Extraordinary Black Hole

A Different Kind of Black Hole

Astronomers discovered a black hole unlike any other. At one hundred thousand solar masses, it is smaller than the black holes we have found at the centers of galaxies but bigger than the black holes that are born when stars explode. This makes it one of the only confirmed intermediate-mass black holes, an object that has long been sought by astronomers.

Anil Seth

“We have very good detections of the biggest, stellar-mass black holes up to 100 times the size of our sun, and supermassive black holes at the centers of galaxies that are millions of times the size of our sun, but there aren’t any measurements of black between these. That’s a large gap,” said senior author Anil Seth, associate professor of astronomy at the University of Utah and co-author of the study. “This discovery fills the gap.”

The black hole was hidden within B023-G078, an enormous star cluster in our closest neighboring galaxy Andromeda. Long thought to be a globular star cluster, the researchers argue that B023-G078 is instead a stripped nucleus. Stripped nuclei are remnants of small galaxies that fell into bigger ones and had their outer stars stripped away by gravitational forces. What’s left behind is a tiny, dense nucleus orbiting the bigger galaxy and at the center of that nucleus, a black hole.

“Previously, we’ve found big black holes within massive, stripped nuclei that are much bigger than B023-G078. We knew that there must be smaller black holes in lower mass stripped nuclei, but there’s never been direct evidence,” said lead author Renuka Pechetti of Liverpool John Moores University, who started the research while at the U. “I think this is a pretty clear case that we have finally found one of these objects.”

The study published on Jan. 11, 2022, in The Astrophysical Journal.

A decades-long hunch

B023-G078 was known as a massive globular star cluster—a spherical collection of stars bound tightly by gravity. However, there had only been a single observation of the object that determined its overall mass, about 6.2 million solar masses. For years, Seth had a feeling it was something else.

“I knew that the B023-G078 object was one of the most massive objects in Andromeda and thought it could be a candidate for a stripped nucleus. But we needed data to prove it. We’d been applying to various telescopes to get more observations for many, many years and my proposals always failed,” said Seth. “When we discovered a supermassive black hole within a stripped nucleus in 2014, the Gemini Observatory gave us the chance to explore the idea.”

A wide-field image of M31 with the red box and inset showing the location and image of B023-G78 where the black hole was found.

With their new observational data from the Gemini Observatory and images from the Hubble Space Telescope, Pechetti, Seth and their team calculated how mass was distributed within the object by modeling its light profile. A globular cluster has a signature light profile that has the same shape near the center as it does in the outer regions. B023-G078 is different. The light at the center is round and then gets flatter moving outwards. The chemical makeup of the stars changes too, with more heavy elements in the stars at the center than those near the object’s edge.

“Globular star clusters basically form at the same time. In contrast, these stripped nuclei can have repeated formation episodes, where gas falls into the center of the galaxy, and forms stars. And other star clusters can get dragged into the center by the gravitational forces of the galaxy,” said Seth. “It’s kind of the dumping ground for a bunch of different stuff. So, stars in stripped nuclei will be more complicated than in globular clusters. And that’s what we saw in B023-G078.”

The researchers used the object’s mass distribution to predict how fast the stars should be moving at any given location within the cluster and compared it to their data. The highest velocity stars were orbiting around the center. When they built a model without including a black hole, the stars at the center were too slow compared their observations. When they added the black hole, they got speeds that matched the data. The black hole adds to the evidence that this object is a stripped nucleus.

“The stellar velocities we are getting gives us direct evidence that there’s some kind of dark mass right at the center,” said Pechetti. “It’s very hard for globular clusters to form big black holes. But if it’s in a stripped nucleus, then there must already be a black hole present, left as a remnant from the smaller galaxy that fell into the bigger one.”

The researchers are hoping to observe more stripped nuclei that may hold more intermediate-mass black holes. These are an opportunity to learn more about the black hole population at the centers of low-mass galaxies, and to learn about how galaxies are built up from smaller building blocks.

“We know big galaxies form generally from the merging of smaller galaxies, but these stripped nuclei allow us to decipher the details of those past interactions,” said Seth.

Other authors include Sebastian Kamann of the Liverpool John Moores University; Nelson Caldwell, Harvard-Smithsonian Center for Astrophysics; Jay Strader, Michigan State University; Mark den Brok, Leibniz-Institut für Astrophysik Potsdam; Nora Luetzgendorf, European Space Agency; Nadine Neumayer, Max Planck Institüt für Astronomie; and Karina Voggel, Observatoire astronomique de Strasbourg.

