Newfound 'hot Jupiter' exoplanet celebrates New Year's every 5 days

[Admin]

A newly discovered hot Jupiter exoplanet located 530 light years from Earth experiences a new year every five days and has a blisteringly hot surface temperature of around 2240 degrees Fahrenheit.

Newfound 'hot Jupiter' exoplanet celebrates New Year's every 5 days : Read more

 

[rod]

"Clark and his team also found that the orbit of TOI-778 b is close to being aligned with the stellar equator of its dwarf star. They believe that the planet came to this position by sedately migrating through the disk of its host star TOI-778 rather than reaching this point via a chaotic process. "TOI-778 b joins a cohort of other hot Jupiters with well-aligned orbits, suggesting that disk migration is the likely cause of their evolution to their current positions," Clark and his co-authors remark in the paper."

That is very interesting, a hot Jupiter that *sedately* migrated inwards to its host star.

ref - Spinning up a Daze: TESS Uncovers a Hot Jupiter orbiting the Rapid-Rotator TOI-778, https://arxiv.org/abs/2212.08242, 16-Dec-2022.

My observation. Concerning disk migration scenarios to explain the origin of hot jupiters like TOI-778 b, the 18-page PDF report states: "It therefore seems most likely that TOI-778 b sedately migrated through its host’s disk, rather than reaching its current location through more chaotic means. Indeed, with a low obliquity angle and a stellar age of ~ 2 Gyr, we can rule out migration mechanisms such as high-eccentricity, planet-planet scattering, Kozai–Lidov tidal and secular chaos migrations (Masset & Papaloizou 2003; Nagasawa et al. 2008b; Dawson & Johnson 2018). Figure 9 shows the planetary obliquity as a function of host star temperature with TOI-778 b and the sample of known hot Jupiters with obliquity measurements. From Figure 9, TOI-778 b joins a cohort of other hot Jupiters with well-aligned orbits, suggesting that disk migration is the likely case of their evolution to their current positions."

My note. Properties for this hot jupiter are listed in the PDF report: "Table 3. Astrophysical parameters for TOI-778 b as derived by Allesfitter. Priors are shown as uniform U(a,b) or normal N(nu, sigma). Parameters used for the transit and radial velocity fits that are not located in this table can be found in Table 4."

My note. Exactly where TOI-778 b initially formed in the postulated, early protoplanetary disc, and how far it *sedately* migrated inwards to its present position ~ 0.06 au, I did not find shown or how long the calm migration lasted.

 

[spacejayk]

That's a great question Rod. I'm Jake, the lead author for this discovery. The short answer is, I didn't include the hypothetical migration time in the paper as there's just so much to write about and not enough time! There is a lot that needs to be considered when calculating the migration time of planets such as TOI-778 b. These considerations include hypothesising where and how far the protoplanetary disk was during TOI-778's (the star) formation, where TOI 778b was located in that disk etc. Sadly, there's no straight-forward answer, as numerous simulations would need to be done to properly estimate these properties.

However, it could be done and I would be excited by seeing the results of such a simulation Thanks again for your interest in TOI-778 b Rod!

"Clark and his team also found that the orbit of TOI-778 b is close to being aligned with the stellar equator of its dwarf star. They believe that the planet came to this position by sedately migrating through the disk of its host star TOI-778 rather than reaching this point via a chaotic process. "TOI-778 b joins a cohort of other hot Jupiters with well-aligned orbits, suggesting that disk migration is the likely cause of their evolution to their current positions," Clark and his co-authors remark in the paper."

That is very interesting, a hot Jupiter that *sedately* migrated inwards to its host star.

ref - Spinning up a Daze: TESS Uncovers a Hot Jupiter orbiting the Rapid-Rotator TOI-778, https://arxiv.org/abs/2212.08242, 16-Dec-2022.

My observation. Concerning disk migration scenarios to explain the origin of hot jupiters like TOI-778 b, the 18-page PDF report states: "It therefore seems most likely that TOI-778 b sedately migrated through its host’s disk, rather than reaching its current location through more chaotic means. Indeed, with a low obliquity angle and a stellar age of ~ 2 Gyr, we can rule out migration mechanisms such as high-eccentricity, planet-planet scattering, Kozai–Lidov tidal and secular chaos migrations (Masset & Papaloizou 2003; Nagasawa et al. 2008b; Dawson & Johnson 2018). Figure 9 shows the planetary obliquity as a function of host star temperature with TOI-778 b and the sample of known hot Jupiters with obliquity measurements. From Figure 9, TOI-778 b joins a cohort of other hot Jupiters with well-aligned orbits, suggesting that disk migration is the likely case of their evolution to their current positions."

My note. Properties for this hot jupiter are listed in the PDF report: "Table 3. Astrophysical parameters for TOI-778 b as derived by Allesfitter. Priors are shown as uniform U(a,b) or normal N(nu, sigma). Parameters used for the transit and radial velocity fits that are not located in this table can be found in Table 4."

My note. Exactly where TOI-778 b initially formed in the postulated, early protoplanetary disc, and how far it *sedately* migrated inwards to its present position ~ 0.06 au, I did not find shown or how long the calm migration lasted.

 

[rod]

That's a great question Rod. I'm Jake, the lead author for this discovery. The short answer is, I didn't include the hypothetical migration time in the paper as there's just so much to write about and not enough time! There is a lot that needs to be considered when calculating the migration time of planets such as TOI-778 b. These considerations include hypothesising where and how far the protoplanetary disk was during TOI-778's (the star) formation, where TOI 778b was located in that disk etc. Sadly, there's no straight-forward answer, as numerous simulations would need to be done to properly estimate these properties.

However, it could be done and I would be excited by seeing the results of such a simulation Thanks again for your interest in TOI-778 b Rod!

I love exoplanet studies and use these two sites for exoplanets and properties. MS ACCESS DB, reports and MS Excel stats too.

The Extrasolar Planets Encyclopaedia (exoplanet.eu)

NASA Exoplanet Archive (caltech.edu)