1997A&A...322..280H


Query : 1997A&A...322..280H

1997A&A...322..280H - Astronomy and Astrophysics, volume 322, 280-290 (1997/6-1)

Semiregular variables of types SRa and SRb. Silicate dust emission features.

HRON J., ARINGER B. and KERSCHBAUM F.

Abstract (from CDS):

We have analysed the IRAS-LRS spectra of representative samples of O-rich Semiregular (SR) variables of types SRa and SRb and of Mira variables. The silicate features were extracted by fitting the energy distribution with two blackbodies, approximating the continuous emission from the photosphere and the circumstellar dust. The shape and strength of the silicate features in the LRS range were then studied by computing the residual fluxes in 5 selected wavelength regions covering the whole 10µm and 18µm features and parts of the 10µm feature assigned to emission from olivine and possibly corundum. We compare our approach with previous investigations and argue that a quantitative study of details in the feature shape requires subtraction of the stellar and the dust continuum and the use of flux ratios rather than a discrete classification system. The Miras form an extension of the SRb's towards lower stellar temperatures and higher dust shell opacities and they have slightly higher average dust temperatures. The SRa's seem to be more similar to the Miras in their dust shell properties. The average 10µm feature shapes of the three groups of variables agree, but taking into account the photospheric and dust shell parameters, systematic differences show up. For stars hotter than about 2900K, the 10µm feature width shows a wide range of values but no clear trend with the stellar temperature or the optical depth of the dust shell. These stars are generally SRb variables and have the thinnest dust envelopes. At cooler stellar temperatures, where mostly Miras are found, the optical depth of the dust shell determines the feature width in the sense that thicker shells have narrower features. It appears that the 13µm feature is obvious only in a narrow range of effective temperature and optical depth of the dust shell. We discuss our results in terms of radiative transfer effects, differences in the average grain size, annealing and hydration of amorphous silicates and contributions from other dust components. Of these possibilities the last one seems to be most plausible with regard to the behavior of the 10µm feature width. The observations can be interpreted in terms of changing contributions from olivine and corundum possibly caused by an increasing amount of dust processing (Miras) and the influence of the atmospheric structure on the formation of these dust components (SRb's).

Abstract Copyright:

Journal keyword(s): stars: AGB and post-AGB - stars: circumstellar matter - stars: mass-loss - infrared: stars

