Sung-Won Lee<\/a>, department chair.<\/p>\n\u201cThis study is an outstanding achievement that showcases the international stature and research excellence of the Texas Tech astrophysics program,\u201d he said. \u201cBy combining observations from around the world and transforming the nova\u2019s data into sound, the team has opened an innovative pathway for exploring and communicating astronomical discoveries.\u201d<\/p>\n
For Acharya, the opportunity to work on a real stellar explosion was especially meaningful.<\/p>\n
\u201cThe chance to study a star was deeply meaningful to me,\u201d said Acharya. \u201cGrowing up in Nepal, there wasn\u2019t much awareness or conversation about astronomy, but the night sky was so clear and beautiful that it was impossible not to ignore. The stars themselves were the reason I became interested in this field. There was a moment when they stopped being twinkling dots and revealed themselves as entire worlds, the universe itself.<\/p>\n
\u201cThat shift changed everything for me. My curiosity grew from wondering why stars twinkle to exploring why they brighten, erupt and evolve. Texas Tech, and especially Dr. Aydi\u2019s patient guidance, helped me build the foundation to turn that curiosity into real research.\u201d<\/p>\n
A nova occurs when a dense stellar remnant, known as a white dwarf, pulls material from a companion star. As that material builds up on the white dwarf\u2019s surface, it can trigger a sudden thermonuclear explosion, causing the system to brighten dramatically.<\/p>\n
Novae occur fairly regularly in the Milky Way with about 10 to 15 discovered each year. Because they take place within our own galaxy, astronomers can study them in far greater detail than many stellar explosions in distant galaxies.<\/p>\n
Aydi explained that although scientists have long studied these explosions, recent discoveries have changed how researchers understand these events.<\/p>\n
\u201cAbout 15 years ago, NASA\u2019s Fermi gamma-ray satellite detected strong high-energy gamma rays from novae,\u201d Aydi said. \u201cThis was not expected at all, so we had to rethink how these explosions happen. It turned out there is a lot we don\u2019t know, and what we thought we understood very well, apparently, we don\u2019t understand at all.\u201d<\/p>\n
These discoveries led astronomers to explore how novae could produce such energetic radiation. One explanation centers on shock waves. During a nova eruption, gas can be ejected at different speeds. Later faster-moving material may collide with gas ejected earlier, creating powerful shocks.<\/p>\n
\u201cThese later ejections slam into the earlier ones, creating shock waves that lead to high-energy emission,\u201d Aydi said.<\/p>\n
The shocks also heat the surrounding gas, causing it to radiate at visible wavelengths. Recent studies have shown that much of the visible light typically observed from novae, long thought to come primarily from nuclear reactions on the surface of the white dwarf, may instead originate, at least in part, from the shock-heated gas.<\/p>\n
\u201cThis has further changed our understanding of how these explosions unfold, Aydi said. \u201cWe now know that novae are far more complex than once thought, and that they can serve as important laboratories for understanding other stellar explosions across the cosmos, especially because they occur relatively nearby in astronomical terms.\u201d<\/p>\n
Nova V612 Scuti was particularly interesting because it showed major flares, or jumps in brightness, for several months after the initial explosion was discovered.<\/p>\n
\u201cThe jumps within the explosion were extreme,\u201d Aydi said. \u201cWe had a huge amount of energy somehow released after the explosion happened, and we didn\u2019t know what was causing it. One of our hypotheses was that, after the initial explosion, there were subsequent substantial ejections of gas colliding with previously ejected material, creating powerful shock waves. The challenge was to confirm this using observations and detailed analysis.\u201d<\/p>\n
To investigate the eruption, the researchers used spectroscopy, a technique that separates light into different wavelengths, much like spreading light into the colors of a rainbow. This allows astronomers to measure how strongly the object emits at different wavelengths and to track the motion of gas during the explosion.<\/p>\n
Astronomers around the world observed V612 Scuti using spectroscopy and shared their data with the broader scientific community. The Texas Tech team used those observations to examine when the brightness jumps occurred, what caused them and how the gas moved during the eruption.<\/p>\n
Aydi said the team found evidence that new ejections occurred with each jump in the light curve. By studying shifts in the spectra, they were also able to calculate the velocity of the material. Over several months of observations, they found that the gas increased significantly in velocity with each major jump.<\/p>\n
