2017A&A...608A..99K


C.D.S. - SIMBAD4 rel 1.7 - 2019.12.14CET03:11:57

2017A&A...608A..99K - Astronomy and Astrophysics, volume 608A, 99-99 (2017/12-1)

Amplitude variations of modulated RV Tauri stars support the dust obscuration model of the RVb phenomenon.

KISS L.L. and BODI A.

Abstract (from CDS):

Context. RV Tauri-type variables are pulsating post-asymptotic giant branch (AGB) stars that evolve rapidly through the instability strip after leaving the AGB. Their light variability is dominated by radial pulsations. Members of the RVb subclass show an additional variability in the form of a long-term modulation of the mean brightness, for which the most popular theories all assume binarity and some kind of circumstellar dust. Here we assess whether or not the amplitude modulations are consistent with the dust obscuration model.
Aims. We measure and interpret the overall changes of the mean amplitude of the pulsations along the RVb variability.
Methods. We compiled long-term photometric data for RVb-type stars, including visual observations of the American Association of Variable Star Observers, ground-based CCD photometry from the OGLE and ASAS projects, and ultra-precise space photometry of one star, DF Cygni, from theKepler space telescope. After converting all the observations to flux units, we measure the cycle-to-cycle variations of the pulsation amplitude and correlate them to the actual mean fluxes.
Results. We find a surprisingly uniform correlation between the pulsation amplitude and the mean flux; they scale linearly with each other for a wide range of fluxes and amplitudes. This means that the pulsation amplitude actually remains constant when measured relative to the system flux level. The apparent amplitude decrease in the faint states has long been noted in the literature but it was always claimed to be difficult to explain with the actual models of the RVb phenomenon. Here we show that when fluxes are used instead of magnitudes, the amplitude attenuation is naturally explained by periodic obscuration from a large opaque screen, one most likely corresponding to a circumbinary dusty disk that surrounds the whole system.

Abstract Copyright: © ESO, 2017

Journal keyword(s): stars: AGB and post-AGB - stars: oscillations - stars: variables: general - binaries: general - binaries: general

Simbad objects: 21

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Number of rows : 21

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 NAME SMC G 00 52 38.0 -72 48 01   2.79 2.2     ~ 9141 1
2 NAME Magellanic Clouds GrG 03 00 -71.0           ~ 5410 1
3 V* RV Tau Mi* 04 47 06.7238218181 +26 10 45.530144720   11.00 9.80     K0 262 0
4 OGLE LMC-T2CEP-200 RV* 05 13 56.4547228642 -69 31 58.406895002 19.350 16.029 16.124 15.660 15.092 ~ 12 0
5 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 14392 1
6 V* SU Gem Mi* 06 14 00.0255668685 +27 42 12.183565975   11.70 10.19     F8/G0Ib 46 0
7 V* U Mon RV* 07 30 47.4734611972 -09 46 36.788534824 8.22 7.00 5.82     G8/K0Ib/II 191 0
8 V* AR Pup RV* 08 03 01.6539854234 -36 35 47.938553885   10.25 9.55     Rpec 78 0
9 V* IW Car RV* 09 26 53.3043066360 -63 37 48.939300156   9.07 7.90     F7/8 83 0
10 V* SX Cen RV* 12 21 12.5740806517 -49 12 41.059392756   10.11 9.60     B5III 64 0
11 OGLE BLG195.3 125143 WV* 17 54 42.2390491027 -29 11 43.311294451     18.407   15.034 ~ 6 0
12 OGLE BLG164.7 91690 WV* 17 54 58.8036426519 -31 54 45.016799434     15.483   13.058 ~ 5 0
13 V* AI Sco RV* 17 56 18.5761406960 -33 48 43.261703840   10.99 9.98     G5 42 0
14 OGLE BLG-T2CEP-215 WV* 17 57 52.3033641067 -30 06 43.323524646     17.348   14.084 ~ 4 0
15 OGLE BLG215.6 178419 WV* 18 00 02.0367138663 -28 11 17.902814346     16.312   14.158 ~ 5 0
16 OGLE BLG-LPV-203342 WV* 18 05 06.3049598487 -28 05 54.546304331     13.963   12.191 ~ 6 0
17 OGLE BLG236.5 174020 WV* 18 09 34.1104370572 -26 49 10.366532555     16.147   13.200 ~ 5 0
18 V* AC Her pA* 18 30 16.2374666779 +21 52 00.618442618 8.00 7.79 7.01     F4Ibp 314 0
19 V* R Sct RV* 18 47 28.9509385830 -05 42 18.537825839 8.30 6.67 5.20 4.14 3.37 K4/5pec 294 0
20 V* DF Cyg RV* 19 48 53.9459890026 +43 02 14.543926251   12.19 10.80   10.484 G6/7Ib/IIa 40 0
21 NAME Galactic Bulge reg ~ ~           ~ 3264 0

    Equat.    Gal    SGal    Ecl

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2019.12.14-03:11:57

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