TESS Captures Elusive Transit Signal (Image Credits: Unsplash)
864 light-years away, researchers confirmed NGTS-38 b, a super-Jupiter exoplanet nearly five times Jupiter’s mass, transiting a bright metal-rich star and expanding knowledge of distant planetary architectures.[1][2]
TESS Captures Elusive Transit Signal
The discovery began with NASA’s Transiting Exoplanet Survey Satellite, which detected a single transit of NGTS-38 b during Sector 33 observations in December 2020. This initial signal prompted an extensive follow-up campaign. Astronomers from Queen’s University Belfast, led by Toby Rodel, coordinated photometric monitoring with the Next Generation Transit Survey over 228 nights, capturing a partial transit egress.[1]
Spectroscopic observations using the CORALIE spectrograph and High Accuracy Radial Velocity Planet Searcher further refined the orbital parameters and confirmed the companion’s planetary mass. These efforts yielded one of only 13 transiting planets with periods exceeding 100 days identified by TESS, highlighting the rarity of such detections.[3]
Physical Profile of a Planetary Giant
NGTS-38 b measures 1.081 Jupiter radii in size but packs 4.78 Jupiter masses, resulting in a density of 4.69 grams per cubic centimeter. The exoplanet follows an eccentric orbit with a period of 180.53 days at an average distance of 0.7 astronomical units from its star. Its equilibrium temperature stands at 458 Kelvin, classifying it as a warm Jupiter.[2]
These traits position NGTS-38 b among well-characterized transiting warm Jupiters, though its atmosphere likely harbors molecular nitrogen absent in hotter counterparts. Current instruments limit detailed spectroscopic analysis of its gaseous envelope.
| Property | NGTS-38 b | Jupiter |
|---|---|---|
| Mass | 4.78 MJup | 1 MJup |
| Radius | 1.08 RJup | 1 RJup |
| Orbital Period | 180.5 days | 11.86 years |
| Equilibrium Temp. | 458 K | ~124 K |
A Metal-Rich Host Star Illuminates the System
The parent star, TIC-65910228 or NGTS-38, shines at visual magnitude 10.23, making it accessible for ground-based study. Classified as F6V-F7V, it boasts 1.46 solar masses, nearly twice the Sun’s radius, and an effective temperature of 6,310 Kelvin. Its metallicity reaches [Fe/H] = 0.33, marking it as metal-rich, with an estimated age of 2.2 billion years.[1]
This youthful, luminous host enhances prospects for deeper investigations. The wide orbital separation of NGTS-38 b suggests room for undetected inner planets on stable paths.
Unlocking Broader Exoplanet Insights
The find challenges detection biases toward short-period giants, as NGTS-38 b represents a longest-period transiting world from TESS data. Its eccentricity of 0.308 hints at dynamical interactions within the system. Researchers anticipate exomoons or ring systems, given the planet’s isolation.[2]
Lying in the PLATO mission’s LOPS2 field, the system promises refined parameters and possible additional companions. For details, see the study on arXiv.[2]
Key Takeaways
- NGTS-38 b’s 180-day orbit marks it as a rare long-period transiter from TESS.
- Its super-Jupiter mass and cool temperature offer a window into warm giant atmospheres.
- Future missions like PLATO could reveal inner planets, moons, or rings.
This discovery underscores the diversity of exoplanetary systems and invites ongoing scrutiny – what hidden worlds might accompany NGTS-38 b? What do you think about this find? Tell us in the comments.
