Possible detection of two giant extrasolar planets orbiting the eclipsing polar UZ Fornacis

被引：58

作者：

Potter, Stephen B. ^{[1
]}

Romero-Colmenero, Encarni ^{[1
]}

Ramsay, Gavin ^{[2
,3
]}

Crawford, Steven ^{[1
]}

Gulbis, Amanda ^{[1
]}

Barway, Sudhanshu ^{[1
]}

Zietsman, Ewald ^{[1
,4
]}

Kotze, Marissa ^{[1
,5
]}

Buckley, David A. H. ^{[1
]}

O'Donoghue, Darragh ^{[1
]}

Siegmund, O. H. W. ^{[6
]}

McPhate, J. ^{[6
]}

Welsh, B. Y. ^{[6
]}

Vallerga, John ^{[6
]}

机构：

[1] S African Astron Observ, Cape Town, South Africa

[2] Armagh Observ, Armagh BT61 9DG, North Ireland

[3] Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England

[4] Univ S Africa, Dept Math Sci, ZA-0003 Unisa, South Africa

[5] Univ Cape Town, Dept Astron, Astrophys Cosmol & Grav Ctr ACGC, ZA-7701 Rondebosch, South Africa

[6] Univ Calif Berkeley, Space Sci Lab, Expt Astrophys Grp, Berkeley, CA 94720 USA

来源：

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | 2011年 / 416卷 / 03期

基金：

美国国家科学基金会; 新加坡国家研究基金会;

关键词：

accretion; accretion discs; methods: analytical; binaries: close; novae; cataclysmic variables; planetary systems; X-rays: stars; AM-HERCULIS SYSTEM; X-RAY BINARIES; CIRCULAR POLARIMETRY; ACCRETION STREAM; LIGHT CURVES; VV-PUPPIS; HU AQR; DP LEO; EXO-033319-2554.2; TELESCOPE;

D O I：

10.1111/j.1365-2966.2011.19198.x

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present new high-speed, multi-observatory, multi-instrument photometry of the eclipsing polar UZ For in order to measure precise mid-eclipse times with the aim of detecting any orbital period variations. When combined with published eclipse times and archival data spanning similar to 27 years, we detect departures from a linear and quadratic trend of similar to 60 s. The departures are strongly suggestive of two cyclic variations of 16(3) and 5.25(25) years. The two favoured mechanisms to drive the periodicities are either two giant extrasolar planets as companions to the binary [with minimum masses of 6.3(1.5) and 7.7(1.2) M-Jup) or a magnetic cycle mechanism (e.g. Applegate's mechanism) of the secondary star. Applegate's mechanism would require the entire radiant energy output of the secondary and would therefore seem to be the least likely of the two, barring any further refinements in the effect of magnetic fields (e.g. those of Lanza et al.). The two-planet model can provide realistic solutions but it does not quite capture all of the eclipse times measurements. A highly eccentric orbit for the outer planet would fit the data nicely, but we find that such a solution would be unstable. It is also possible that the periodicities are driven by some combination of both mechanisms. Further observations of this system are encouraged.

引用

页码：2202 / 2211

页数：10

共 43 条

[1] ORBITAL EVOLUTION OF A SINGLY CONDENSED, CLOSE BINARY, BY MASS-LOSS FROM PRIMARY AND BY ACCRETION DRAG ON CONDENSED MEMBER [J].