HD 169142 - Interacting planets forming in a disk?

View previous topic View next topic Go down

HD 169142 - Interacting planets forming in a disk?

Post by Sirius_Alpha on 5th August 2014, 8:50 pm

An Enigmatic Pointlike Feature within the HD 169142 Transitional Disk
http://arxiv.org/abs/1408.0794

We report the detection of a faint pointlike feature possibly related to ongoing planet-formation in the disk of the transition disk star HD 169142. The pointlike feature has a Δ mag(L)∼ 6.4, at a separation of ∼ 0.11" and PA∼ 0 ∘ . Given its lack of an H or K S counterpart despite its relative brightness, this candidate cannot be explained by purely photospheric emission and must be a disk feature heated by an as yet unknown source. Its extremely red colors make it highly unlikely to be a background object, but future multi-wavelength followup is necessary for confirmation and characterization of this feature.

Discovery of a Companion Candidate in the HD169142 Transition Disk and the Possibility of Multiple Planet Formation
http://arxiv.org/abs/1408.0813

We present L' and J-band high-contrast observations of HD169142, obtained with the VLT/NACO AGPM vector vortex coronagraph and the Gemini Planet Imager, respectively. A source located at 0".156+/-0".032 north of the host star (PA=7.4+/-11.3 degrees) appears in the final reduced L' image. At the distance of the star (~145 pc), this angular separation corresponds to a physical separation of 22.7+/-4.7 AU, locating the source within the recently resolved inner cavity of the transition disk. The source has a brightness of L'=12.2+/-0.5 mag, whereas it is not detected in the J band (J>13.8 mag). If its L' brightness arose solely from the photosphere of a companion and given the J-L' color constraints, it would correspond to a 28-32 MJupiter object at the age of the star, according to the COND models. Ongoing accretion activity of the star suggests, however, that gas is left in the inner disk cavity from which the companion could also be accreting. In this case the object could be lower in mass and its luminosity enhanced by the accretion process and by a circumplanetary disk. A lower mass object is more consistent with the observed cavity width. Finally, the observations enable us to place an upper limit on the L'-band flux of a second companion candidate orbiting in the disk annular gap at ~50 AU, as suggested by millimeter observations. If the second companion is also confirmed, HD169142 might be forming a planetary system, with at least two companions opening gaps and possibly interacting with each other.

_________________
Caps Lock: Cruise control for 'Cool'!
avatar
Sirius_Alpha
Admin
Admin

Number of posts : 3468
Location : Earth
Registration date : 2008-04-06

View user profile http://solar-flux.forumandco.com/

Back to top Go down

Re: HD 169142 - Interacting planets forming in a disk?

Post by Stalker on 10th August 2014, 2:36 pm

Is this the same object?

_________________
avatar
Stalker
Jovian
Jovian

Number of posts : 526
Age : 26
Location : Paris, France
Registration date : 2008-06-16

View user profile http://exoplanetes.wetpaint.com/

Back to top Go down

Re: HD 169142 - Interacting planets forming in a disk?

Post by Shellface on 10th August 2014, 4:26 pm

Both papers are primarily about the same object, yes.

Shellface
Neptune-Mass
Neptune-Mass

Number of posts : 282
Location : g2 17.∞ 997 t
Registration date : 2013-02-14

View user profile

Back to top Go down

Re: HD 169142 - Interacting planets forming in a disk?

Post by Shellface on 3rd November 2014, 11:53 am

Since it's highly relevant:

Variability of Disk Emission in Pre-Main Sequence and Related Stars. III. Exploring Structural Changes in the Pre-transitional Disk in HD 169142
We present near-IR and far-UV observations of the pre-transitional (gapped) disk in HD 169142 using NASA's Infrared Telescope Facility and Hubble Space Telescope. The combination of our data along with existing data sets into the broadband spectral energy distribution reveals variability of up to 45% between ~1.5-10 μm over a maximum timescale of 10 years. All observations known to us separate into two distinct states corresponding to a high near-IR state in the pre-2000 epoch and a low state in the post-2000 epoch, indicating activity within the <1 AU region of the disk. Through analysis of the Pa β and Br γ lines in our data we derive a mass accretion rate in May 2013 of (1.5 - 2.7) x 10^-9 Msun/yr. We present a theoretical modeling analysis of the disk in HD 169142 using Monte-Carlo radiative transfer simulation software to explore the conditions and perhaps signs of planetary formation in our collection of 24 years of observations. We find that shifting the outer edge (r = 0.3 AU) of the inner disk by 0.05 AU toward the star (in simulation of accretion and/or sculpting by forming planets) successfully reproduces the shift in NIR flux. We establish that the ~40-70 AU dark ring imaged in the NIR by Quanz et al. (2013) and Momose et al. (2013) and at 7 mm by Osorio et al. (2014) may be reproduced with a 30% scaled density profile throughout the region, strengthening the link to this structure being dynamically cleared by one or more planetary mass bodies.

This paper is an extensive study of this system's disks, of which the innermost has shown significant changes in character on the timescale of a few decades.

The outer system has been characterised as an extensive disk with a cavity within 25 AU and a peculiar gap between 40 and 70 AU which is here identified as a region of decreased density. The inner gap is consistent with the position of the previously identified planet candidate (~20 AU), while the outer gap contains (at ~50 AU) a bright feature which was identified as a possible protoplanet in its discovery paper (Osorio et al. (2014)). While the changes in the inner disk are consistent with actions related to accretion by the star, There is nevertheless a large region (0.3 - 20 AU) that is cleared of material which has not yet been studied.

Shellface
Neptune-Mass
Neptune-Mass

Number of posts : 282
Location : g2 17.∞ 997 t
Registration date : 2013-02-14

View user profile

Back to top Go down

Re: HD 169142 - Interacting planets forming in a disk?

Post by Led_Zep on 10th February 2017, 8:53 pm

https://arxiv.org/abs/1702.02844

ALMA unveils rings and gaps in the protoplanetary system HD 169142: signatures of two giant protoplanets
avatar
Led_Zep
Jovian
Jovian

Number of posts : 517
Location : France
Registration date : 2011-09-09

View user profile

Back to top Go down

Re: HD 169142 - Interacting planets forming in a disk?

Post by Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum