First Gaia astrometric and RV planet candidates

You can find them at http://exoplanet.eu/catalog/ . Click on "status:candidates" upper link: "status:candidates". 63 are astrometric detections and 9 are from radial velocities.

The great majority got mass beyond even Brown Dwarfs, why they consider it planets candidates? It’s seems more like stellar candidates. I’ve counted just about 9 to 10 which is the planet candidate mass regime.

Was I responsible for EPE updates, I would probably be rather “generous” in considering certain brown dwarfs up to the 70 M_J mass limit as “planets”, but lately EPE seems like being updated by someone that is not expert at all. So have I noticed the Gaia candidates in “candidate” section and I thought of a mistype or something similar at first. Let alone the tens, if not hundreds of confirmed K2, Kepler, TESS exoplanets still not listed since last year or more. I honestly do not understand. Unless there is an imminent update about circumbinary planets but I don’t think this is the case.

This is an error on exoplanet.eu's end. I calculated masses for these planets on my own and got quite different values -- usually 6 - 12 Jupiter-masses, but still traditionally planetary. The values I got for their inclinations and ascending nodes don't match either.

I wonder who’s updating EPE webpages lately.
Additionally the latest update (apologies for the OT) is about a transiting exomoon candidate to binary rogue planet 2MASS J1119-1137 the authors themselves consider tentative, not conclusive detection.

Daniel wrote:

The great majority got mass beyond even Brown Dwarfs, why they consider it planets candidates? It’s seems more like stellar candidates. I’ve counted just about 9 to 10 which is the planet candidate mass regime.

To "Daniel":

It looks indeed strange that the masses go much above 80 Jupiter mass.

But note that:
- these are only candidates
- it is a sublist of candidates provided by Gaia:
https://www.cosmos.esa.int/web/gaia/exoplanets
- when you look at the error bars for each individual planets
you see that for all of them M-1 sigma < 20 Jupiter mass
- it apparently comes from a collaboration between
the Gaia DPAC team and the EPE team: 26 July News at the EPE.
It thus looks endorsed by Gaia.

Sirius_Alpha wrote:

This is an error on exoplanet.eu's end. I calculated masses for these planets on my own and got quite different values -- usually 6 - 12 Jupiter-masses, but still traditionally planetary. The values I got for their inclinations and ascending nodes don't match either.

Interesting.
Could you post the list of your planet masses calculations ?

The Gaia Archive has the masses for the systems in the table gaiadr3.binary_masses (in the Performance Verification section of the Gaia DR3 tables).

E.g. taking Gaia-ASOI-049, which has DR3 identifier Gaia DR3 1462767459023424512.

ADQL:

Code:

SELECT * FROM gaiadr3.binary_masses WHERE source_id = 1462767459023424512

The mass of the secondary (using Google for the Msun-Mjup conversion):

m2: <blank>
m2_lower: 0.0059425305 M_sun (=6.23 M_J)
m2_upper: 0.31503138 M_sun (=330.12 M_J)

Which looks pretty much like what EPE has if you use (m2_lower+m2_upper)/2 for the mass estimate and set the error bars to touch the limits.

But isn’t it a little “useless” to list these Gaia candidates despite such uncertain mass limits? Even an average value (with reference to Gaia-ASOI-49) points to stellar domain, in this case 168 M_J. Unless more robust constraints are provided in a near future what’s the point to mention them?

I just took the K_ast from the two-body solutions. In the case of Gaia-ASOI-49, K_ast = 0.374995 mas, gives you a mass of ~6.3 Jupiter-masses taking the period and stellar mass into account. Unfortunately it didn't seem to come with error bars. So I have no idea where the m2_upper value comes from.

Some updates for known and some new exoplanet/BD systems

The Masses of a Sample of Radial-Velocity Exoplanets with Astrometric Measurements

Quote :

Being one of the most fundamental physical parameter of astronomical objects, mass plays a vital role in the study of exoplanets, including their temperature structure, chemical composition, formation, and evolution. However, nearly a quarter of the known confirmed exoplanets lack measurements of their masses. This is particularly severe for those discovered via the radial-velocity (RV) technique, which alone could only yield the minimum mass of planets. In this study, we use published RV data combined with astrometric data from a cross-calibrated Hipparcos-Gaia Catalog of Accelerations (HGCA) to jointly constrain the masses of 115 RV-detected substellar companions, by conducting full orbital fits using the public tool orvara. Among them, 9 exoplanets with Mpsini<13.5 M_Jup are reclassified to the brown dwarf (BD) regime, and 16 BD candidates (13.5⩽Mpsini<80M_Jup) turn out to be low-mass M dwarfs. We point out the presence of a transition in the BD regime as seen in the distributions of host star metallicity and orbital eccentricity with respect to planet masses. We confirm the previous findings that companions with masses below 42.5 M_Jup might primarily form in the protoplanetary disc through core accretion or disc gravitational instability, while those with masses above 42.5 MJup formed through the gravitational instability of molecular cloud like stars. Selection effects and detection biases which may affect our analysis to some extent, are discussed.

1) Formerly unconfirmed planets at HD 167677 and HD 89839 are confirmed and EPE added them to the list.

2) HD 165131 b and HD 62364 b are new entries as either massive Jovian planets or low-mass brown dwarfs, the latter also detected by Feng et al. (2022) along with a second companion, hence making up a multi-planet system.

3) Several confirmed planets: GJ 832 b, HD 50554 b... *just check Table A.5, I'm lazy*  


4) Planets turning into BDs (or just "getting heavier"): HD 14067 b (14.9 M_Jup), HD 23596 Ab (14.6 M_Jup), HD 217786 Ab (28.3 M_Jup), HD 139357 b (18.2 M_Jup), HIP 67537 b (13.7 M_Jup) and HIP 84056 (=HD 155233) b (from 2.6 up to 31.9 M_Jup). The only one "losing weight" is HD 136118 b (from 42 down to 16.5 M_Jup).

5) Confirmed BDs/massive planets: BD+631405 b (10.4 M_Jup), HD 14348 b (55.5 M_Jup), HD 23965 b (43.4 M_Jup), HD 30246 b (51.8 M_Jup), HD 30501 b (67.3 M_Jup), HD 74014 b (62 M_Jup), HD 122562 b (37 M_Jup), HD 125390 b (34 M_Jup), HD 175679 b (59 M_Jup), HD 214823 b (22 M_Jup), HIP 97233 b (22.6 M_Jup), HIP 106006 (=HD 204313) (19.9 M_Jup).

6) From planets... to stars: HD 203473 b (from 7.8 to 116 M_Jup), HD 283668 b (from to 53 to 319 M_Jup), HD 184601 b (from 60.27 to 117 M_Jup). The latter two were not listed at EPE, but he former one is along with HD 3277 b, it too proved to be a low-mass star.