Detection of an extraordinarily large magnetic field in the unique ultra-cool Ap star HD154708

被引：69

作者：

Hubrig, S

Nesvacil, N

Schöller, M

North, P

Mathys, G

Kurtz, DW

Wolff, B

Szeifert, T

Cunha, MS

Elkin, VG

机构：

[1] European So Observ, Santiago 19, Chile

[2] Univ Vienna, Dept Astron, A-1180 Vienna, Austria

[3] Ecole Polytech Fed Lausanne, Astrophys Lab, CH-1290 Sauverny, Switzerland

[4] Univ Cent Lancashire, Ctr Astrophys, Preston PR1 2HE, Lancs, England

[5] European So Observ, D-85748 Garching, Germany

[6] Univ Porto, Ctr Astrofis, P-4150 Oporto, Portugal

来源：

ASTRONOMY & ASTROPHYSICS | 2005年 / 440卷 / 02期

关键词：

stars : chemically peculiar; stars : polarization; stars : magnetic fields; stars : abundances; stars : individual : HD154708;

D O I：

10.1051/0004-6361:200500164

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We have discovered an extraordinarily large mean longitudinal magnetic field of 7.5 kG in the ultra-cool low mass Ap star HD154708 using FORS 1 in spectropolarimetric mode. From UVES spectra, we have measured a mean magnetic field modulus of 24.5 kG. This is the second-largest mean magnetic field modulus ever measured in an Ap star. Furthermore, it is very likely that this star is one of the coolest and least massive among the Ap stars and is located in the H-R diagram in the same region in which rapidly oscillating Ap stars have been detected. We note that all known roAp stars have much smaller magnetic fields, by at least a factor of three.

引用

页码：L37 / L40

页数：4

共 34 条

[21]

KURTZ DW, 1990, ANNU REV ASTRON ASTR, V28, P607

[22]

LUCKE PB, 1990, ASTRON ASTROPHYS, V90, P350

[23] THE CAPE RAPIDLY OSCILLATING AP STAR SURVEY .3. NULL RESULTS OF SEARCHES FOR HIGH-OVERTONE PULSATION [J].