EXOTIME

Searching for planets around pulsating subdwarf B stars

Sonja Schuh, Roberto Silvotti, Ronny Lutz, Björn Loeptien, Elizabeth M. Green, Roy H. Østensen, Silvio Leccia, Seung Lee Kim, Gilles Fontaine, Stéphane Charpinet, Myriam Francœur, Suzanna Randall, Cristina Rodríguez-López, Valerie van Grootel, Andrew P. Odell, M. Paparó, Zsófia Bognár, Péter Pápics, Thorsten Nagel, Benjamin Beeck & 10 others Markus Hundertmark, Thorsten Stahn, Stefan Dreizler, Frederic V. Hessman, Massimo Dall'Ora, Dario Mancini, Fausto Cortecchia, Serena Benatti, Riccardo Claudi, Rimvydas Janulis

Research output: Article

11 Citations (Scopus)

Abstract

In 2007, a companion with planetary mass was found around the pulsating subdwarf B star V391 Pegasi with the timing method, indicating that a previously undiscovered population of substellar companions to apparently single subdwarf B stars might exist. Following this serendipitous discovery, the EXOTIME (http://www. na. astro. it/~silvotti/exotime/) monitoring program has been set up to follow the pulsations of a number of selected rapidly pulsating subdwarf B stars on time scales of several years with two immediate observational goals: (1)determine Ṗ of the pulsational periods P (2) search for signatures of substellar companions in O-C residuals due to periodic light travel time variations, which would be tracking the central star's companion-induced wobble around the centre of mass These sets of data should therefore, at the same time, on the one hand be useful to provide extra constraints for classical asteroseismological exercises from the Ṗ (comparison with "local" evolutionary models), and on the other hand allow one to investigate the preceding evolution of a target in terms of possible "binary" evolution by extending the otherwise unsuccessful search for companions to potentially very low masses. While timing pulsations may be an observationally expensive method to search for companions, it samples a different range of orbital parameters, inaccessible through orbital photometric effects or the radial velocity method: the latter favours massive close-in companions, whereas the timing method becomes increasingly more sensitive toward wider separations. In this paper we report on the status of the on-going observations and coherence analysis for two of the currently five targets, revealing very well-behaved pulsational characteristics in HS 0444+0458, while showing HS 0702+6043 to be more complex than previously thought.

Original languageEnglish
Pages (from-to)231-242
Number of pages12
JournalAstrophysics and Space Science
Volume329
Issue number1
DOIs
Publication statusPublished - 2010

Fingerprint

subdwarf stars
B stars
planets
planet
time measurement
planetary mass
orbitals
companion stars
physical exercise
radial velocity
travel
center of mass
signatures
travel time
timescale
method
monitoring

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Schuh, S., Silvotti, R., Lutz, R., Loeptien, B., Green, E. M., Østensen, R. H., ... Janulis, R. (2010). EXOTIME: Searching for planets around pulsating subdwarf B stars. Astrophysics and Space Science, 329(1), 231-242. https://doi.org/10.1007/s10509-010-0356-4

EXOTIME : Searching for planets around pulsating subdwarf B stars. / Schuh, Sonja; Silvotti, Roberto; Lutz, Ronny; Loeptien, Björn; Green, Elizabeth M.; Østensen, Roy H.; Leccia, Silvio; Kim, Seung Lee; Fontaine, Gilles; Charpinet, Stéphane; Francœur, Myriam; Randall, Suzanna; Rodríguez-López, Cristina; van Grootel, Valerie; Odell, Andrew P.; Paparó, M.; Bognár, Zsófia; Pápics, Péter; Nagel, Thorsten; Beeck, Benjamin; Hundertmark, Markus; Stahn, Thorsten; Dreizler, Stefan; Hessman, Frederic V.; Dall'Ora, Massimo; Mancini, Dario; Cortecchia, Fausto; Benatti, Serena; Claudi, Riccardo; Janulis, Rimvydas.

In: Astrophysics and Space Science, Vol. 329, No. 1, 2010, p. 231-242.

