Interstellar polarization and extinction towards the young open
cluster NGC 1502

J 2018

Interstellar polarization and extinction towards the young open cluster NGC 1502

TOPASNA, Gregg; Nadia KALTCHEVA a Ernst PAUNZEN

Základní údaje

Originální název

Interstellar polarization and extinction towards the young open cluster NGC 1502

Autoři

TOPASNA, Gregg (840 Spojené státy); Nadia KALTCHEVA (840 Spojené státy) a Ernst PAUNZEN (40 Rakousko, garant, domácí)

Vydání

ASTRONOMY & ASTROPHYSICS, LES ULIS CEDEX A, EDP SCIENCES S A, 2018, 1432-0746

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10308 Astronomy

Stát vydavatele

Francie

Utajení

není předmětem státního či obchodního tajemství

Kód RIV

RIV/00216224:14310/18:00103432

Organizační jednotka

Přírodovědecká fakulta

DOI

http://dx.doi.org/10.1051/0004-6361/201731903

UT WoS

000440874200002

EID Scopus

2-s2.0-85064403508

Klíčová slova anglicky

stars: early type; open clusters and associations: individual: NGC 1502

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 13. 11. 2018 11:13, doc. Ernst Paunzen, Dr.rer.nat

Anotace

V originále

Aims. NGC 1502 is located at the periphery of the Cam OB1 association and probably within the Orion Spur, with published distance estimates varying between 0.7 and 1.5 kpc. We combine new polarimetric observations and existing uvby beta and UBV photometries to provide new estimates of the cluster's parameters. Methods. We present new multi-wavelength polarization observations of 22 stars in the direction of the cluster and, using the wavelength of maximum polarization, calculate the total-to-selective extinction ratio for each of these stars. These are combined with homogenized uvby beta and UBV photometries to obtain the individual stellar distances and study the structure of the field. Results. We found no evidence of significant extinction variation across the cluster and obtained an average color excess E(b - y) = 0.56 +/- 0.02 mag, corresponding to E(B V) = 0.76 mag. Given the uniformity of both p(max) and lambda(max) toward the cluster and the distribution of the color excess with distance, it seems likely that the polarization in this region arises from aligned dust grains in the foreground of the cluster, not farther than 500-600 pc. Based on 20 stars located beyond 500 pc within the studied field of view, we obtained an average polarization-based total-to-selective extinction ratio R = 2.83 +/- 0.14 yielding visual absorption A(V) = 2.14 +/- 0.16 mag. Using 11 stars with uvby beta data that represent the main sequence of the cluster, we calculated a photometric distance of 1117(-89)(+96) pc. This estimate is fully supported by the UBV-based analysis and the new individual membership probabilities that we derive. Assuming a solar metallicity yields an age of 5 Myr. Our analysis yields controversial results regarding the membership of the stars associated with the SZ Cam system (HD 25638 and HD 25639) to the cluster.

Návaznosti

7AMB17AT030, projekt VaV

Název: Analýza hvězd se skvrnami pomocí kvalitních pozorovacích dat

Investor: Ministerstvo školství, mládeže a tělovýchovy ČR, Analýza hvězd se skvrnami pomocí kvalitních pozorovacích dat

Citovat

TOPASNA, Gregg; Nadia KALTCHEVA a Ernst PAUNZEN. Interstellar polarization and extinction towards the young open cluster NGC 1502. ASTRONOMY & ASTROPHYSICS. LES ULIS CEDEX A: EDP SCIENCES S A, 2018, roč. 615, č. 8, s. 166-181. ISSN 1432-0746. Dostupné z: https://dx.doi.org/10.1051/0004-6361/201731903.

@article{1428059,
   author = {Topasna, Gregg and Kaltcheva, Nadia and Paunzen, Ernst},
   article_location = {LES ULIS CEDEX A},
   article_number = {8},
   doi = {http://dx.doi.org/10.1051/0004-6361/201731903},
   keywords = {stars: early type; open clusters and associations: individual: NGC 1502},
   language = {eng},
   issn = {1432-0746},
   journal = {ASTRONOMY & ASTROPHYSICS},
   title = {Interstellar polarization and extinction towards the young open cluster NGC 1502},
   volume = {615},
   year = {2018}
}

TY  - JOUR
ID  - 1428059
AU  - Topasna, Gregg - Kaltcheva, Nadia - Paunzen, Ernst
PY  - 2018
TI  - Interstellar polarization and extinction towards the young open cluster NGC 1502
JF  - ASTRONOMY & ASTROPHYSICS
VL  - 615
IS  - 8
SP  - 166-181
EP  - 166-181
PB  - EDP SCIENCES S A
SN  - 14320746
KW  - stars: early type
KW  - open clusters and associations: individual: NGC 1502
N2  - Aims. NGC 1502 is located at the periphery of the Cam OB1 association and probably within the Orion Spur, with published distance estimates varying between 0.7 and 1.5 kpc. We combine new polarimetric observations and existing uvby beta and UBV photometries to provide new estimates of the cluster's parameters. Methods. We present new multi-wavelength polarization observations of 22 stars in the direction of the cluster and, using the wavelength of maximum polarization, calculate the total-to-selective extinction ratio for each of these stars. These are combined with homogenized uvby beta and UBV photometries to obtain the individual stellar distances and study the structure of the field. Results. We found no evidence of significant extinction variation across the cluster and obtained an average color excess E(b - y) = 0.56 +/- 0.02 mag, corresponding to E(B V) = 0.76 mag. Given the uniformity of both p(max) and lambda(max) toward the cluster and the distribution of the color excess with distance, it seems likely that the polarization in this region arises from aligned dust grains in the foreground of the cluster, not farther than 500-600 pc. Based on 20 stars located beyond 500 pc within the studied field of view, we obtained an average polarization-based total-to-selective extinction ratio R = 2.83 +/- 0.14 yielding visual absorption A(V) = 2.14 +/- 0.16 mag. Using 11 stars with uvby beta data that represent the main sequence of the cluster, we calculated a photometric distance of 1117(-89)(+96) pc. This estimate is fully supported by the UBV-based analysis and the new individual membership probabilities that we derive. Assuming a solar metallicity yields an age of 5 Myr. Our analysis yields controversial results regarding the membership of the stars associated with the SZ Cam system (HD 25638 and HD 25639) to the cluster.
ER  -

TOPASNA, Gregg; Nadia KALTCHEVA a Ernst PAUNZEN. Interstellar polarization and extinction towards the young open cluster NGC 1502. \textit{ASTRONOMY \&{}amp; ASTROPHYSICS}. LES ULIS CEDEX A: EDP SCIENCES S A, 2018, roč.~615, č.~8, s.~166-181. ISSN~1432-0746. Dostupné z: https://dx.doi.org/10.1051/0004-6361/201731903.

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