SPHERE dynamical and spectroscopic characterization of HD142527B. (arXiv:1812.07814v1 [astro-ph.SR])

SPHERE dynamical and spectroscopic characterization of HD142527B. (arXiv:1812.07814v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Claudi_R/0/1/0/all/0/1">R. Claudi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Maire_A/0/1/0/all/0/1">A.-L. Maire</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mesa_D/0/1/0/all/0/1">D. Mesa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cheetham_A/0/1/0/all/0/1">A. Cheetham</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fontanive_C/0/1/0/all/0/1">C. Fontanive</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gratton_R/0/1/0/all/0/1">R. Gratton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zurlo_A/0/1/0/all/0/1">A. Zurlo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Avenhaus_H/0/1/0/all/0/1">H. Avenhaus</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bhowmik_T/0/1/0/all/0/1">T. Bhowmik</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Biller_B/0/1/0/all/0/1">B. Biller</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Boccaletti_A/0/1/0/all/0/1">A. Boccaletti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bonavita_M/0/1/0/all/0/1">M. Bonavita</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bonnefoy_M/0/1/0/all/0/1">M. Bonnefoy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cascone_E/0/1/0/all/0/1">E. Cascone</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chauvin_G/0/1/0/all/0/1">G. Chauvin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Delboulbe_A/0/1/0/all/0/1">A. Delboulbè</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Desidera_S/0/1/0/all/0/1">S. Desidera</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+DOrazi_V/0/1/0/all/0/1">V. D'Orazi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Feautrier_P/0/1/0/all/0/1">P. Feautrier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Feldt_M/0/1/0/all/0/1">M. Feldt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dotti_F/0/1/0/all/0/1">F. Flammini Dotti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Girard_J/0/1/0/all/0/1">J.H. Girard</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Giro_E/0/1/0/all/0/1">E. Giro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Janson_M/0/1/0/all/0/1">M. Janson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hagelberg_J/0/1/0/all/0/1">J. Hagelberg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Keppler_M/0/1/0/all/0/1">M. Keppler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kopytova_T/0/1/0/all/0/1">T. Kopytova</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lacour_S/0/1/0/all/0/1">S. Lacour</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lagrange_A/0/1/0/all/0/1">A.-M. Lagrange</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Langlois_M/0/1/0/all/0/1">M. Langlois</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lannier_J/0/1/0/all/0/1">J. Lannier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Coroller_H/0/1/0/all/0/1">H. Le Coroller</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Menard_F/0/1/0/all/0/1">F. Menard</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Messina_S/0/1/0/all/0/1">S. Messina</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Meyer_M/0/1/0/all/0/1">M. Meyer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Millward_M/0/1/0/all/0/1">M. Millward</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Olofsson_J/0/1/0/all/0/1">J. Olofsson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pavlov_A/0/1/0/all/0/1">A. Pavlov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Peretti_S/0/1/0/all/0/1">S. Peretti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Perrot_C/0/1/0/all/0/1">C. Perrot</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pinte_C/0/1/0/all/0/1">C. Pinte</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pragt_J/0/1/0/all/0/1">J. Pragt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ramos_J/0/1/0/all/0/1">J. Ramos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rochat_S/0/1/0/all/0/1">S. Rochat</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rodet_L/0/1/0/all/0/1">L. Rodet</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Roelfsema_R/0/1/0/all/0/1">R. Roelfsema</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rouan_D/0/1/0/all/0/1">D. Rouan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Salter_G/0/1/0/all/0/1">G. Salter</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schmidt_T/0/1/0/all/0/1">T. Schmidt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sissa_E/0/1/0/all/0/1">E. Sissa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Thebault_P/0/1/0/all/0/1">P. Thebault</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Udry_S/0/1/0/all/0/1">S. Udry</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vigan_A/0/1/0/all/0/1">A. Vigan</a>

We detect the accreting low-mass companion HD142527B at a separation of 73
mas (11.4 au) from the star. No other companions with mass greater than 10 MJ
are visible in the field of view of IFS (sim 100 au centered on the star) or
in the IRDIS field of view (sim 400 au centered on the star). Measurements
from IFS, SAM IFS, and IRDIS suggest an M6 spectral type for HD142527B, with an
uncertainty of one spectral subtype, compatible with an object of M=0.11 pm
0.06 MSun and R=0.15 pm 0.07 RSun. The determination of the mass remains a
challenge using contemporary evolutionary models, as they do not account for
the energy input due to accretion from infalling material. We consider that the
spectral type of the secondary may also be earlier than the type we derived
from IFS spectra. From dynamical considerations, we further constrain the mass
to 0.26^{+0.16}_{-0.14} MSun , which is consistent with both our spectroscopic
analysis and the values reported in the literature. Following previous methods,
the lower and upper dynamical mass values correspond to a spectral type between
M2.5 and M5.5 for the companion. By fitting the astrometric points, we find the
following orbital parameters: a period of P=35-137 yr; an inclination of
i=121-130 deg.; , a value of Omega=124-135 deg for the longitude of node, and
an 68% confidence interval of sim 18 – 57 au for the separation at periapsis.
Eccentricity and time at periapsis passage exhibit two groups of values:
sim0.2-0.45 and sim0.45-0.7 for e, and sim 2015-2020 and sim2020-2022 for
T_0. While these orbital parameters might at first suggest that HD142527B is
not the companion responsible for the outer disk truncation, a previous
hydrodynamical analysis of this system showed that they are compatible with a
companion that is able to produce the large cavity and other observed features.

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