what their follow-up observations show.”

hubble space telescope

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Hubble telescope finds dead galaxies. Scientists say they may help us understand 'where we're from'

USA Today  


If Kate Whitaker had to explain her latest scientific discovery and why it's a big deal to her three children — 4, 8, and 10 — the astronomy professor at the University of Massachusetts, Amherst would try something like this: “Earth is a planet and our planet goes around the sun once a year; our sun is a star, and it’s one of billions of stars in our galaxy,’” Whitaker said. “Our galaxy is one of billions or trillions of galaxies in the universe and mommy is trying to understand how these galaxies formed and evolved and change — just like how you formed and grow. So I’m using a telescope, which is like a time machine, to study that.”

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Hubble Finds Early, Massive Galaxies Running on Empty

Hubble Space Telescope  online


"At this point in our universe, all galaxies should be forming lots of stars. It's the peak epoch of star formation," explained lead author Kate Whitaker, assistant professor of astronomy at the University of Massachusetts, Amherst. Whitaker is also associate faculty at the Cosmic Dawn Center in Copenhagen, Denmark. "So what happened to all the cold gas in these galaxies so early on?"

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Select Publications (5)

The JWST FRESCO survey: legacy NIRCam/grism spectroscopy and imaging in the two GOODS fields

Monthly Notices of the Royal Astronomical Society

2023 We present the JWST cycle 1 53.8 h medium program FRESCO, short for ‘First Reionization Epoch Spectroscopically Complete Observations’. FRESCO covers 62 arcmin2 in each of the two GOODS/CANDELS fields for a total area of 124 arcmin2 exploiting JWST’s powerful new grism spectroscopic capabilities at near-infrared wavelengths. By obtaining ∼2 h deep NIRCam/grism observations with the F444W filter, FRESCO yields unprecedented spectra at R ∼ 1600 covering 3.8–5.0 µm for most galaxies in the NIRCam field of view.

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Dust attenuation, dust content, and geometry of star-forming galaxies

Monthly Notices of the Royal Astronomical Society

2023 We analyse the joint distribution of dust attenuation and projected axis ratios, together with galaxy size and surface brightness profile information, to infer lessons on the dust content and star/dust geometry within star-forming galaxies at 0 < z < 2.5. To do so, we make use of large observational data sets from KiDS + VIKING + HSC-SSP and extend the analysis out to redshift z = 2.5 using the HST surveys CANDELS and 3D-DASH. We construct suites of SKIRT radiative transfer models for idealized galaxies observed under random viewing angles with the aim of reproducing the aforementioned distributions, including the level and inclination dependence of dust attenuation.

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As Simple as Possible but No Simpler: Optimizing the Performance of Neural Net Emulators for Galaxy SED Fitting

The Astrophysical Journal

2023 IOP Publishing Description Artificial neural network emulators have been demonstrated to be a very computationally efficient method to rapidly generate galaxy spectral energy distributions, for parameter inference or otherwise. Using a highly flexible and fast mathematical structure, they can learn the nontrivial relationship between input galaxy parameters and output observables. However, they do so imperfectly, and small errors in flux prediction can yield large differences in recovered parameters. In this work, we investigate the relationship between an emulator's execution time, uncertainties, correlated errors, and ability to recover accurate posteriors.

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UNCOVERing the extended strong lensing structures of Abell 2744 with the deepest JWST imaging

Monthly Notices of the Royal Astronomical Society

2023 We present a new parametric lens model for the massive galaxy cluster Abell 2744 based on new ultra-deep JWST imaging taken in the framework of the UNCOVER program. These observations constitute the deepest JWST images of a lensing cluster to date, adding to existing deep Hubble Space Telescope (HST) images and the recent JWST Early Release Science and Director’s Discretionary Time data taken for this field. The wide field of view of UNCOVER (∼45 arcmin2) extends beyond the cluster’s well-studied central core and reveals a spectacular wealth of prominent lensed features around two massive cluster sub-structures in the north and north-west, where no multiple images were previously known.

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JWST UNCOVER: Extremely Red and Compact Object at z phot≃ 7.6 Triply Imaged by A2744

The Astrophysical Journal

2023 Recent JWST/NIRCam imaging taken for the ultra-deep UNCOVER program reveals a very red dropout object at z phot≃ 7.6, triply imaged by the galaxy cluster A2744 (z d= 0.308). All three images are very compact, ie, unresolved, with a delensed size upper limit of r e≲ 35 pc. The images have apparent magnitudes of m F444W∼ 25− 26 AB, and the magnification-corrected absolute UV magnitude of the source is M UV, 1450=− 16.81±0.09. From the sum of observed fluxes and from a spectral energy distribution (SED) analysis, we obtain estimates of the bolometric luminosities of the source of L bol≳ 10 43 erg s− 1 and L bol∼ 10 44–10 46 erg s− 1, respectively.

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