Research output: Article

Schuh, S, Silvotti, R, Lutz, R, Loeptien, B, Green, EM, Østensen, RH, Leccia, S, Kim, SL, Fontaine, G, Charpinet, S, Francœur, M, Randall, S, Rodríguez-López, C, van Grootel, V, Odell, AP, Paparó, M, Bognár, Z, Pápics, P, Nagel, T, Beeck, B, Hundertmark, M, Stahn, T, Dreizler, S, Hessman, FV, Dall'Ora, M, Mancini, D, Cortecchia, F, Benatti, S, Claudi, R & Janulis, R 2010, 'EXOTIME: Searching for planets around pulsating subdwarf B stars', Astrophysics and Space Science, vol. 329, no. 1, pp. 231-242. https://doi.org/10.1007/s10509-010-0356-4
Schuh S, Silvotti R, Lutz R, Loeptien B, Green EM, Østensen RH et al. EXOTIME: Searching for planets around pulsating subdwarf B stars. Astrophysics and Space Science. 2010;329(1):231-242. https://doi.org/10.1007/s10509-010-0356-4
Schuh, Sonja ; Silvotti, Roberto ; Lutz, Ronny ; Loeptien, Björn ; Green, Elizabeth M. ; Østensen, Roy H. ; Leccia, Silvio ; Kim, Seung Lee ; Fontaine, Gilles ; Charpinet, Stéphane ; Francœur, Myriam ; Randall, Suzanna ; Rodríguez-López, Cristina ; van Grootel, Valerie ; Odell, Andrew P. ; Paparó, M. ; Bognár, Zsófia ; Pápics, Péter ; Nagel, Thorsten ; Beeck, Benjamin ; Hundertmark, Markus ; Stahn, Thorsten ; Dreizler, Stefan ; Hessman, Frederic V. ; Dall'Ora, Massimo ; Mancini, Dario ; Cortecchia, Fausto ; Benatti, Serena ; Claudi, Riccardo ; Janulis, Rimvydas. / EXOTIME : Searching for planets around pulsating subdwarf B stars. In: Astrophysics and Space Science. 2010 ; Vol. 329, No. 1. pp. 231-242.
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abstract = "In 2007, a companion with planetary mass was found around the pulsating subdwarf B star V391 Pegasi with the timing method, indicating that a previously undiscovered population of substellar companions to apparently single subdwarf B stars might exist. Following this serendipitous discovery, the EXOTIME (http://www. na. astro. it/~silvotti/exotime/) monitoring program has been set up to follow the pulsations of a number of selected rapidly pulsating subdwarf B stars on time scales of several years with two immediate observational goals: (1)determine Ṗ of the pulsational periods P (2) search for signatures of substellar companions in O-C residuals due to periodic light travel time variations, which would be tracking the central star's companion-induced wobble around the centre of mass These sets of data should therefore, at the same time, on the one hand be useful to provide extra constraints for classical asteroseismological exercises from the Ṗ (comparison with {"}local{"} evolutionary models), and on the other hand allow one to investigate the preceding evolution of a target in terms of possible {"}binary{"} evolution by extending the otherwise unsuccessful search for companions to potentially very low masses. While timing pulsations may be an observationally expensive method to search for companions, it samples a different range of orbital parameters, inaccessible through orbital photometric effects or the radial velocity method: the latter favours massive close-in companions, whereas the timing method becomes increasingly more sensitive toward wider separations. In this paper we report on the status of the on-going observations and coherence analysis for two of the currently five targets, revealing very well-behaved pulsational characteristics in HS 0444+0458, while showing HS 0702+6043 to be more complex than previously thought.",
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AU - Schuh, Sonja

AU - Silvotti, Roberto

AU - Lutz, Ronny

AU - Loeptien, Björn

AU - Green, Elizabeth M.

AU - Østensen, Roy H.

AU - Leccia, Silvio

AU - Kim, Seung Lee

AU - Fontaine, Gilles

AU - Charpinet, Stéphane

AU - Francœur, Myriam

AU - Randall, Suzanna

AU - Rodríguez-López, Cristina

AU - van Grootel, Valerie

AU - Odell, Andrew P.

AU - Paparó, M.

AU - Bognár, Zsófia

AU - Pápics, Péter

AU - Nagel, Thorsten

AU - Beeck, Benjamin

AU - Hundertmark, Markus

AU - Stahn, Thorsten

AU - Dreizler, Stefan

AU - Hessman, Frederic V.

AU - Dall'Ora, Massimo

AU - Mancini, Dario

AU - Cortecchia, Fausto

AU - Benatti, Serena

AU - Claudi, Riccardo

AU - Janulis, Rimvydas

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KW - Individual: HS 0702+6043

KW - Individual: HS 2201+2610

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KW - Stars: oscillations

KW - Stars: planetary systems

KW - Stars: subdwarfs

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