- by Lisa Potter, published in @theU and the Deseret News


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Of Mice and Monarchs

Of Mice and Monarchs

Sara Weinstein, Postdoctoral Researcher

Monarch butterflies possess a potent chemical armor. As caterpillars, they eat plants filled with toxic cardenolides that build up in their bodies and make them unpalatable to most—but not all—predators. In central Mexico, where the largest winter monarch aggregations occur, scientists observed that rodents attack monarchs that fall to the ground. In particular, the black-eared mouse (Peromyscus melanotis) specializes in these bitter-tasting insects, eating as many as 40 per night.

In a new study, University of Utah biologists found that mice at California monarch overwintering sites can also consume monarch butterflies. Working at one of the largest monarch aggregations outside of Mexico, Pismo State Beach Monarch Butterfly Grove, the researchers discovered that the western harvest mouse (Reithrodontomys megalotis) also ate the grounded monarchs. However, with the precipitous decline in western monarch populations, this butterfly buffet may be in jeopardy.

A harvest mouse munching on a monarch.

The authors do not think that rodents are contributing to the western monarch decline, nor that the monarchs are the only thing that mice can eat. Rather, documenting this new feeding behavior is a reminder of how little we know about the interactions that may be lost as insect populations decline.

“We are in an insect apocalypse right now. There are estimates that 40% of studied invertebrate species are threatened and that over 70% of flying insect biomass is already gone. This is devastating on its own and is also going to have enormous impacts on the other organisms that feed on insects,” said Sara Weinstein, the postdoctoral researcher who led the study.

“Western monarchs and other western butterflies need conservation attention and part of that awareness-raising is illuminating the many ways these animals are interconnected to other insects, birds, mammals, as well as our human communities. This study helps us appreciate more deeply how fewer butterflies means less food for other native animals” said Emma Pelton, senior conservation biologist at the Xerces Society.

Weinstein with a lab-reared monarch.

The study published in the journal Ecology on Dec. 12, 2021.

To study mouse-monarch interactions, the researchers first trapped rodents in the grove in February 2020. The rodents were released, but their feces were kept to screen for monarch DNA—which they found in one sample. This first survey occurred in late winter as monarchs were leaving the aggregation and few remained for mice to munch. Weinstein and colleagues intended to return the following fall during peak monarch season. However, after years of decline, the western monarch population crashed.

“At a site where 100,000 butterflies used to roost, in 2020 there where were fewer than 200 monarchs. So, we had to change tactics,” Weinstein said. “We tested whether rodents would feed on the butterflies using captive-reared monarchs.”

Weinstein set up lab-reared monarch carcasses under camera traps and captured footage of wild harvest mice eating butterflies. She also caught a half dozen mice and offered them monarchs. The mice ate monarchs, typically favoring the abdomen or thorax, high-calorie parts with fewer toxins.

“Many rodent species are likely to have some resistance to cardenolides in monarchs, due to genetic changes at the site where these toxins bind,” said Weinstein. “The Pismo Grove is one of hundreds of western monarch aggregation sites, and it seems likely that, at least in the past, rodents throughout the western monarch range may have supplemented their winter diets with monarchs. If you can handle the cardenolides in a monarch, their bodies are full of fat and offer a pretty good meal.”

Animation of mouse eating a butterfly.

Mouse eating an entire monarch butterfly.

This meal will be a lot harder to find, as over 90% of western monarchs have disappeared in the last 40 years. The missing beauties will surely impact the ecosystem that depends on them for food.

Denise Dearing, Distinguished Professor at the U, was senior author of the study. Photos and animations by Sara Weinstein.

Find the study, “Harvest mice (Reithrodontomys megalotis) consume monarch butterflies (Danaus plexippus), in the journal Ecology: https://doi.org/10.1002/ecy.3607


by Lisa Potter, first published in @theU


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Safety Commitee

Safety Committee

The College has an established safety committee consisting of the Dean or their representative, Chairs of each departmental safety committee or departmental nominee, and the Associate Director of Safety for the College. This committee is charged with communicating and ensuring compliance with University requirements and directives, serving as a resource to faculty, staff, and students, and developing plans and initiatives to meet requirements while promoting a culture of safety.