Simbad objects: 82

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Number of rows : 82
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
#notes
1 V* VX And C* 00 19 54.0161311920 +44 42 33.895984824   12.23 7.80     C-J4.5 155 0
2 V* ST Psc LP* 01 27 49.6277966280 +16 42 08.954189928   10.96 9.69     M5 26 0
3 V* SV Psc LP* 01 46 35.3435781336 +19 05 04.537113684   10.02 8.773 8.41   M5 41 0
4 V* R Cet Mi* 02 26 02.3168041392 -00 10 41.813680476   10.5 7.20     M4-5e 135 0
5 V* W Hor LP* 02 44 14.7619581984 -54 18 04.117568436   10.04 8.84     M5/7 35 0
6 V* RR Eri LP* 02 52 14.1850966152 -08 16 01.430627268   8.59 7.16     M5III 52 0
7 V* R Hor Mi* 02 53 52.7701013592 -49 53 22.730520228     3.92 4.99 1.51 M5-7e 177 0
8 V* U Ari Mi* 03 11 03.0366056664 +14 48 00.300444804   9.82 7.20     M4.5-7.5e 111 0
9 V* SU Eri LP* 03 51 27.0237925776 -01 22 16.336692408   9.71 8.545 8.27   M6III 27 0
10 V* U Men OH* 04 09 35.5833357218 -81 51 17.682061033           M3 58 0
11 V* W Eri Mi* 04 11 31.0247657856 -25 08 02.308262100   10.62 7.50   8.20 M7e 113 1
12 V* R Tau Mi* 04 28 18.0026579160 +10 09 44.795528028   11.64 7.60     M6.5-9e 133 0
13 V* RV Cam LP* 04 30 41.6803544040 +57 24 42.284271780   9.65 8.20     M4II-III 59 0
14 V* R Cae Mi* 04 40 30.0847911768 -38 14 06.929226636   11.1 6.70     M6e 89 0
15 V* U Dor OH* 05 10 08.8413498888 -64 19 04.255801500   11.86 8.10     M8IIIe 58 0
16 V* S Pic Mi* 05 10 57.2451886368 -48 30 25.453894284   10.46 6.50 9.45   M7e 86 0
17 V* RX Lep AB* 05 11 22.8715425 -11 50 56.722211 8.37 7.14 5.68     M6III 98 0
18 V* FX Ori LP* 05 41 55.0845180480 +14 50 01.987012068   10.68 9.17     M5: 18 0
19 V* S Lep LP* 06 05 45.5496784008 -24 11 44.015025408 9.72 8.42 6.82 4.12 1.75 M6+IIIa 101 0
20 V* X CMa LP* 06 56 45.9301741704 -23 57 55.443683628   10.16 8.99     M5/6III 15 0
21 V* HU Pup Mi* 07 55 40.1845649808 -28 38 54.673845576   10.81 8.79     M3 41 0
22 V* U Pup Mi* 08 00 50.4904071144 -12 50 29.130830520   12.07 10.90     M8e 64 0
23 V* Y Pup LP* 08 12 37.4072070264 -35 08 47.448138120   10.65 9.06     M7 18 0
24 V* Z Cnc LP* 08 22 25.2910564920 +14 59 31.899972372   9.83 8.55     M6III 62 0
25 V* AK Hya LP* 08 39 53.5421610192 -17 18 10.730602800   8.00 6.67     M6III 73 0
26 V* EP Vel Mi* 08 41 41.2694710368 -48 06 45.283046148   11.02 9.62 7.72   M6 22 0
27 V* T Cnc C* 08 56 40.1375904072 +19 50 56.919947352   12.07 7.60     C-N5 130 1
28 V* SY Vel LP* 09 12 25.7260697400 -43 46 38.706262860   9.40 8.12     M5/6III 20 0
29 V* GM Vel LP* 09 47 40.8962951280 -46 38 25.412036964   10.35 8.94     M7III 17 0
30 V* SZ Vel LP* 09 50 07.4027816496 -44 39 07.566619032   10.68 9.36     M5 12 0
31 V* SU Car Mi* 10 13 30.4202025120 -60 53 09.497886720     11.28     M9 20 0
32 V* VZ Vel OH* 10 28 11.0083798248 -51 11 07.684927008   11.96 10.87     M7 22 0
33 V* HH Vel LP* 10 42 09.1970826720 -53 43 13.434524292   10.31 8.70     M5/6III 14 0
34 V* R Crt AB* 11 00 33.8525664720 -18 19 29.582708520   10.33 9.80     M7/8III 205 0
35 V* X Cen Mi* 11 49 11.7844994832 -41 45 27.280751328   10.843 9.602 8.236   M6.5e 70 0
36 V* ST Cru Mi* 12 25 45.7466648616 -60 00 00.104376744   12.54 11.51     M10 19 0
37 V* U Cru Mi* 12 32 23.7389107728 -57 34 58.864094148   12.60 12.07     M8: 20 0
38 V* RT Vir AB* 13 02 37.9814644272 +05 11 08.362884984 10.07 9.07 7.41     M8III 310 0
39 V* V CVn Mi* 13 19 27.7658321448 +45 31 37.656251760 9.55 8.39 6.74 6.13   M4-M6e 162 0
40 V* V744 Cen LP* 13 39 59.8066660 -49 56 59.839473 8.65 7.50 6.00     M6III 74 0
41 * tet Aps LP* 14 05 19.8778357 -76 47 48.320384 8.10 7.05 5.50     M6.5III: 119 0
