Issue |
A&A
Volume 595, November 2016
|
|
---|---|---|
Article Number | A79 | |
Number of page(s) | 8 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/201628544 | |
Published online | 01 November 2016 |
High-contrast imaging of ϵ Eridani with ground-based instruments
1 Astronomical Institute, Tohoku
University, Aoba-ku,
Sendai, 980-8578
Miyagi,
Japan
e-mail: mizuki@astr.tohoku.ac.jp
2 Institute of Space and Astronautical
Science, JAXA, 3-1-1 Yoshinodai, Sagamihara, Kanagawa
Japan
3 Department of Physics and
Astronomy, College of Charleston,
58 Coming St., Charleston, SC
29424,
USA
4 Department of Earth and Planetary
Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, 152-8551
Tokyo,
Japan
5 Astrobiology Center of NINS, 2-21-1,
Osawa, Mitaka, 181-8588
Tokyo,
Japan
6 National Astronomical Observatory of
Japan, 2-21-1, Osawa, Mitaka,
181-8588
Tokyo,
Japan
7 Department of Physics, University of
Cincinnati, Cincinnati, OH
45221-0011,
USA
8 Subaru Telescope, National
Astronomical Observatory of Japan, 650 North A’ohoku Place, Hilo, HI96720,
USA
9 Laboratoire Lagrange (UMR 7293),
Université de Nice-Sophia Antipolis, CNRS, Observatoire de la Côte
d’Azur, 28 avenue
Valrose, 06108
Nice Cedex 2,
France
10 Max Planck Institute for
Astronomy, Königstuhl
17, 69117
Heidelberg,
Germany
11 Astrophysics Department, Institute
for Advanced Study, Princeton, NJ
08540,
USA
12 Universitäts-Sternwarte München,
Ludwig-Maximilians-Universität, Scheinerstr. 1, 81679
München,
Germany
13 Exoplanets and Stellar Astrophysics
Laboratory, Code 667, Goddard Space
Flight Center, Greenbelt, MD
20771,
USA
14 Eureka Scientific,
2452 Delmer, Suite 100,
Oakland
CA96002,
USA
15 Goddard Center for
Astrobiology, USA
16 Institute for Astronomy, University
of Hawaii, 640 N. A’ohoku
Place, Hilo,
HI
96720,
USA
17 Department of Astrophysical
Science, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ08544, USA
18 Department of Astronomy, The
University of Tokyo, 7-3-1, Hongo,
Bunkyo-ku, 113-0033
Tokyo,
Japan
19 Department of Earth and Space
Science, Graduate School of Science, Osaka University, 1-1 Machikaneyamacho, Toyonaka, 560-0043
Osaka,
Japan
20 Hiroshima University,
1-3-2, Kagamiyama,
Higashihiroshima, 739-8511
Hiroshima,
Japan
21 Department of
Astrophysics, CAB-CSIC/INTA, 28850
Torrej’on de Ardoz, Madrid, Spain
22 Jet Propulsion Laboratory,
California Institute of Technology, Pasadena, CA,
171-113,
USA
23 Department of Astronomical Science,
The Graduate University for Advanced Studies, 2-21-1, Osawa, Mitaka, 181-8588
Tokyo,
Japan
24 Institute of Astronomy and
Astrophysics, Academia Sinica, PO
Box 23-141, 10617
Taipei,
Taiwan
25 Swiss Federal Institute of
Technology (ETH Zurich), Institute for Astronomy, Wolfgang-Pauli-Strasse 27, 8093
Zurich,
Switzerland
26 Kavli Institute for Physics and
Mathematics of the Universe, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, 277-8568
Chiba,
Japan
27 Department of Cosmosciences,
Hokkaido University, Kita-ku,
Sapporo, 060-0810
Hokkaido,
Japan
28 H. L. Dodge Department of Physics
and Astronomy, University of Oklahoma, 440
WBrooks St Norman, OK
73019,
USA
Received:
18
March
2016
Accepted:
23
August
2016
ϵ Eridani is one of the nearest solar-type stars. Its proximity and relatively young age allow high-contrast imaging observations to achieve sensitivities to planets at narrow separations down to an inner radius of ~5 AU. Previous observational studies of the system report a dust disk with asymmetric morphology as well as a giant planet with large orbital eccentricity, which may require another massive companion to induce the peculiar morphology and to enhance the large orbital eccentricity. In this paper, we report results from deep high-contrastimaging observations to detect the previously reported planet and search for other unseen less massive companions with Subaru/HiCIAO, Gemini-South/NICI, and VLT/NACO. No positive detection was made, but high-contrast measurements with the CH4S narrow-band filter of HiCIAO achieved sensitivities at 14.7 mag differential magnitude level, at an angular separation of 1.0″. In terms of planetary mass, as determined by cooling evolutionary models, the highest sensitivities were achieved by the Lp broad-band filter of NACO, resulting in sensitivities corresponding to 1.8, 2.8, and 4.5 Mjup at the projected separation of 3 AU, if 200, 400, and 800 Myr is assumed for the age of the system, respectively. We also discuss origins of the dust disk from the detection sensitivity in the planetary mass and find that a less massive eccentric planet is preferred for disk stirring, which is consistent with the orbital parameters of ϵ Eri b claimed from the previous long-term radial velocity monitoring.
Key words: planets and satellites: general / stars: individual:ϵEridani / instrumentation: adaptive optics / techniques: image processing
© ESO 2016
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0),
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