Stars tell stories about themselves, and sometimes about their undiscovered planets. Their language is light; it reveals many physical properties of a star: its temperature, pressure, motion, chemical composition, and many more. Researchers analyse the light with a method called quantitative absorption spectroscopy. Telescopes capture starlight and spectrographs break it up by wavelength into a rainbow-like spectrum which is the star's light fingerprint. When astronomers know these parameters precisely, they can use them to test their theoretical models of stars. This often reveals that the models have some shortcomings, or that observations of stellar spectra are still too imprecise.
But sometimes, it reveals that a star has a surprising story for astronomers. That is what motivated this team to make an ultra-precise survey of possible planet-hosting stars. "Because stars and their planets form together, the question arose whether the existence of certain chemical elements in a stellar atmosphere, or their isotopic or abundance ratios, is indicative of a planetary system," explains Prof. Klaus G. Strassmeier, lead author, director at AIP and principal investigator of the survey.
Astronomers have hypothesized that the amounts of different chemical elements within a star could hint that the star has terrestrial planets (rocky worlds like Earth or Mars), could suggest ages for those planets, and could even provide clues that the star has "eaten" some of its planets. This will need further investigation, and the now released data lay the foundations for such studies.
Of the over 5000 confirmed exoplanets (planets orbiting other stars than the Sun), 75% were discovered from space by observing a star's light being reduced because of a planet transiting in front of it. NASA's Transiting Exoplanet Survey Satellite (TESS) mission discovered exoplanets just this way. It yielded more exoplanets when observing those parts of the sky furthest from the ecliptic (the plane in which the Earth orbits the Sun), called the ecliptic poles. Observatories in the northern hemisphere can observe the Northern Ecliptic Pole, and this survey of potential planet-hosting stars within this region is named the Vatican-Potsdam Northern Ecliptic Pole (VPNEP) survey.
The survey concentrated on the richest observing field of TESS, an area of the sky approximately 4000 times the size of the full moon. All approximately 1,100 potentially planet-hosting stars in this field were investigated. Up to 1.5 hours of telescope time was required to gather enough of a star's light to make a single high-quality spectrum. With several visits per star, it took five years to obtain the survey data.
The survey made use of telescopes at two sites: In Arizona, the VO's Alice P. Lennon Telescope and Thomas. J. Bannan Astrophysics Facility (Vatican Advanced Technology Telescope or VATT) fed light to the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) and took spectra of dwarf stars with unprecedented precision. On Tenerife, the AIP's STELLA (STELLar Activity) Observatory used the STELLA Echelle Spectrograph to capture light of giant stars with lower, but still high, precision.
Dr. Martina Baratella, one of AIP's postdoctoral researchers involved in the survey, comments: "The spectra revealed elements that are among the most difficult to observe." Abundance ratios like carbon to iron or magnesium to oxygen hint towards the existence and age of otherwise unseen rocky planets. Prof. Strassmeier adds: "While it will take time to fully analyse the data from the survey, we expect soon to announce subsequent discoveries."
|Subscribe Free To Our Daily Newsletters
SpaceX Dragon crew enter International Space Station
NASA awards Unit Price Agreement Tracking System
DLR goes all in with new technology at the Startup Factory
Global patent filings edge higher in 2022: UN
SpaceX CRS-27 delivers truck load of research projects to ISS
Virgin Galactic to renew Spaceplane Flights
Rocket Lab set for dual launch campaigns in Virginia and New Zealand
Successful flight acceptance hot test of CE-20 cryogenic engine
NASA's Curiosity Views First 'Sun Rays' on Mars
Solid-gas carbonate formation during dust events on Mars
Got Rock Sample: Sol 3755
Perseverance from Team Curiosity: Sols 3752-3754
Shenzhou XV crew takes second spacewalk
China plans robotic spacecraft to collect samples from asteroid
China conducts ignition test in Mengtian space lab module
China's space station experiments pave way for new space technology
Intelsat completes multi-orbit inflight Wi-Fi tests
Sidus Space to integrate Edge AI for upcoming satellite constellation operations
Sure South Atlantic picks Intelsat to connect three British Island Territories
Kleos Space joins Ursa Space Virtual Constellation
NASA seeks commercial near space network services
Arralis Technologies acquired by ReliaSat
Is biodegradable better? Making sense of 'compostable' plastics
Meta slashes prices for Quest headsets to boost VR use
Can artificial intelligence help find life on Mars or icy worlds?
To new worlds with quantitative spectroscopy
Humanity's quest to discover the origins of life in the universe
Removing traces of life in lab helps NASA scientists study its origins
Newly discovered form of salty ice could exist on surface of extraterrestrial moons
New aurorae detected on Jupiter's four largest moons
JUICE's final take-off before lift-off
A new ring system discovered in our Solar System
|Subscribe Free To Our Daily Newsletters