English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The star gamma Cep is known as a single-lined spectroscopic triple system ata distance of 13.8 pc, composed of a K1 III-IV primary star with V = 3.2 mag, astellar-mass companion in a 66--67 year orbit (Torres 2006), and a substellarcompanion with M_p sin i = 1.7 M_Jup that is most likely a planet (Hatzes etal. 2003). We aim to obtain a first direct detection of the stellar companion,to determine its current orbital position (for comparison with thespectroscopic and astrometric data), its infrared magnitude and, hence, mass.We use the Adaptive Optics camera CIAO at the Japanese 8m telescope Subaru onMauna Kea, Hawaii, with the semi-transparent coronograph to block most of thelight from the bright primary gamma Cep A, and to detect at the same time thefaint companion B. In addition, we also used the IR camera Omega-Cass at theCalar Alto 3.5m telescope, Spain, to image gamma Cep A and B by adding up manyvery short integrations (without AO). gamma Cep B is clearly detected on ourCIAO and Omega-Cass images. We use a photometric standard star to determine themagnitude of B after PSF subtraction in the Subaru image, and the magnitudedifference between A and B in the Calar Alto images, and find an average valueof K = 7.3 \pm 0.2 mag. The separations and position angles between A and B aremeasured on 15 July 2006 and 11 and 12 Sept 2006, B is slightly south of westof A. By combining the radial velocity, astrometric, and imaging data, we haverefined the binary orbit and determined the dynamical masses of the two starsin the gamma Cep system, namely 1.40 \pm 0.12 M_sun for the primary and 0.409\pm 0.018 M_sun for the secondary (consistent with being a M4 dwarf). We alsodetermine the minimum mass of the sub-stellar companion to be M_p sin i = 1.60\pm 0.13 M_Jup.Comment: A&A in press, 5 pages with 4 figure

Direct detection of exoplanet host star companionγCep B and revised masses for both stars and the sub-stellar object