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Full-Text Articles in Physical Sciences and Mathematics
Collisions In A Gas-Rich White Dwarf Planetary Debris Disc, Ted Von Hippel, University College London, Scott J. Kenyon, Jay Farihi, Erik Dennihy, Boris T. Gänsicke, J.J. Hermes, Carl Melis
Collisions In A Gas-Rich White Dwarf Planetary Debris Disc, Ted Von Hippel, University College London, Scott J. Kenyon, Jay Farihi, Erik Dennihy, Boris T. Gänsicke, J.J. Hermes, Carl Melis
Publications
WD 0145+234 is a white dwarf that is accreting metals from a circumstellar disc of planetary material. It has exhibited a substantial and sustained increase in 3–5 μm flux since 2018. Follow-up Spitzer photometry reveals that emission from the disc had begun to decrease by late 2019. Stochastic brightening events superimposed on the decline in brightness suggest the liberation of dust during collisional evolution of the circumstellar solids. A simple model is used to show that the observations are indeed consistent with ongoing collisions. Rare emission lines from circumstellar gas have been detected at this system, supporting the emerging picture …
Dust Production And Depletion In Evolved Planetary Systems, J. Farihi, Ted Von Hippel, Rik Van Lieshout, P.W. Cauley, Erik Dennihy, Et Al.
Dust Production And Depletion In Evolved Planetary Systems, J. Farihi, Ted Von Hippel, Rik Van Lieshout, P.W. Cauley, Erik Dennihy, Et Al.
Publications
The infrared dust emission from the white dwarf GD 56 is found to rise and fall by 20 per cent peak-to-peak over 11.2 yr, and is consistent with ongoing dust production and depletion. It is hypothesized that the dust is produced via collisions associated with an evolving dust disc, temporarily increasing the emitting surface of warm debris, and is subsequently destroyed or assimilated within a few years. The variations are consistent with debris that does not change temperature, indicating that dust is produced and depleted within a fixed range of orbital radii. Gas produced in collisions may rapidly re-condense onto …
Observations Of Herbig Ae/Be Stars With Herschel/Pacs. The Atomic And Molecular Contents Of Their Protoplanetary Discs, G Meeus, B Montesinos, I Mendigutia, I Kamp, W F. Thi, C Eiroa, C A. Grady, G Mathews, G Sandell, C. Martin-Zaidi, Sean D. Brittain, W.R.F. Dent, C Howard, F Menard, C Pinte, A Roberge, B Vandenbussche, J P. Williams
Observations Of Herbig Ae/Be Stars With Herschel/Pacs. The Atomic And Molecular Contents Of Their Protoplanetary Discs, G Meeus, B Montesinos, I Mendigutia, I Kamp, W F. Thi, C Eiroa, C A. Grady, G Mathews, G Sandell, C. Martin-Zaidi, Sean D. Brittain, W.R.F. Dent, C Howard, F Menard, C Pinte, A Roberge, B Vandenbussche, J P. Williams
Publications
We observed a sample of 20 representative Herbig Ae/Be stars and 5 A-type debris discs with PACS onboard Herschel, as part of the GAS in Protoplanetary Systems (GASPS) project. The observations were done in spectroscopic mode, and cover the far-infrared lines of [O i], [C ii], CO, CH+, H2O, and OH. We have a [Oi] 63 μm detection rate of 100% for the Herbig Ae/Be and 0% for the debris discs. The [Oi] 145 μm line is only detected in 25% and CO J = 18–17 in 45% (and fewer cases for higher J transitions) of the Herbig Ae/Be stars, …
Detailed Abundances Of The Solar Twins 16 Cygni And B Cygni: Constraining Planet Formation Models, Simon C. Schuler, Katia Cunha, Verne V. Smith, Luan Ghezzi, Jeremy R. King, Constantine P. Deliyannis, Ann Merchant Boesgaard
Detailed Abundances Of The Solar Twins 16 Cygni And B Cygni: Constraining Planet Formation Models, Simon C. Schuler, Katia Cunha, Verne V. Smith, Luan Ghezzi, Jeremy R. King, Constantine P. Deliyannis, Ann Merchant Boesgaard
Publications
