Planet PZ Tel b?

The Gemini NICI Planet-Finding Campaign: Discovery of a Close Substellar Companion to the Young Debris Disk Star PZ Tel

Quote :

We report the discovery of a tight substellar companion to the young solar analog PZ Tel, a member of the Beta Pictoris moving group observed with high contrast adaptive optics imaging as part of the Gemini NICI Planet-Finding Campaign. The companion was detected at a projected separation of 16.4 +/- 1.0 AU (0.33 +/- 0.01") in April 2009. Second-epoch observations in May 2010 demonstrate that the companion is physically associated and shows significant orbital motion. Monte Carlo modeling constrains the orbit of PZ Tel B to eccentricities > 0.6. The near-IR colors of PZ Tel B indicate a spectral type of M7+/-2 and thus this object will be a new benchmark companion for studies of ultracool, low-gravity photospheres. Adopting an age of 12 +8 -4 Myr for the system, we estimate a mass of 36 +/- 6 Mjup based on the Lyon/DUSTY evolutionary models. PZ Tel B is one of few young substellar companions directly imaged at orbital separations similar to those of giant planets in our own solar system. Additionally, the primary star PZ Tel A shows a 70 um emission excess, evidence for a significant quantity of circumstellar dust that has not been disrupted by the orbital motion of the companion.

Previously, in Extreme Solar Systems II, a suggestion that PZ Tel B might have a mass in the gas giant domain...

Now on arXiv, updated age and abundance estimates for the PZ Tel system. Estimated mass of the companion is increased, putting it firmly within the brown dwarf regime.

Well, I would like to know more from an official paper coming from ESSII.

Wiht 21 Mj mass estimate, PZ Tel b could be added to imaged planets' count. That would be the first exoplanet in Telescopium field.

First spectroscopic observations of the sub-stellar companion of the young debris disk star PZ Telescopii

Quote :

In 2010 a sub-stellar companion to the solar analog pre-main sequence star PZ Tel and member of the about 12 Myr old Beta Pic moving group was found by high-contrast direct imaging independently by two teams. In order to determine the basic parameters of this companion more precisely and independent of evolutionary models, hence age independent, we obtained follow-up spectroscopic observations of primary and companion. We use the Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) at the Very Large Telescope Unit 4/YEPUN of ESO's Paranal Observatory in H+K band and process the data using the spectral deconvolution technique. The resulting spectrum of the companion is then compared to a grid of Drift-Phoenix synthetic model spectra, a combination of a general-purpose model atmosphere code with a non-equilibrium, stationary cloud and dust model, using a chi^2 minimization analysis. We find a best fitting spectral type of G6.5 for PZ Tel A. The extracted spectrum of the sub-stellar companion, at a spatial position compatible with earlier orbit estimates, yields a temperature Teff= 2500 +138-115 K, a visual extinction A_V= 0.53 +0.84-0.53 mag, a surface gravity of log g= 3.50 +0.51-0.30 dex, and a metallicity at the edge of the grid of [M/H]= 0.30 -0.30 dex. We derive a luminosity of log(Lbol/Lsun)= -2.66 +0.06-0.08, a radius of R= 2.42 +0.28-0.34 R_Jup and a mass of M= 7.5 +16.9-4.3 M_Jup for the PZ Tel companion, being consistent with most earlier estimates using photometry alone. Combining our results with evolutionary models, we find a best fitting mass of about 21 Jupiter masses at an age corresponding to the recently determined lithium depletion age of 7 +4-2 Myr. Hence, the PZ Tel companion is most likely a wide brown dwarf companion in the 12 +8-4 Myr old Beta Pic moving group.

Emphasis mine.

I've aggregated together a few of the loose PZ Tel threads running around to keep the information more organised.

Sirius_Alpha wrote:

I've aggregated together a few of the loose PZ Tel threads running around to keep the information more organised.

Good idea, Sirius. I did not remember there was an open thread.   

Added to planet count PZ Tel b too. Should we remove the question mark from topic title?

http://exoplanet.eu/catalog/pz_tel_b/

Seems reasonable.

Finally some updates for this system

Dynamical Mass of the Young Brown Dwarf Companion PZ Tel B

Quote :

Dynamical masses of giant planets and brown dwarfs are critical tools for empirically validating substellar evolutionary models and their underlying assumptions. We present a measurement of the dynamical mass and an updated orbit of PZ Tel B, a young brown dwarf companion orbiting a late-G member of the β Pic moving group. PZ Tel A exhibits an astrometric acceleration between Hipparcos and Gaia EDR3, which enables the direct determination of the companion's mass. We have also acquired new Keck/NIRC2 adaptive optics imaging of the system, which increases the total baseline of relative astrometry to 15 years. Our joint orbit fit yields a dynamical mass of 27⁺²⁵₋₉M_Jup, semi-major axis of 27⁺¹⁴₋₄au, eccentricity of 0.52^+0.08_−0.10, and inclination of 91.73^+0.36_−0.32∘. The companion's mass is consistent within 1.1σ of predictions from four grids of hot-start evolutionary models. The joint orbit fit also indicates a more modest eccentricity of PZ Tel B than previous results. PZ Tel joins a small number of young (<200Myr) systems with benchmark substellar companions that have dynamical masses and precise ages from moving group membership.