Tanja Petrushevska's webpage

Strongly lensed supernovae

Gravitational lenses such as galaxies and galaxy clusters, can magnify the flux of background galaxies. These galaxies at high redshift can host supernovae which, thanks to the magnification boost due to lensing, can be observed, otherwise too faint to be detected by current telescopes. Under the right circumstances, the background galaxies may also have multiple images due to the strong lensing. Of particular interest is to detect lensed supernovae of type Ia, because of their standard brightness. They could help improve lensing models and, if multiple images are observed, the Hubble constant can be measured independently. You can read about my work on strongly lensed supernovae here.
It is quite exciting that just in recent years, we have detected the multiple images from gravitationally lensed Type Ia supernovae ( iPTF16geu , SN Zwicky, SN H0pe and SN Encore).

Luminous flares from the nuclear regions of galaxies

Thanks to the advent of large-scale optical surveys, a diverse set of flares from the nuclear regions of galaxies has recently been discovered. These include the disruption of stars by supermassive black holes at the centres of galaxies - nuclear transients known as tidal disruption events (TDEs). Active galactic nuclei (AGN) can show extreme changes in the brightness and emission line intensities, often referred to as changing-look AGN (CLAGN).  Given the physical and observational similarities, the interpretation and distinction of nuclear transients as CLAGN or TDEs remains difficult. One of the obstacles of making progress in the field is the lack of well-sampled data of long-lived nuclear outbursts in AGN. In our recent work on PS16dtm, we studied a nuclear transient in a Narrow Line Seyfert 1 (NLSy1) galaxy which has been proposed to be a TDE candidate. There, we showed our multi-year spectroscopic and photometric study of PS16dtm, which can help us to better understand the outbursts originating in NLSy1 galaxies. Read here our recently published paper on PS16dtm.

In another study, led by Philip Wiseman from the University of Southampton, we reported the observations and the analysis of the most energetic non-quasar transient ever observed, AT2021lwx. It appeared in Guardian, BBC, Time, New York Times.

Axion dark mater search

The nature of dark matter, the substance that accounts for more than 85% of all matter in the Universe, remains a mystery. Many theories predict that dark matter is made up from yet – undiscovered fundamental particles. A plethora of ground-based and space born experiments are looking for traces of these particles. Together with Dr. Manuel Meyer , we use explosions of stars outside of our Milky Way to search for a particular class of dark matter particles. Read here our press release or our paper published in Physical Review Letters.

Collaborations

I am a member of the following international collaborations:

Previous teaching

School of Science, University of Nova Gorica

Petnica Science Center, Serbia

Physics Department, Stockholm, Sweden

School of Science, University of Nova Gorica, Slovenia

I am the coordinator for promotional activities of the School of Science, University of Nova Gorica. Here are some of the events for the public that we have organized, more can be found here.

• 2025 January - Astronomical event in Ilirska Bistrica, stay tuned!
• 2024 December 3 - Astronomical evening (lecture + telescope observations) in Vipava. For more info, see here.
• 2024 October 11 - INSPIRO symposium for undergraduate research student projects. FN students, Amalija Rafaj Škriljevečki, Nejc El Habashi and Angela Zorchec (supervised by me), presented their work. More info here.
• 2024 August 25-31 - Third Gochile summer school
• 2024 May 22 - FN students have a stand with experiments at Parade of knowledge, from 15:00 on, on Lavričev trg in Ajdovščina.
• 2024 February 16-17 - UNG Info days, full program here.
• 2024 February 2nd - Ilirska Bistrica - Astronomical evening with a lecture, experiments, quiz and telescope observations.
• 2023 August 13-19 - 2nd Gochile summer school summer school.
• 2023 May 24th - As part of the Parade of knowledge ( Tednih vseživljenjskega učenja) our students made an amusing resonance plate and showed it at the stand during the fair in the square of Ajdovščina.
• 2023 May 29th - We hosted the pupils from the primary schools OŠ Šturje and OŠ Col, they had the chance to do an interactive experiment in our Materials Science lab and visit the labs. They also listened to a lecture by prof. Andreja Gomboc.
• 2023 May 15 - We hosted the high school students from Veno Pilon, they had the chance to listed to a lecture by prof. Andreja Gomboc and visit our research labs.
• 2023 February 16-18 - Open days at the School of Science, University of Nova Gorica. More here and and here.
• 2023 January 26- We hosted 45 high school students from Slovenska Bistrica, they had the chance to hear a presentation about our faculty and the research we are doing.
• 2022 November 7th, a public outreach event in the Amphitheater of the School of Science in Ajdovščina. The event consisted of a public lecture, followed by telescope observations of the Moon, Jupyter, and Saturn. The event was organized in collaboration with the Astronomical society Nanos, the Veno Pilon high-school, and local primary schools.
• 2022 October 7th, during the activities of the University Week 2022, we held a stargazing party in the public library in Nova Gorica. More here.
• 2022 - First summer school in astronomy with the Slovenian GoChile telescope More here.
• 2022 - Taborniki zlet. We have been invited to participate at the largest scout event in Slovenia, there were 700 high school students and 300 volunteers. The first day, in the afternoon, we had a presentation of the FN study programs, and some of the research we do at the Center of Astrophysics and Cosmology. Then in the evening, we did telescope observations of the moon, Andromeda galaxy, Messier objects etc. After the Moon set, We also explored the constellations and took photographs of the Milky way. The second day, the weather was not good, but we had we a quiz with prizes, and we managed to do some moon observations with Andrej Guštin.

