• Research Interests

  • Dr. Ueta is an associate professor and an observational astronomer/astrophysicist in the Department of Physics and Astronomy. While there are many specific research projects at any given time, his research interests revolve around stellar mass loss process - one of the remaining missing pieces in our understanding of stellar evolution - because

    1. stellar mass loss is still not understood from the first principles of physics;
    2. we don't quite understand the stellar evolution without understanding stellar mass loss (stellar mass loss influences evolution); and
    3. we don't quite understand the chamical enrichment of the Universe without understanding stellar mass loss (stellar mass loss is the first step to eject nucleosynthesized material into the Universe).

    More broadly, Dr. Ueta's research interests are encompassed by the following topics:

    (1) stellar evolution: particularly looking into the late stages of evolution from the Red Giant to the Planetary Nebula phases involving mass loss processes

    (2) astropaleontology: investigation into the history of stellar mass loss by observing the circumstellar gas/dust distribution

    (3) astromineralogy: study of the composition and formation of circumstellar and interstellar matter, especially dust grains

    (4) radiative transfer in dusty media

    (5) observations of circumstellar phenomena using optical, infrared, sub-mm, and radio

    (6) interactions between stellar winds and the interstellar medium

    Dr. Ueta has used various space-based and ground-based telescopes/observatories around the world in the wavlength ranges from UV to optical to IR to Radio.

    There are always some research opportunities for students.  If you are interested in any of these topics and related ideas, please contact me!

  • Links

  • Contact Info (via DU Directory)
    http://www.du.edu/Directory/servlet/DirectoryServlet
  • List of Publications

  • The latest list of publications can be looked up from ADS.

    By clicking the following link, you will be performing an ADS author query.

  • Past Research Headlines

  • European Space Agency Web Release (5/16/2018)

    A rare phenomenon connected to the death of a star has been discovered in observations made by ESA's Herschel space observatory: an unusual laser emission from the spectacular Ant Nebula, which suggests the presence of a double star system hidden at its heart.

    http://sci.esa.int/herschel/60331-a-space-ant-fires-its-lasers/

  • Herschel Space Observatory Web Release (6/17/2014)

    Far-infrared emission from OH+ molecules was detected for the first time from planetary nebulae based on observations made as part of the Herschel Planetary Nebula Survey (HerPlaNS, Dr. Ueta is the PI of this project) and other programs.

    http://www.esa.int/Our_Activities/Space_Science/Herschel/New_molecules_around_old_stars

  • A&A special feature: Science with AKARI (5/3/2010)

    Ueta et al. studied the environment of the Mira-type star R Cassiopeiae, and especially the interaction of the stellar winds coming from the star with the interstellar medium. It causes dusty matter warmed up at the interface regions to become bright in the far-infrared.

    https://www.aanda.org/2010-press-releases/569-aaa-special-feature-science-with-akari-3-may-2010

  • AKARI Highlights I: A supergiant making a splash in a cosmic river (11/19/2008)

    A river of the interstellar medium meanders through deep space. When stars cross these rivers, they make astronomically large splashes. AKARI, the Japan Aerospace Exploration Agency (JAXA) infrared astronomical satellite with the European Space Agency (ESA) participation, has obtained a high-resolution image of Betelgeuse; a bright red supergiant in the constellation Orion located about 640 light year from the Earth, making such a big splash as the star goes across a cosmic river.

    http://www.ir.isas.jaxa.jp/AKARI/results/20081119_1_Betelgeuse/

  • Spitzer Space Telescope Image Release (11/30/2006)

    A bow-shock like "wake" due to intersctions between stellar winds and the interstellar medium around the low-mass asymptotic giant branch star R Hya was discovered in the far-IR emission for the first time around this type of star.

    http://www.spitzer.caltech.edu/images/2183-sig06-029-Red-Giant-Plunging-Through-Space

  • 2-Dust (2-D Dust Radiative Transfer Code) Home

    This is a code that I developed as part of my Ph.D. thesis and is made available publicly (the download site is maintained at the Space Telescope Science Institute). This code does radiative transfer within the dusty circumstellar shell possessing axisymmetry (hence the name 2-D), but actual radiative transfer is done in 3-D using the method of long characteristic.

    http://www.stsci.edu/science/2dust/index.cgi

This portfolio last updated: 12-Mar-2019 10:26 AM