The committee has identified objectives to improve safety across the College during the 2020 and 2021 Academic years. Progress toward the objectives is measured through planning, discussion, and reports at committee meetings. Ideas for areas of improvement can be communicated through departmental safety committees or directly to a college safety committee member.

Current members

David Carrier

School of Biological Sciences

Charlie Jui

Physics and Astronomy

David Thomas

Manager of Educational Laboratory Facilities at the Crocker Science Center

Peter Trapa

Dean, College of Science

Aaron Fogelson


Ryan Looper


Jim Muller

Executive Director of Facilities Management

Sarah Morris-Benavides

College of Science/EHS

Committee Resources


James Webb Space Telescope

James Webb Space Telescope

In December 2020 the James Webb Space Telescope (JWST) finally launched. The $10 billion observatory is a twenty-year joint effort of NASA, the European Space Agency, and the Canadian Space Agency, and the most powerful telescope ever developed. Its mission—peer 13.5 billion lightyears back in time to the earliest stages of the universe.

Anil Seth

JWST’s launch date was December 25 from Europe’s Spaceport in Kourou, French Guiana. Longtime fans of the telescope are celebrating it as a Christmas miracle. It was the first planned to launch in 2007, but decades of delays and false hope drove the project from its initial budget of $500 million up to its current $10 billion cost.

You can watch recorded launch video and future NASA livestreams at  https://www.nasa.gov/nasalive.

The stakes are high for Anil Seth, associate professor in the Department of Physics & Astronomy. Out of more than 1,000 proposals for observation time on the telescope, Seth’s is one of 266 that were approved. He spoke with AtTheU to talk about this cosmic milestone.

What is the James Webb Space Telescope?

It is the largest and most powerful telescope that we’ve ever sent into space—the primary mirror is about the size of a typical house. It’s really big compared to the Hubble Space Telescope, which has a primary mirror the size of a bedroom. Hubble uses the ultraviolet and visible light to create jaw-dropping images of deep space that fundamentally changed our understanding of the cosmos. JWST will be much, much, much farther away than Hubble, located almost one million miles from Earth. From there, it can detect the faintest traces of infrared light, the wavelength of light emitted by everything that produces heat.

NASA assembly, July 2017

The telescope’s primary power is to detect faint galaxies far, far away. It’ll be able to pick up the infrared light spectrum of planets, newly forming stars, black holes, and other faint objects in ways that we’ve never been able to before. Almost every astronomer is probably going to want to use JWST for something. We saw so much using the Hubble Space Telescope. With JWST, we’ll be able to see more than we can imagine. It’s very exciting.

The launch date has been pushed back several times including once this week. Is the telescope launch tricker then usual?

The size makes it really hard to launch. The telescope has three big segments—a sunshield the size of a tennis court, the house-sized primary mirror, and the secondary mirror, Right now, it’s all packaged up like a Christmas present to fit inside the rocket. After launch, the segments will begin to unfold. It’s a complicated process involving hundreds of steps that have to work perfectly. This has never been done before—one error and the whole project could fail. That’s why people are so stressed out!

Where will JWST orbit in space?

It’s going to orbit the sun almost one million miles away from Earth. It will live at what is called a Lagrange point, a location where gravity from the earth and sun are equal. And will just sit there, orbiting with the Earth around the sun. This ensures that the telescope will always point away from the sun.

Full-scale model, September 2005

Anything warm emits infrared light—stars, humans, every other thing on Earth. To make an infrared-detecting telescope, the equipment needs to be extremely cold, so its heat doesn’t interfere with infrared readings from space. That’s what the sun shield is for. The massive mylar sail will create a shadow that prevents the telescope from absorbing heat. The sunshade will begin to unfurl a week after launch, starting with 107 release mechanisms that have to fire simultaneously. The sun shield will then always be between the telescope and sun, keeping the telescope really cold. If this doesn’t happen right…it’ll be bad.

JWST’s location also provides a wide-open view for observations. The Hubble space telescope orbits the Earth just over 300 miles up, which means the planet sometimes blocks the telescope’s vision as it orbits the earth every 90 minutes. At JWST’s Lagrange position, it’s much easier to keep a single orientation in the sky for a longer time and to make observations constantly. So we’ll end up getting more data each year from JWST than from Hubble.

You will be one of the first astronomers to get observation time on the JWST. Can you tell us about your research?

