2012A&A...544A..13K


Query : 2012A&A...544A..13K

2012A&A...544A..13K - Astronomy and Astrophysics, volume 544A, 13-13 (2012/8-1)

Models of AM Canum Venaticorum star outbursts.

KOTKO I., LASOTA J.-P., DUBUS G. and HAMEURY J.-M.

Abstract (from CDS):

Outbursting AM CVn stars exhibit outbursts similar to those observed in different types of dwarf novae. Their light-curves combine the characteristic features of SU UMa, ER UMa, Z Cam, and WZ Sge-type systems but also show a variety of properties never observed in dwarf novae. The compactness of AM CVn orbits and their unusual chemical composition make these systems valuable testbeds for outburst models. We aim for a better understanding of the role of helium in the accretion disc instability mechanism, testing the model for dwarf novae outbursts in the case of AM CVn stars, and aim to explain the outburst light-curves of these ultra-compact binaries. We calculated the properties of the hydrogen-free AM CVn stars using our previously developed numerical code adapted to the different chemical composition of these systems and supplemented with formulae accounting for mass transfer rate variations, additional sources of the disc heating, and the primary's magnetic field. We discovered how helium-dominated discs react to the thermal-viscous instability and were able to reproduce various features of the outburst cycles in the light-curves of AM CVn stars. The AM CVn outbursts can be explained by the suitably adapted dwarf-nova disc instability model but, as in the case of its application to hydrogen-dominated cataclysmic variables, one has to resort to additional mechanisms to account for the observed superoutbursts, dips, cycling states, and standstills. We show that the enhanced mass-transfer rate, due presumably to variable irradiation of the secondary, must not only be taken into account but is a determining factor that shapes AM CVn star outbursts. The cause of the variable secondary's irradiation has yet to be understood; the best candidate is the precession of a tilted/warped disc.

Abstract Copyright:

Journal keyword(s): accretion, accretion disks - instabilities - binaries: close - stars: dwarf novae

CDS comments: Paragraph 4.1 SDSS J0902 not fientified (incomplete format). Table B.1. AT Ara not identified.

Simbad objects: 39

goto Full paper

goto View the references in ADS

Number of rows : 39
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024
#notes
1 PMMR 17 V* 00 48 16.5849352104 -74 35 51.490968828   13.99 12.46     M4+ 13 2
2 V* AR And CV* 01 45 03.2715491016 +37 56 33.237881916           ~ 83 0
3 V* ES Cet CV* 02 00 52.2358544184 -09 24 31.643735904   16.3   16.7 16.97 ~ 81 0
4 V* AF Cam CV* 03 32 15.4983960264 +58 47 22.148326104     13.40     ~ 49 0
5 V* BF Eri CV* 04 39 29.9447621952 -04 35 58.869385008   15.07 14.58 14.71   D+K3 44 0
6 V* SS Aur CV* 06 13 22.4340408984 +47 44 25.345431780   16.06 15.81     sdBe 260 0
7 V* CZ Ori CV* 06 16 43.2247568736 +15 24 11.297210616   12.81 12.81 16.17   OB- 96 0
8 V* CW Mon CV* 06 36 54.5810314968 +00 02 17.285344080     11.90     ~ 69 0
9 PTF1 J071912.13+485834.0 CV* 07 19 12.1179047304 +48 58 34.704243516           ~ 21 0
10 V* BV Pup CV* 07 49 05.2533624216 -23 34 00.396724440           ~ 63 0
11 V* U Gem CV* 07 55 05.2323858391 +22 00 05.045435077   15.3 14.54     DA 1097 0
12 SDSS J080449.49+161624.8 CV* 08 04 49.4916114456 +16 16 24.871098576           ~ 24 0
13 RX J0806.3+1527 XB* 08 06 22.9520149296 +15 27 31.002199488   20.7 20   21.2 ~ 141 0
14 V* YZ LMi CV* 09 26 38.7250463760 +36 24 02.456809632           DB 63 0
15 V* CH UMa CV* 10 07 00.7217843640 +67 32 47.506618176   15.97       ~ 110 0
16 V* V442 Cen CV* 11 24 51.9051069168 -35 54 36.729015624           ~ 53 0
17 V* TW Vir CV* 11 45 21.1711886016 -04 26 05.777690964   17.38   15.03   M2 143 0
18 V* MU Cen CV* 12 12 53.8782227400 -44 28 16.025209824   14.534 14.059 14.752   ~ 43 0
19 V* AM CVn CV* 12 34 54.6231062664 +37 37 44.120620056   14.02 14.13 14.47   DBnnp 404 0
20 2QZ J124058.0-015920 CV* 12 40 58.0278645048 -01 59 19.190494500   19.2   19.6   DBe 55 0
21 G 61-29 CV* 13 05 42.4009686696 +18 01 03.763561619   16.059 16.101 15.825   DBe 265 0
22 V* V396 Hya CV* 13 12 46.4399548464 -23 21 32.595789924   18.9   17.5   DD 101 0
23 V* V803 Cen CV* 13 23 44.5389056832 -41 44 29.446810404   16.8 14.42     ~ 147 0
24 V* BV Cen CV* 13 31 19.5105743208 -54 58 33.657394152     13.151 12.746 12.226 G5-8IV/V 188 0
25 V* CR Boo CV* 13 48 55.2218717736 +07 57 35.724118680     15.00     ~ 175 0
26 V* HP Lib CV* 15 35 53.0715009672 -14 13 12.215196048   13.55       Bpec 102 0
27 PG 1550+191 CV* 15 52 47.1968971224 +18 56 28.844471472   16.4 15.46 17.0   M6.5Ve 189 0
28 V* EX Dra CV* 18 04 14.2486747659 +67 54 12.271788519   14.5 14.7     ~ 125 0
29 V* AM Her CV* 18 16 13.2546541781 +49 52 04.759861155   15.124 14.808 13.525   M4.5-5Ve 960 0
30 UCAC3 260-149285 CV* 19 08 17.0797893576 +39 40 36.448547088   15.18 15.43 17.11 15.24 ~ 36 0
31 RX J1914.4+2456 XB* 19 14 26.0922577338 +24 56 43.322660677           ~ 136 0
32 V* KL Dra CV* 19 24 38.2451853000 +59 41 46.722283224   16.8       DB+ 60 1
33 V* EY Cyg CV* 19 54 36.7420149648 +32 21 55.087471404           sdBe+K0V 122 0
34 V* UU Aql CV* 19 57 18.7656631920 -09 19 21.064632708           K7-M0V 93 0
35 V* WZ Sge CV* 20 07 36.5037622512 +17 42 14.733254952   15.30 15.20     DAepv 943 0
36 V* SS Cyg CV* 21 42 42.8034497592 +43 35 09.867842484 11.07 12.651 12.032 9.326   K5V 1287 1
37 V* RU Peg CV* 22 14 02.5505986656 +12 42 11.278107972     12     sdBe+G8IV:n 305 0
38 V* IP Peg CV* 23 23 08.5362249504 +18 24 59.206884012           M2 380 0
39 V* DX And CV* 23 29 46.6838648136 +43 45 04.034136924           ~ 99 0

To bookmark this query, right click on this link: simbad:objects in 2012A&A...544A..13K and select 'bookmark this link' or equivalent in the popup menu