08-30-2019, 09:51 PM
(This post was last modified: 08-30-2019, 09:55 PM by The Astronomer.)
HR 5183 b, a cold eccentric Jupiter
On 26 August 2019, there was an announcement of the discovery of not another boring temperate terrestrial planet around a red dwarf, but a gas giant in a wide, eccentric orbit around a sunlike star. Here is Caltech's article on the planet.
This planet, known as HR 5183 b has the following properties:
HR 5183 b
Semi-major axis: 18 AU, give 6 or take 4.
Orbital period: 74 years, give 43 to take 22.
Eccentricity: 0.84
Minimum mass: 3 Jupiters
This eccentricity implies a violent encounter with another gas giant in this system. Where that gas giant is currently at is unknown, but probably outside the HR 5183 system.
While this is not the first eccentric Jupiter discovered, this is the first one found in such a large orbit. Its orbit takes it as close to its G0V type star as 3 AU, and as far away as 33 AU. I believe there is still a possibility of an Earthlike world in this system, but it would probably be quite disturbed by the gravitation effects from this large world.
Evidence of an exo-Io in orbit around WASP-49b
Link
WASP-49b is known to have extensive sodium envelope, far from the planet's surface enough to rule out the 'sodium's coming out of the planet' option. There are several other options, but one of them is the possibility of a satellite with extensive volcanic activities, similar to Io. At this point, more data is required to determine whether if this is really a moon or not. This potential moon, WASP-49b I, would compete with Kepler-1625b's Neptune-sized planet-satellite for the first confirmation of an exomoon.
WASP-49b
Semi-major axis: 0.0378 AU
Orbital period: 2.7817387
Mass: 0.378 Jupiters (120.2 Earths)
Radius: 1.115 Jupiters
On 26 August 2019, there was an announcement of the discovery of not another boring temperate terrestrial planet around a red dwarf, but a gas giant in a wide, eccentric orbit around a sunlike star. Here is Caltech's article on the planet.
This planet, known as HR 5183 b has the following properties:
HR 5183 b
Semi-major axis: 18 AU, give 6 or take 4.
Orbital period: 74 years, give 43 to take 22.
Eccentricity: 0.84
Minimum mass: 3 Jupiters
This eccentricity implies a violent encounter with another gas giant in this system. Where that gas giant is currently at is unknown, but probably outside the HR 5183 system.
While this is not the first eccentric Jupiter discovered, this is the first one found in such a large orbit. Its orbit takes it as close to its G0V type star as 3 AU, and as far away as 33 AU. I believe there is still a possibility of an Earthlike world in this system, but it would probably be quite disturbed by the gravitation effects from this large world.
Evidence of an exo-Io in orbit around WASP-49b
Link
WASP-49b is known to have extensive sodium envelope, far from the planet's surface enough to rule out the 'sodium's coming out of the planet' option. There are several other options, but one of them is the possibility of a satellite with extensive volcanic activities, similar to Io. At this point, more data is required to determine whether if this is really a moon or not. This potential moon, WASP-49b I, would compete with Kepler-1625b's Neptune-sized planet-satellite for the first confirmation of an exomoon.
WASP-49b
Semi-major axis: 0.0378 AU
Orbital period: 2.7817387
Mass: 0.378 Jupiters (120.2 Earths)
Radius: 1.115 Jupiters