I study black holes. Every black hole has stuff falling onto it that emits light. It turns out that a lot of that light gets emitted at infrared wavelengths. This telescope is much, much, more sensitive to those wavelengths than any other previous telescope. The problem is that we’ve never seen what a faint black hole looks like at these wavelengths.

The Andromeda Galaxy, approximately 2.5 million light-years from Earth.

I’m leading a project that will look at places where we know black holes exist, because we’ve measured them from the motions of the stars around them, but that are very faint. These are so much fainter than something like a quasar, which is where the black hole is devouring as much material as it can. The black holes I’m interested in are just sipping their material, and they’re much more typical of the average black hole in the universe. We’re basically looking unique signatures in this wavelength spectrum that will tip us off to a black hole is present. One of the objects we’ll focus on is the first one ever photographed.

- by Lisa Potter, first published at @theU



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SRI Team

SRI Team

Josh Steffen, Ph.D.

Associate Professor Lecturer

Josh Steffen, Ph.D.

Associate Professor Lecturer
Josh received his BA in biology and secondary education from St. Olaf College. He carried his Ph.D. and post-doctoral research at the University of Utah where he studied plant reproductive development with Gary in the lab of Gary Drews. He carried out post-doctoral research in the lab of Richard Clark where he studied natural variation in gene expression. Over the past 8 years he has held faculty positions at Colby-Sawyer College and Utah Valley University where he focussed on undergraduate education. In 2018 he accepted a position in the School of Biological Sciences at the University of Utah. Currently, Josh manages the Science Research Initiative (SRI), teaches courses associated with the SRI, and mentors multiple undergraduate research groups. Undergraduates working with Josh are using metagenomic approaches to characterize pollinator foraging behaviors, attempting to identify novel antimicrobials, and carry out genetic analysis of maize mutants.

Heather Briggs, Ph.D.

Associate Instructor

Heather Briggs, Ph.D.

Associate Instructor
Heather completed a M.S. at the University of Michigan (Natural Resources) and a Ph.D at the University of California, Santa Cruz (Environmental Studies & Ecology and Evolutionary Biology). She went on to complete two postdoctoral positions, first at Harvard, then at UC Irvine. Heather now helps manage the SRI where she empowers students to work through hypothesis generation, experimentation, and interpretation. As an evolutionary community ecologist, Heather’s research is motivated by the desire to understand how variation in community context influences the outcome of biotic interactions. Through the exploration of the various determinants of insect behavior, plant ecology, and floral evolution, her research considers the importance of context-dependent interactions from both the plant and pollinator perspectives.

Ryan M. Stolley, Ph.D.

Associate Instructor

Ryan M. Stolley, Ph.D.

Associate Instructor
Ryan received his BS in chemistry from Fort Lewis College and Ph.D in organic chemistry from the University of Utah. He then conducted a post-doctoral appointment at Pacific Northwest National Laboratory’ Center for Molecular Electrocatalysis. After PNNL, he was a AAAS Science and Technology Policy Fellow in the US Department of Energy’s Solar Energy Technologies office. Ryan is currently an assistant research professor in the chemistry department where he works with numerous groups as a synthetic chemistry specialist, co-director of the SRI, and chairperson of the Salt Lake section of the American Chemical Society. Ryan’s research is in fundamental organic and organometallic chemistry uncovering new reaction paradigms using underexplored or entirely new functional groups, exotic ligands for rare-earth element coordination, and a variety of exotic conducting materials.



SRI Students

Learn By Doing in the SRI

Want to learn how to conduct research and create connections with faculty and other College of Science students? Join the Science Research Initiative (SRI)!

SRI offers College of Science students the opportunity to participate in discovery-based scientific research starting on your first day on campus, with no prior research experience required. You will gain research skills that will help you in science classes, learn with College of Science peers, and connect with faculty across the University. The SRI will jumpstart your path academic success, and give you needed skills to prepare for an internship or a career - whether that's in a research lab, an office, or one of the many other opportunities open to our graduates. Find out more below, or email us for more information.

Fall Year 1

Enroll 1-credit class in which you will learn about how science happens, become a part of a community of researchers, culminating with placement in a lab focused on your research interests.

Spring Year 1

Begin scientific journey in your selected lab. Students engage in research activities for roughly 10 hours per week.

Fall Year 2

Continue in your research stream and grow as a researcher. Students are provided opportunities to share research findings and mentor new students.


Stay involved with the SRI community. Connect with new research and professional development opportunities.