The team decided to take the analysis a step farther.<\/p>\n
\u201cWe had high-resolution spectra, which measure intensity versus frequency, and we said, \u2018We can actually convert this extensive set of data into an equivalent of sound.\u2019\u201d Aydi said. \u201cSo, we converted the intensity of light into sound pitch and the frequency of light into frequency of sound.\u201d<\/p>\n
The process allowed the researchers to hear how the explosion changed over time. When the nova\u2019s brightness jumped, the sound changed as well. The team could not only see the evolution of the explosion in the data, but also could hear it.<\/p>\n
The sound also makes the discovery more accessible, including for people who are visually impaired.<\/p>\n
\u201cIt is very difficult to transform astronomy data into audio data,\u201d Aydi said. \u201cYou need really good data, and when we were working on this, I thought it was a perfect example. We had enough data because of the almost daily observations astronomers were taking, which allowed us to turn this set of spectra into a continuous sound that visually impaired people could listen to and use to imagine what was happening.\u201d<\/p>\n
Acharya carried out much of the data analysis, including creating the figures for the paper and producing the sonification.<\/p>\n
\u201cShe created the graphs we are publishing in the paper, and she also did the sonification of the data,\u201d Aydi said. \u201cWe experimented with multiple types of codes and decided on one that would make the sound as clear as possible for someone who could not see the data.<\/p>\n
\u201cThis is significant scientifically because we are confirming something with the data for the first time in a very strong way. It is also significant because the work was done and led by Texas Tech students.\u201d<\/p>\n
Along the way, Acharya gained valuable experience in coding, spectroscopy and astronomical data analysis.<\/p>\n
\u201cI realized how it works bit by bit, code by code, and what the sonification script actually does,\u201d she said. \u201cWhen I did it all by myself and changed the wavelengths into frequencies and produced a sound, it felt like the best thing I had ever done, and it\u2019s something I will never forget.\u201d<\/p>\n
Aydi said involving undergraduates in significant research is a point of pride for the Department of Physics & Astronomy.<\/p>\n
\u201cWe are living in a very competitive academic world,\u201d he said. \u201cOur aim is that when our undergraduate students graduate and want to apply for graduate school, they already have the experience, the skills and the achievements that allow them to be competitive. This project is a clear example of the pioneering work we do with our students.\u201d<\/p>\n
Lee said the project reflects the department\u2019s emphasis on challenging students to stretch themselves academically.<\/p>\n
\u201cIt is especially noteworthy that this project was led by our very own undergraduate student, Pragati Acharya, whose leadership reflects both her remarkable potential and the strong research environment cultivated by Dr. Aydi and our astrophysics group,\u201d Lee said. \u201cI extend my sincere congratulations to Dr. Aydi\u2019s team, particularly Pragati, for conducting this study with exceptional excellence.\u201d<\/p>\n
For Acharya, the project has been unforgettable.<\/p>\n
\u201cI cannot imagine this whole thing, but it actually feels like, \u2018OK, I did something I always wanted to do.\u2019 It\u2019s why I chose physics,\u201d she said. \u201cYou want people to hear you and understand your perspective on how you see the world and understand it. Overall, it feels like you are doing something meaningful for humanity and for science.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"Above: artistic impression of a nova explosion showing multiple ejections traveling in different directions. Photo credit: NASA\u2019s Goddard…\n","protected":false},"author":2,"featured_media":413641,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[77],"tags":[7260,18,19,17,941,452,133,16187,238047,82,147120],"class_list":["post-556614","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-all-journal-news","tag-eire","tag-ie","tag-ireland","tag-newswise","tag-physics","tag-science","tag-space-and-astronomy","tag-stellar-explosionnova","tag-technology","tag-texas-tech-university"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@ie\/116820966615762212","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/556614","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=556614"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/556614\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/413641"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=556614"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=556614"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=556614"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}