Benjamin Boe

Solar Astronomy Graduate Student

Institute for Astronomy, University of Hawaii



I am a fifth year graduate student at the Institute for Astronomy (IfA) at the University of Hawaii working toward a PhD. My primary research interests are studying the Sun's outer atmosphere known as the solar corona, and understanding the formation process of the solar wind and the resulting space weather. A database of calibrated observables from the 2015 and 2017 total solar eclipses can be found here.

Solar Corona

I am working on solar coronal research with Dr. Shadia Habbal for my PhD thesis project using data from a Total Solar Eclipse (TSE). In the course of my work I traveled to three TSE expeditions (2016 Indonesia, 2017 USA, and 2019 Chile), to make scientific observations with imagers and a spectrometer. I assisted in the construction and preparation of instruments for each TSE, including 2 new 3-channel spectrometers based on a 2-channel prototype.

In my first publication on Solar Physics, I demonstrated the power of TSE forbidden emission line observations by measuring freeze-in distances of Fe10+ and Fe13+ in the corona for the first time. The ionic freeze-in distance is the location where ions reach fixed ionization states that are adhered to during their expansion with the solar wind. It is a crucial distance in the corona that defines properties of the solar wind in interplanetary space. These measurements were made using narrow 0.5 nm bandpass filters centered on the Fe10+ (Fe XI, 789.2 nm) and Fe13+ (Fe XIV, 530.3 nm) forbidden emission lines taken during the 20 March 2015 total solar eclipse. We found that the two ions froze-in at different heliocentric distances throughout the corona. In polar coronal holes the freeze-in distance was around 1.45 Rs for Fe10+ and below 1.25 Re for Fe13+. Along open field lines in streamer regions, Rf ranges from 1.4 to 2 Re for Fe10+ and from 1.5 to 2.2 Re for Fe13+. Click here for the publication,

White light image of the solar corona during the 20 March 2015 Total Solar Eclipse (TSE) seen from Svalbard, Norway, overlaid with ionic freeze-in distance measurements of Fe10+ and Fe13+ from Boe et al. 2018.

In my most recent paper, we used data from the 2017 total solar eclipse -- with the same type of systems as used in 2015. We calibrated the line emission observed in each system to infer the line to continuum (L/C) ratio and infer an electron temperature (Te). We had multiple sites across the path of totality from Oregon to Nebraska, which enabled the determination of changes in the corona over the 28 minutes between the times of totality. The changes were driven by a Coronal Mass Ejection (CME) that was in the corona during the eclipse. Click here for the publication.

Change in the inferred Te over 28 minutes between Mitchell, OR and Alliance, NE during the 2017 Total Solar Eclipse (TSE). Figure from Boe et al. 2020.

My current thesis research is expanding this freeze-in distance analysis to multiple data sets from other TSEs, and adding novel analysis including a metric of the electron temperature of the plasma in the corona using emission ratios of different coronal lines.

Long Period Comets

At the IfA two research projects are required for an masters degree from the prior to continuing for a PhD. One of my two project involved studying the solar corona with data taken during a Total Solar Eclipse (TSE) advised by Shadia Habbal, and is the groundwork for my upcoming thesis research (see above). My other research involved modeling the detection efficiency of the Pan-STARRS1 (PS1) survey at finding long period comets (LPC) using the Moving Object Processing System (MOPS). I simulated observations made with PS1 of synthetically generated LPCs, determining the detection efficiency of PS1 as a function of each orbital parameter (i.e. perihelion,eccentricity, etc.). I then unbiased, or corrected, the orbital and size frequency distributions of observed LPCs for the first time with these efficiencies. A publication on this research, advised by Dr. Robert Jedicke, has been published in the AAS journal Icarus. Click here for the publication,. We inferred the size distribution of long period comets to smaller sizes than ever before, and found fewer small comets than what was previously expected. This turn-over hints that there are currenlty unknown physical processes that limit the number of small comets in the Oort cloud, either during their formation, or by some dynamical process over the age of the solar system.

Figure from Boe et al. 2019 showing the efficiency of detecting long period comets by PS1 as a function of size (left). We then debiased the osberved sample to infer the true size distribution of long period comets in the Oort cloud (right).

Musical Acoustics

During my undergraduate education at the University of Puget Sound, I was funded by a Washington State NASA Space Grant to do acoustics research with Dr. Randy Worland. I studied coupled vibrations between two drumheads and the air cavity inside the body of a drum. I used a table top optical setup to measure vibrational modes on a drum, and I developed a computer model (in COMSOL Multiphysics) to study the coupled system. I found that air modes in the drum could drive additional drumhead mode phases. I won awards for my work including the John Van Zytveld Award in Physical Science in 2013, and a poster award at the Acoustical Society of America (ASA) conference in 2013. I had a published a paper on this research in the ASA journal.

The experimental setup I used to observe mode coupling between drumheads.

Completion of PhD

Eclipse expeditions
Years of Research

Contact Me

Honolulu, HI, US         Email: bboe@hawaii.edu


Education for the next generations is as crucial an effort for scientists as groundbreaking research. Only with an educated public will we continue to recieve funding and have the benifits of our work understood and fully utilized. In my career I have strived to excell not only in academic research but also in education through both formal teaching and scientific outreach with the public.


In the 2017-2018 academic year I was the lead instructor of a 110 Astronomy laboratory course, and was responsible for all lectures and course material. In addition to using some existing curriculum, I created a computer lab about Sunspots and Coronal Mass Ejections (CMEs). The follwing summer (2018, and again in Summer 2020) I was the sole instructor of a Astronomy 110 course, involving 6 weeks of daily lectures using a curriculum that I developed from scratch. I also have several years experience as a teaching and lab assistant beginning in my second year of my undergraduate studies.

Science Outreach

My thesis work studying the corona and the solar wind has direct implications for life on earth and offers unique opportunities for public outreach around the world. In Indonesia, Nebraska, and Chile I taught many locals about solar eclipses and how to safely observe the event with solar glasses that we distributed. I will continue my outreach efforts at future eclipses and help to spread a greater appreciation for science worldwide.

I volunteer for the Maunakea Scholars program in collaboration with another graduate student in a high school classroom where students propose for time on several Maunakea telescopes. I work with students to refine their original research ideas, help them prepare telescope proposals and assist them with data analysis to produce results for science fairs and senior projects. One of my students from 2017-2018 won an award at the local science fair and presented at the Hawaii state science fair.

In addition to my focused mentoring outreach, I regularly participate in events for the general public as well as at local K-12 schools engaging in scienfic education using telescopes to show students nebulae, comets, planets and star clusters, or with spectroscopy demonstrations using gas tubes and diffraction gratings. I have also assisted in running demonstrations at the IfA yearly open house where members of the community are invited to tour our facilities and see scientific demonstrations.

As an undergraduate I was an active member of my university's physics club where I served as president for three years. As part of physics club I worked with fellow club members on physics and engineering projects such as constructing a bike powered electric generator, a Rubin's tube, as well as launching and recovering a camera and instrument payload from near space using a weather balloon. The Physics club's success drew the attention of the university's board of trustees, resulting in the participation of club leadership in a trustee's workshop discussing how to provide more extracurricular academic learning opportunities for students on our campus.


  • Maba, Halmahera, Indonesia
  • March 19, 2016

    Total Solar Eclipse Blog
  • Alliance, Nebraksa, United States
  • August 21, 2017

    Total Solar Eclipse Blog


Video about my 2018 Freeze-in distance publication

University of Hawaii Solar Eclipse Interview

48th Division for Planetary Sciences Talk

University of Puget Sound Physics Club Weather Balloon