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New photometric data of old open clusters in the anti-galactic center region
Hasegawa T.a, Malasan H.L.a,e, Kawakita H.a, Obayashi H.a, Kurabayashi T.a, Nakai T.b, Hyakkai M.c, Arimoto N.d
a Gunma Astronomical Observatory, Japan
b Sanken Electric Co., Ltd., Japan
c Gunma University, Japan
d National Astronomical Observatory, Japan
e Department of Astronomy, Institut Teknologi Bandung, Indonesia
[vc_row][vc_column][vc_row_inner][vc_column_inner][vc_separator css=”.vc_custom_1624529070653{padding-top: 30px !important;padding-bottom: 30px !important;}”][/vc_column_inner][/vc_row_inner][vc_row_inner layout=”boxed”][vc_column_inner width=”3/4″ css=”.vc_custom_1624695412187{border-right-width: 1px !important;border-right-color: #dddddd !important;border-right-style: solid !important;border-radius: 1px !important;}”][vc_empty_space][megatron_heading title=”Abstract” size=”size-sm” text_align=”text-left”][vc_column_text]We present new photometric data for 14 galactic open clusters taken by the 65cm telescope at Gunma Astronomical Observatory. They were in the anti-galactic center region selected from the Catalog of Open Cluster Data (Lyngå 1987). We estimated the parameters of the clusters, i.e., age, metallicity, distance, and reddening, by fitting Padova isochrones to the color-magnitude diagram. While no clusters were dated to be as old as young globular clusters, 13 clusters out of 14 are older than 1 Gyr, ranging up to ∼ 3.6 Gyr. Bearing in mind that out of approximately 500 clusters dated so far, only 40 clusters are older than 1 Gyr, our sample is exclusively dominated by old clusters. Four clusters were found away from the metallicity gradient curve and age-metallicity relation so far delineated. Especially, 3 metal-rich clusters in the outer disk (Berkeley 36, Biurakan 11, and Biurakan 13) provide evidence against the picture advocated by Twarog et al. (1997, AJ, 114, 2556) that there is a break in the metallicity distribution at rGC = 10kpc and that the outer disk is chemically less evolved than in the inner disk.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Author keywords” size=”size-sm” text_align=”text-left”][vc_column_text][/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Indexed keywords” size=”size-sm” text_align=”text-left”][vc_column_text]Galaxy: evolution,Galaxy: open clusters and associations: general,Galaxy: structure,ISM: extinction[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Funding details” size=”size-sm” text_align=”text-left”][vc_column_text][/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”DOI” size=”size-sm” text_align=”text-left”][vc_column_text]https://doi.org/10.1093/pasj/56.2.295[/vc_column_text][/vc_column_inner][vc_column_inner width=”1/4″][vc_column_text]Widget Plumx[/vc_column_text][/vc_column_inner][/vc_row_inner][/vc_column][/vc_row][vc_row][vc_column][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][/vc_column][/vc_row]