42 V* RU Hya Mi* 14 11 34.3968070483 -28 53 07.438986282   11.38 7.20 7.54   M6.5e 124 0
43 V* RS Vir Mi* 14 27 16.3912599864 +04 40 41.126332044   10.27 7.00     M8 203 0
44 V* RV Boo AB* 14 39 15.8615969712 +32 32 22.250745204   9.50 7.90     M5-6IIIe 91 0
45 V* RW Boo LP* 14 41 13.3762067784 +31 34 19.711947072 10.23 9.34 8.00     M5III: 56 0
46 V* FY Lib LP* 14 57 46.5477035016 -12 26 15.326281032   8.63 7.23     M5III 55 0
47 V* Y Lup Mi* 14 59 36.8233128072 -54 57 56.206326960     10.64     M7e 40 0
48 V* Y Ser Mi* 15 14 01.4484652440 -01 53 11.041042344   11.1 9.46     M4III 32 0
49 V* RU CrB Mi* 15 35 36.5760011568 +25 45 10.100362104   10.64 9.27 8.24   M8 30 0
50 V* R Nor Mi* 15 35 57.3532146231 -49 30 28.650984474   10.27 8.806 10.86   M3-7 74 0
51 V* BG Ser Mi* 15 43 36.7736621640 -01 42 37.672468020   11.62 10.40     M7 55 0
52 V* RS CrB Mi* 15 58 30.7643738880 +36 01 19.724981484   8.88 7.44     M7 47 0
53 V* X Her AB* 16 02 39.1730141112 +47 14 25.265335956   7.64 6.58     M6III 232 0
54 V* RT Sco S* 17 03 32.5593710616 -36 55 13.694502792     7.00     S7,2 71 0
55 V* RT Oph Mi* 17 56 32.0349186096 +11 10 09.696002556     8.60 10.69   M8e 80 0
56 V* V988 Oph LP* 18 26 52.8363330600 +03 54 49.217099256   9.45 7.93     M5/6III 25 0
57 V* RT Pav LP* 18 36 30.5362753944 -69 53 06.093808260   9.56 8.20     M4/5III 18 0
58 V* SY Lyr LP* 18 41 27.5191158576 +28 48 51.929737236   11.64 10.42     ~ 20 0
59 V* MZ Her LP* 18 48 16.8160272384 +19 06 49.529070612   11.28 9.850     M6 15 0
60 V* UX Sgr LP* 18 54 54.4757206800 -16 31 31.435169988   9.19 7.66     M5/6III 26 0
61 V* UV Aql C* 18 58 32.4279985824 +14 21 49.597230024   14.65 11.10 9.30 7.83 C5,3 72 0
62 V* RW Sgr Mi* 19 13 54.5952059112 -18 51 42.051932316   10.64 9.00     M3(III)e 32 0
63 V* V366 Aql Mi* 19 26 24.4283572992 +02 17 08.800619748           M7 11 0
64 V* RR Sgr Mi* 19 55 56.4336636984 -29 11 24.128616804 8.55 7.66 6.15     M6-7e 112 0
65 V* RR Aql Mi* 19 57 36.0616870728 -01 53 11.339520360     7.80 7.45   M7.5e 289 2
66 V* V718 Cyg LP* 20 03 05.1189706992 +30 20 12.832840104     12.26 9.98   M3 28 0
67 V* X Pav AB* 20 11 45.8638935384 -59 56 12.809676840   9.69 9.20     M8III 65 1
68 V* AI Cyg LP* 20 31 45.2320324152 +32 31 21.219008196   10.18 8.75     M6III: 28 0
69 V* RU Cap OH* 20 32 34.0930684272 -21 41 25.584207648     12     M9 47 0
70 V* W Aqr Mi* 20 46 25.0735070472 -04 05 00.416952528     11     M6 58 0
71 V* RZ Cyg Mi* 20 51 53.1763632600 +47 21 20.369735640   11.40 11.25 7.91   M7 44 0
72 V* S Ind Mi* 20 56 23.2660811616 -54 19 26.858069976   10.31 7.90     M6e 55 0
73 V* RS Cap AB* 21 07 15.4311630672 -16 25 21.462156804   9.56 8.36     M6/7III 67 0
74 V* Y Pav C* 21 24 16.7499375384 -69 44 01.960245204 12.63 9.23 6.41     C7,3 82 0
75 V* EP Aqr AB* 21 46 31.8494911920 -02 12 45.928582560   7.93 6.78     M7-III: 233 0
76 V* S Gru Mi* 22 26 05.4746030880 -48 26 18.747922776 7.72 7.35 6.00 8.89   M8(III)e 80 1
77 IRC +60359 LP* 22 32 36.6955515432 +55 26 04.895425140   12.66 11.16     M6 16 0
78 V* BD Peg LP* 22 42 58.9638559056 +28 09 25.624404828   10.04 8.84     M8 27 0
79 V* V PsA AB* 22 55 19.6832667720 -29 36 44.521985340   10.18 9.30     M7/8III 49 0
80 V* BI Peg Mi* 22 57 51.7675038600 +18 01 00.790847760   12.47 10.80     M9 32 0
81 V* AK Peg Mi* 23 03 11.0612512680 +11 21 32.901948648   10.94 8.60     M5 17 0
82 V* R Peg Mi* 23 06 39.1661885712 +10 32 36.080828808 9.43 9.07 7.79 4.87 2.35 M6-8.5e 219 0

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2023.02.08-04:00:57

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