Dax L. Feliz, PhD

About Me

Growing up in Spanish Harlem, the beauty of the night's sky was often robbed from my gaze due to New York City's light pollution. That did not inhibit me from questioning what lies beyond the steel and glass towers and the artificially lit clouds above. One of the first celestial objects that captivated me was the Moon and has since been a source of my inspiration. As a child, I asked numerous questions that were sparked by my interest in astronomy..

The adults in my life, while uneducated in astronomy and physics, highly encouraged me to pursue my passion outside of the classroom. I was consumed by thoughts of astronomy but faced with the reality of my limited resources. I was inspired to look for answers in my local libraries, educational programs on television as well as frequenting the American Museum of Natural History. In spite of my lack of exposure to physics and math in my early education, I was able to develop a deeper understanding of basic astronomy on my own.

While my rudimentary understanding of astronomy grew, my questions became more precise; “Where did the Moon come from? Where did the planets in our solar system come from?”, “Are there other planets out there?” or “What kind of planets can host life similar to Earth?”. These are the questions that continue to fuel my passion for astronomy. I am currently a Postdoctoral Researcher in the Astrophysics department of the American Museum of Natural History in NYC.

Some more details on my recent work can be found on my Research page.

Recently, my collaborators and I have become involved in the development of a light curve extraction and transit searching pipeline using data from the TESS mission in order to find exoplanets that orbit cool, red stars.

Research

Period-radius diagram of all confirmed transiting exoplanets and exoplanet candidates observed in TESS sectors 1 – 5 from Figure 9 of Feliz et al. 2021.

A Multi-Year Search For Transits Of Proxima Centauri

Proxima Centauri has become the subject of intense study since the radial-velocity discovery by Anglada-Escudé et al. 2016 of a planet orbiting this nearby M-dwarf every ~ 11.2 days. If Proxima Centauri b transits its host star, independent confirmation of its existence is possible, and its mass and radius can be measured in units of the stellar host mass and radius. There have been numerous independent surveys and analyses of the Proxima system in search of transit events. Using a global network of small telescopes, we have obtained light curves of Proxima Centauri at 329 observation epochs from 2006 - 2017.

In Blank et al. (2018), we analyzed 96 of our light curves that overlapped with predicted transit ephemerides from previously published tentative transit detections, and found no evidence in our data that would corroborate claims of transits with a period of 11.186 d. In Feliz et al. (2019), we broaden our analysis, using 262 high-quality light curves from our data set to search for any periodic transit-like events over a range of periods from 1 - 30 days. Specifically at the 11.186 d period and 5 millimagnitude transit depth, we rule out transits in our data with high confidence with a transit injection analysis. We are able to rule out virtually all transits of other planets at periods shorter than 5 days and depths greater than 3 millimagnitudes; however, we cannot confidently rule out transits at the period of Proxima b due to incomplete orbital phase coverage and a lack of sensitivity to transits shallower than 4 millimagnitudes.

An artist’s impression of Proxima Centauri b. Credit: ESO.

Media

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Elements

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