The NEID spectrograph has passed the Operational Readiness Review necessary for final acceptance and regular operations. Developed by NASA and the National Science Foundation's NN-EXPLORE exoplanet science program, it has been put through a lengthy commissioning process in the five years since the radial velocity planet hunter design was selected. NEID is mounted on the WIYN 3.5m telescope at Kitt Peak National Observatory in Arizona, and we now have word that its scientific mission has begun. Image: Sunset over Kitt Peak National Observatory during NEID commissioning in January 2020. Credit: Paul Robertson. As a radial velocity instrument, NEID is all about the tugs one or more planets exert on the host star, as measured radially -- toward Earth, then away from it -- during the planets' orbits. The Doppler shift in the star's light contains the information. That these are exquisitely tiny measurements should be obvious. Jupiter induces a 13 meter per second wobble on our star, but...

300 light years from Earth in the constellation Musca, the gas giant TYC 8998-760-1 b, along with a companion planet, orbits an infant K-class star about 17 million years old. We're probably looking at a brown dwarf here rather than a gas giant like Jupiter, for TYC 8998-760-1 b is about 14 times Jupiter's mass, nudging into brown dwarf territory, and it appears to be roughly three times as large, unusual for brown dwarfs. The planet's separation from its host star is pegged at 160 AU. An inflated atmosphere due to processes still unknown? We don't know, but both this and the companion planet have been directly imaged. Now TYC 8998-760-1 b resurfaces through work with the European Southern Observatory's Very Large Telescope, as reported in the latest issue of Nature. Led by first author Yapeng Zhang (Leiden University, The Netherlands), the team of astronomers detected carbon isotopes in the object's atmosphere, showing higher than expected carbon-13 content. Here is the image, first...

Demonstrating once again the role amateurs can play in supporting ongoing observations, a new project linking NASA and the American Association of Variable Star Observers is being launched. Exoplanet Watch isn't about discovering new transiting planets (although the potential is there) as much as tightening up the information we already have about planets currently under investigation. The idea is to help professional observers know when to look, which allows them to maximize precious observing time on instruments that are always in high demand. Transit timing is the key, and the fact is that for many known exoplanets, knowing exactly when to look is problematic. Rob Zellem (JPL) is project lead for Exoplanet Watch: "If there's a 15-minute under-estimate of when a transit will occur, that's an extra 15 minutes I have to build into my observing scenario. Time on big telescopes, especially space telescopes, is very, very precious. If you're observing a lot of planets, [15 minutes]...

Many of the planet-hosting stars being identified by TESS, the Transiting Exoplanet Survey Satellite, may actually be binaries. Unless examined closely, a pair of stars can appear as a single object, requiring high resolution instrumentation to separate into its component parts. As it applies to exoplanet research, this is a problem, for TESS operates by the transit method, tracking the change in a star’s light curve as a planet crosses the face of the star. Light curves yield precious information, but the presence of a second star unknown to researchers can obscure smaller, rocky worlds, just the kind of object we’d like to eventually identify as an Earth 2.0. The problem seems to be wider than we have realized, given that about half of all stars exist in binary systems. New work has put some numbers on the problem. Conducted with data from the Gemini Observatory and the WIYN 3.5-meter telescope at Kitt Peak by NASA Ames researchers, the study examined TESS host stars using a...

Nu2 Lupi is a G-class star not all that far away in astronomical terms (48 light years) in the constellation Lupus, its proximity verified by parallax measurements and firmed up by the Hipparcos satellite. This is one of the closest G-class stars to our own, and it’s a fast mover in other ways, with a high radial velocity. Its age is estimated at roughly 12 billion years, making it one of the oldest stars near our system. HARPS spectrograph data pulled up three planets here in 2019, two of them later found to transit. And now we have, unexpectedly, a third transit. The surprising nature of the third relates to the distance of the third planet from the star. The two inner worlds, with masses between Earth’s and Neptune’s, take 12 and 28 days to orbit Nu2 Lupi. The third takes 107 days, far enough out that a transit seemed unlikely. The ratio of the diameter of the star to the diameter of the orbit comes into play in determining the probability of a transit. We have the European Space...

Call it the Earth Transit Zone, that region of space from which putative astronomers on an exoplanet could see the Earth transit the Sun. Lisa Kaltenegger (Cornell University) is director of the Carl Sagan Institute and the author of a 2020 paper with Joshua Pepper (LeHigh University) that examined the stars within the ETZ (see Seeing Earth as a Transiting World). While Kaltengger and Pepper identified 1004 main sequence stars within 100 parsecs that would see Earth as a transiting planet, Kaltenegger reminds us that stars are ever in motion. Given the abundant resources available in the European Space Agency's Gaia eDR3 catalog, why not work out positions and stellar motions to examine the question over time? After all, there are SETI implications here. We study planetary atmospheres using data taken during transits. Are we, in turn, the subject of such study from astronomers elsewhere in the cosmos? Thus Kaltenegger's new paper in Nature, written with Jackie Faherty (American...

The Allende meteorite is the largest carbonaceous chondrite meteorite ever discovered. Falling over Mexico's state of Chihuahua in 1969 and breaking up in the atmosphere, the object yielded over two tons of material that have provided fodder for scientists interested in the early days of the Solar System. The meteorite contains numerous calcium-aluminum-rich inclusions (CAIs), which are considered to be the first kind of solids formed in the system 4.5 billion years ago. Samples of the Allende meteorite are considered 'primitive,' which in this parlance means unaffected by significant alteration since formation. Now a team led by Tom Zega (University of Arizona Lunar and Planetary Laboratory) has gone to work on a dust grain from this object, in order to simulate the conditions under which it formed in the Sun's protoplanetary disk. The grain was drawn from one of several CAIs discovered in the Allende meteorite sample. Analysis of the sample's chemistry and crystal structure...