Results of a detailed abundance analysis of the solar twins 16 Cyg A and 16 Cyg B based on high-resolution, high signal-to-noise ratio echelle spectroscopy are presented. 16 Cyg B is known to host a giant planet while no planets have yet been detected around 16 Cyg A. Stellar parameters are derived directly from our high-quality spectra, and the stars are found to be physically similar, with ΔTeff = +43 K, Δ log g =−0.02 dex, and Δξ = +0.10 km s−1 (in the sense of A − B), consistent with previous findings. Abundances of 15 elements are derived and …
Abundances Of Stars With Planets: Trends With Condensation Temperature, Simon C. Schuler, Davin Flateau, Katia Cunha, Jeremy R. King, Luan Ghezzi, Verne V. Smith
Abundances Of Stars With Planets: Trends With Condensation Temperature, Simon C. Schuler, Davin Flateau, Katia Cunha, Jeremy R. King, Luan Ghezzi, Verne V. Smith
Publications
Precise abundances of 18 elements have been derived for 10 stars known to host giant planets from high signal-to-noise ratio, high-resolution echelle spectroscopy. Internal uncertainties in the derived abundances are typically 0.05 dex. The stars in our sample have all been previously shown to have abundances that correlate with the condensation temperature (Tc) of the elements in the sense of increasing abundances with increasing Tc; these trends have been interpreted as evidence that the stars may have accreted H-depleted planetary material. Our newly derived abundances also correlate positively with Tc, although slopes of linear least-square fits to the [m/H]–Tc relations …
Gas In The Protoplanetary Disc Of Hd 169142: Herschel's View, G Meeus, C Pinte, P Woitke, B Montesinos, I Mendigutia, P Riviere-Marichalar, C Eiroa, G S. Mathews, B Vandenbussche, C D. Howard, A Roberge, G Sandell, G Duchene, F Menard, C A. Grady, W.R.F. Dent, I Kamp, J C. Augereau, W F. Thi, I Tilling, J M. Alacid, S Andrews, D R. Ardila, G Aresu, D Barrado, Sean D. Brittain
Gas In The Protoplanetary Disc Of Hd 169142: Herschel's View, G Meeus, C Pinte, P Woitke, B Montesinos, I Mendigutia, P Riviere-Marichalar, C Eiroa, G S. Mathews, B Vandenbussche, C D. Howard, A Roberge, G Sandell, G Duchene, F Menard, C A. Grady, W.R.F. Dent, I Kamp, J C. Augereau, W F. Thi, I Tilling, J M. Alacid, S Andrews, D R. Ardila, G Aresu, D Barrado, Sean D. Brittain
Publications
In an effort to simultaneously study the gas and dust components of the disc surrounding the young Herbig Ae star HD 169142, we present far-IR observations obtained with the PACS instrument onboard the Herschel Space Observatory. This work is part of the open time key program GASPS, which is aimed at studying the evolution of protoplanetary discs. To constrain the gas properties in the outer disc, we observed the star at several key gas-lines, including [OI] 63.2 and 145.5 mum, [CII] 157.7 mum, CO 72.8 and 90.2 mum, and o-H2O 78.7 and 179.5 mum. We only detect the [OI] 63.2 …
Warm Gas In The Inner Disks Around Young Intermediate-Mass Stars, Sean D. Brittain, Theodore Simon, Joan R. Najita, Terrence W. Rettig
Warm Gas In The Inner Disks Around Young Intermediate-Mass Stars, Sean D. Brittain, Theodore Simon, Joan R. Najita, Terrence W. Rettig
Publications
The characterization of gas in the inner disks around young stars is of particular interest because of its connection to planet formation. In order to study the gas in inner disks, we have obtained high-resolution K- and M-band spectroscopy of 14 intermediate-mass young stars. In sources that have optically thick inner disks, i.e., E(K-L)>1, our detection rate of the rovibrational CO transitions is 100%, and the gas is thermally excited. Of the five sources that do not have optically thick inner disks, we only detect the rovibrational CO transitions from HD 141569. In this case, we show that the …