All articles tagged with #radial velocity
Astronomers have revised the mass of the nearby exoplanet Gliese 3378 b down to about 2.3 Earth masses, shifting it from the edge of a mini-Neptune into the rocky regime. Its 21.45-day orbit places it in the star’s habitable zone at roughly 25 light-years away, making it a promising candidate for a rocky world; however, the existence of a solid surface or an atmosphere—and thus true habitability—still requires confirmation.
A nearby red-dwarf system hosts GJ 251 c, a candidate 3.8-Earth-mass super-Earth in the star’s habitable zone detected by radial-velocity methods; its radius and atmosphere remain unknown, but at ~18 light-years away its geometry could let future 30-meter telescopes directly image it and probe for water, air, and possible biosignatures—though no definitive signs exist yet.
Astronomers propose a method that uses spectra from magnetically quiet stars and radial-velocity analysis to efficiently spot planets. In a study of 24 stars from the Dispersed Matter Planet Project, they identified 14 stars hosting 24 exoplanets (7 new), with an occurrence rate 8–10 times higher than previous radial-velocity surveys. If scaled to about 16,000 nearby stars, the approach could reveal roughly 300 more planets around stars showing low magnetic activity, suggesting a more targeted planet search could be fruitful.
Astronomers have discovered a second exoplanet orbiting the nearby star Gliese 536 using radial velocity measurements, revealing a low-mass planet about 5.89 times the Earth's mass with a 32.76-day orbit, making it a promising target for atmospheric studies.
New research using the NEID instrument at Kitt Peak National Observatory has debunked the existence of the planet Vulcan, thought to orbit the star 40 Eridani A, by attributing the detected signals to the star's surface activity rather than an actual planet.
Astronomers have confirmed that the signals previously thought to indicate the existence of a planet orbiting the star 40 Eridani A, known as Vulcan in Star Trek, were false positives caused by the star's own activity. This finding underscores the importance of advanced tools in accurately identifying exoplanets and ruling out false signals.
A new study led by astronomer Abigail Burrows reveals that the planet thought to orbit 40 Eridani A, often compared to Star Trek's fictional Vulcan, is actually an illusion caused by the star's own activity. High-precision measurements from the NEID instrument show that the supposed planet signal is due to stellar jitters, not an actual planet.
Astronomers using the HARPS spectrograph have discovered two additional exoplanets in the GJ 367 planetary system, located 30.7 light years away. The newfound planets, GJ 367 c and GJ 367 d, are at least four times the mass of Earth and have orbital periods of 11.5 days and 34 days, respectively. The study also refined the mass and radius determinations for the previously discovered planet, GJ 367 b. These findings contribute to our understanding of multiplanetary systems and the formation of ultra-short-period exoplanets.
Scientists have theorized that planets made of dark matter could exist and have laid out how they could be detected. These hypothetical planets could be detected through transit data and radial velocity measurements, which could reveal anomalies in their properties that defy our current understanding of planet formation. defy our current understanding of planet formation. The researchers also suggest that the light curve of a dark matter exoplanet could be distinguishable from that of an ordinary exoplanet due to its tiny but non-vanishing interaction strength with Standard Model particles. Further study is needed to set bounds on dark matter exoplanet abundance if they are not detected.