J/A+A/700/A187 Galactic Miras with light-curve asymmetries (Uttenthaler+, 2025)
A population analysis of Galactic Miras with light-curve asymmetries.
Uttenthaler S., Merchan-Benitez P.
<Astron. Astrophys. 700, A187 (2025)>
=2025A&A...700A.187U 2025A&A...700A.187U (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Spectral types ; Infrared
Keywords: stars: AGB and post-AGB - stars: evolution - stars: mass-loss -
stars: oscillations
Abstract:
In a recent publication, we established a close relationship between
light-curve asymmetries in Mira variables and indicators of their dust
mass-loss rate. The light-curve asymmetries appear to be related to
the stars' third dredge-up (3DUP) activity.
We aim to reveal the evolutionary status of M-type Miras with
light-curve asymmetries ("bumps") within the spectral sequence
M-S-C, determine their mass-loss properties, and check possible
evolutionary scenarios.
We analysed a sample of 3100 Miras collected from the ASAS database,
distinguishing between symmetric and asymmetric light curves. We
determined their periods, luminosity functions, and period-luminosity
relations, their locations relative to the Galactic midplane, as well
as mass-loss rate indicators through the 2MASS-WISE colours and the
Gaia-2MASS diagram.
The M-type Miras with symmetric light curves are generally found to
have shorter periods, lower luminosities, a larger average distance to
the Galactic midplane, and lower initial mass than the M-type Miras
with asymmetries. In addition, 25 Miras are proposed as candidates for
new carbon stars.
We propose that the M-type Miras have two distinct populations: M-type
Miras with symmetric light curves, which have lower initial mass
progenitors than M-type Miras with asymmetries, which show signs of
3DUP activity and are the link to the S-type Miras.
Description:
We present the data of the light-curve analysis of 3100 Galactic
Miras. The sample stars were collected from the ASAS catalogue and
Merchan-Benitez et al. (2023A&A...672A.165M 2023A&A...672A.165M, Cat. J/A+A/672/A165); see
Sect. 2 of the present paper. The table contains improved Pulsation
periods, spectral types (see Sect. 6 for new carbon star candidates),
and a classification with respect to the presence of light-curve
asymmetries ("bumps"). Finally, the table lists the newly established
DBSL parameter in the K-[22] versus pulsation period diagram; see
Sect. 5.2 in the paper.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table.dat 44 3100 Results of the new analysis of Mira light curves
in this paper
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See also:
J/A+A/672/A165 : Meandering-period Miras (Merchan-Benitez+, 2023)
Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- Name Object name in Simbad
21- 26 F6.1 d Per Pulsation period
27- 28 A2 --- SpType Spectral type
29- 36 A8 --- SRV? Classification of SRVs or IR according to GCVS
37 I1 --- Bumps [0/1] Presence of light-curve bumps
(0=no, 1=yes)
38- 44 F7.3 mag DBSL ? DBSL parameter in K-[22] vs. P (Sect. 5.2) (1)
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Note (1): We propose a new parameter that we call the distance to the best
separation line (DBSL), defined as the distance between the observed colour
index of a Mira from the line that best separates the Group A and S Miras in
that colour index versus period P (Eqs. 2 and 3), given by the expressions:
Eq. (4): δK-[22]=(K-[22])-(0.011xP-1.380) [mag]
Eq. (5): δ[3.4]-[22]=([3.4]-[22])-(0.0086xP-1.0093) [mag]
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Acknowledgements:
Stefan Uttenthaler, stefan.uttenthale(at)gmail.com
(End) Stefan Uttenthaler [TU Wien, Austria], Patricia Vannier [CDS] 01-Jul-2025