SDSU astronomers pinpoint two new 'Tatooine' planetary systems

January 07, 2020

Astronomers announced Monday the first discovery made by NASA's TESS mission of a two-star planetary system. Led by researchers at NASA's Goddard Space Flight Center and San Diego State University, with other collaborators, the telescope satellite's finding marks the start of a much better understanding of the population of such planetary systems.

On behalf of the international team of 60 investigators, the work was presented by researcher Veselin Kostov at the 235th meeting of the American Astronomical Society in Honolulu.

The new planet, called TOI-1338 b, is about 6.9 times larger than Earth. It orbits its pair of host stars every 95 days. One of the stars is more massive and much brighter than the other, and as the planet orbits around it blocks some of the light from the brighter star. This transit allows astronomers to measure the size of the planet. The transit was first found in the TESS data by a high school student working at NASA with Kostov over the summer.

"Our analysis confirmed the transit was caused by a circumbinary planet and we were able to measure the planet's properties," said SDSU astronomer Jerome Orosz.

A dozen such Tatooine-like planets--so named for the desert world in "Star Wars"-- were found with NASA's Kepler Mission, which ended in 2013. The orbiting TESS telescope, launched in 2018, will cover nearly the whole sky and enable many more discoveries, perhaps as many as 100 new circumbinary planets. A sample size that large will allow a statistical analysis of the population, which to date has not been possible because too few systems are known.

New Kepler planet

Helping to boost the numbers, SDSU astronomers at the AAS meeting also revealed a new Kepler circumbinary planet, called KOI-3152 b.

"We first noted convincing evidence for this planet in 2012, but confirmation required additional data and improvements in computer modeling," said SDSU astronomer William Welsh. "In particular, star spots on the primary host star and a weak eclipse signal from the second star made the analysis difficult."

In 2019, Welsh's master's thesis student Quentin Socia accepted the challenge and spearheaded the investigation.

KOI-3152 b is located 1,347 light-years away and is 3.9 times the size of the Earth. It orbits its binary stars every 175 days. Although KOI-3152 b straddles the hot edge of the habitable zone, it is a low-density gaseous planet and not able to support life as we know it. This work has been accepted for publication in The Astronomical Journal.

This finding marks the latest discovery made by the SDSU team using Kepler Mission data. Their pioneering work established this new type of planet and includes the discovery of the most interesting of the circumbinary planets, the Kepler-47 system, consisting of three planets orbiting two stars.
-end-
This work was supported in part by grants from NASA and the National Science Foundation, and by a donation to San Diego State University by John Hood, Jr.

"TOI-1338: TESS' First Transiting Circumbinary Planet"

Kostov, et al., 2020 Astronomical Journal (submitted)

"KOI-3152 b: A Neptune-sized Kepler Transiting Circumbinary Planet Around a Grazing Eclipsing Binary"

Socia, et al., 2020 Astronomical Journal (accepted)

San Diego State University

Related Planets Articles from Brightsurf:

Stars and planets grow up together as siblings
ALMA shows rings around the still-growing proto-star IRS 63

Two planets around a red dwarf
The 'SAINT-EX' Observatory, led by scientists from the National Centre of Competence in Research NCCR PlanetS of the University of Bern and the University of Geneva, has detected two exoplanets orbiting the star TOI-1266.

Some planets may be better for life than Earth
Researchers have identified two dozen planets outside our solar system that may have conditions more suitable for life than our own.

Fifty new planets confirmed in machine learning first
Fifty potential planets have had their existence confirmed by a new machine learning algorithm developed by University of Warwick scientists.

Rogue planets could outnumber the stars
An upcoming NASA mission could find that there are more rogue planets - planets that float in space without orbiting a sun - than there are stars in the Milky Way, a new study theorizes.

Could mini-Neptunes be irradiated ocean planets?
Many exoplanets known today are ''super-Earths'', with a radius 1.3 times that of Earth, and ''mini-Neptunes'', with 2.4 Earth radii.

As many as six billion Earth-like planets in our galaxy, according to new estimates
There may be as many as one Earth-like planet for every five Sun-like stars in the Milky way Galaxy, according to new estimates by University of British Columbia astronomers using data from NASA's Kepler mission.

How planets may form after dust sticks together
Scientists may have figured out how dust particles can stick together to form planets, according to a Rutgers co-authored study that may also help to improve industrial processes.

Planets around a black hole?
Theoreticians in two different fields defied the common knowledge that planets orbit stars like the Sun.

The rare molecule weighing in on the birth of planets
Astronomers using one of the most advanced radio telescopes have discovered a rare molecule in the dust and gas disc around a young star -- and it may provide an answer to one of the conundrums facing astronomers.

Read More: Planets News and Planets Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.