• 2022 - We hosted students of the secondary school from Gorizia, Italy for their internship, read more here
• 2022 - Organizing the Open Days for the School of Science (11-13.02.2022, 17.05.2022, 17.09.2022 ...) - During these days when Slovenian universities open their door for high schools students, we were able to do presentations and visits to the labs in person! Furthermore, the all the vents were in hybrid mode, which means that the visitors had chance to attend the events online as well.
• 2021 European Researchers’ Night
• 2019, as part of the University week, an astronomical evening with various fun experiments, telescope observations and a lecture.



• 2019 European Researchers' Night (Science Espresso, fun experiments, telescope observations and a lecture).
• 2019 - From Solar eclipse to black holes: Celebration of the 100th anniversary of the Solar eclipse which confirmed Einstein's theory of relativity. (a lecture and telescope observations).
• 2019 Celebration of Woman day in Astronomy (lecture, quizzes and sky observations).

• 2018 Within University Week of the UNG (a lecture, three interactive workshops and telescope observations.
• 2018 Einstein Day (Lecture about Einstein contribution to physics and interactive workshop)

Physics department, Stockholm University, Sweden

• During my time at Stockholm Unviersity, I have been involved in the outreach project Fysikshow which aims to bring closer physics to young students by performing experiments. You can read more about our activities from 2016, 2015, 2014.
  

• In 2016, together with Semeli Papadogianakis, we have organized a summer research school for talented high-school students. Short description about that is here.
  
• In the project Inner & Outer Cosmos, Our Universe expands, a collaboration between researchers and artists (for ex. I collaborated with the artist Dalibor Trencevski) resulted in this exhibition in the Edviks Konsthall.
  
• As part of several outreach events, we created a Cosmic cocktail.
• My image of the galaxy M82, was selected and displayed at the ArteScienza exhibition.
  

• 2024 "Webb Researchers Discover Lensed Supernova, Confirm Hubble Tension" - on NASA website.
• 2023 Radio interview on supernovae and cosmology: Available on Rai Play Sound
• 2023 Article about the LSST@Europe5 conference organized by University of Rijeka, University of Belgrade, Rudjer Boskovic Istitute and our group at UNG. Here an article in English and here in a Slovenian newspaper .
• 2023 "Astronomers capture largest cosmic explosion ever witnessed" - press release for Wiseman et al. 2023 including Petrushevska, appeared in Guardian, BBC, Time, New York Times
• 2021 In the show Ugriznimo znanost on the Slovenian national tv, I discussed how astronomers measure distances in the Universe. Watch the episode here.
• 2020 Press release on Hunting dark matter with supernovae
• 2020 Article in the Slovenian newspaper Delo: Iskanje narave temne snovi
• 2018 RTV SLO 1: Odmevi Slovenska raziskovalka opazovala nenavadno supernovo
• 2018 - "Ultra-Stripped Supernova Produces Neutron Star Binary" for De et al. including Petrushevska 2018, Caltech press.
• 2018 Popular science article in the Slovenian newspaper DELO: Stars explode also on Sundays.
• 2017 - "Light rays from a supernova bent by the curvature of space-time around a galaxy" for Goobar et al. including Petrushevska 2017, Stockholm University and Caltech press.
• 2014 - "The Nearest Standard Candle Supernova in Several Decades" for Goobar et al. including Petrushevska 2014, Stockholm University and Caltech press.
• 2014 interview on the Swedish radio

Sem astrofizičarka in docentka na Centru za astrofiziko in kozmologijo, Univerze v Novi Gorici.
Moji raziskovalni interesi so predvsem na področju opazovalne astrofizike in kozmologije, še posebej se osredotočajo na t.i. časovno spremenljivo astronomijo, pri kateri gre za preučevanje izvorov, ki s časom hitro spreminjajo sij. Moje raziskave do sedaj so pokazale, da je možno odkrivati močno lečene supernove s teleskopi na površju Zemlje. V sklopu raziskav smo odkrili pet najbolj oddaljenih supernov, pri katerih je eksplozijo povzročil kolaps sredice zvezde, hkrati pa smo preučili prostorninsko pogostost takšnih supernov pri velikih rdečih premikih. S preučevanjem lastnosti močno lečene in zelo oddaljene supernove smo pokazali, da so lahko ti izvori zelo koristni pri kozmoloških raziskavah. Kot članica kolaboracije intermediate Palomar Transient Factory sem prispevala k odkritju novih supernov in k njihovemu preučevanju, vključno s prvo razločljivo in večkrat lečeno supernovo tipa Ia in prvo supernovo, po eksploziji katere je nastala dvojna nevtronska zvezda. Trenutno se ukvarjam še s plimskimi raztrganji zvezd in iskanjem kratkih izbruhov sevanja gama nastalih pri supernovah, ki jih povzročijo aksionom podobni delci. Aksionom podobni delci so obetavni kandidati za sestavne delce temne snovi.

Članki

ARRS projekti

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