Archival Vilnius CCD photometric observations are presented for the heavily reddened star cluster Melotte 105, resulting in colour-magnitude diagrams and spectral class estimates. There is considerable lack of agreement between studies for reddening, age and distance for this cluster explaining why the archival data are being made available by this paper. The derived reddening $$E(B-V)=0.34\pm 0.04$$ E ( B - V ) = 0.34 ± 0.04 mag and the distance $$V-M_{V}=12.9\pm 0.3$$ V - M V = 12.9 ± 0.3 mag are directly from the Vilnius photometry. The Gaia Data Release 2 (DR2) and Vilnius photometric data of the cluster were used to estimate the structural parameters of the cluster, probability of stellar membership in the cluster, the distance modulus and the cluster age. Lack of Y band observations prevented determination of metal abundance. The values of the colour excess and distance module are determined by two different methods (i.e., Q and Zero Age Main Sequence or ZAMS methods). A distance modulus of $$12.85\pm 0.07$$ 12.85 ± 0.07 mag was derived by ZAMS fitting, in good agreement with the above estimate. ZAMS fitting indicates a reddening of $$0.403 \pm 0.02$$ 0.403 ± 0.02 mag, within two sigma of the estimate above. The cluster’s metallicity and age are estimated to be 0.24 dex and $$240\pm 25$$ 240 ± 25 Myr, respectively. The derived mass function is in good agreement with the Salpeter slope. The cluster space velocity components ( U , V , W ) were determined as ( $$-3.90\pm 3.34$$ - 3.90 ± 3.34 , $$-13.76\pm 5.69$$ - 13.76 ± 5.69 , $$+3.45\pm 0.41$$ + 3.45 ± 0.41 ) km/s. Perigalactic and apogalactic distances were obtained as $$R_{p}=6.85$$ R p = 6.85 and $$R_{a}=7.44$$ R a = 7.44 kpc respectively. The maximum vertical distance from the Galactic plane was calculated as $$Z_{\mathrm{max}}=84$$ Z max = 84 pc and the eccentricity of the orbit was determined as $$e=0.042$$ e = 0.042 .

中文翻译：

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Melotte 105 的维尔纽斯光度测量和盖亚天体测量

存档的维尔纽斯 CCD 光度观测被呈现为严重变红的星团 Melotte 105，从而产生颜色-星等图和光谱类别估计。对这个集群的变红、年龄和距离的研究之间相当缺乏一致，这解释了为什么本文提供了档案数据。推导出的红化 $$E(BV)=0.34\pm 0.04$$ E ( B - V ) = 0.34 ± 0.04 mag 和距离 $$V-M_{V}=12.9\pm 0.3$$ V - MV = 12.9 ± 0.3 mag 直接来自维尔纽斯测光。Gaia Data Release 2 (DR2) 和星团的维尔纽斯光度数据被用来估计星团的结构参数、星团中恒星成员的概率、距离模数和星团年龄。缺乏 Y 波段观测阻止了金属丰度的确定。颜色过量和距离模块的值由两种不同的方法（即 Q 和零年龄主序或 ZAMS 方法）确定。通过 ZAMS 拟合推导出 $$12.85\pm 0.07$$12.85 ± 0.07 mag 的距离模量，与上述估计非常吻合。ZAMS 拟合表明红化为 $0.403 \pm 0.02$$ 0.403 ± 0.02 mag，在上述估计值的 2 西格玛以内。该星团的金属丰度和年龄估计分别为 0.24 dex 和 $$240\pm 25$$ 240 ± 25 Myr。导出的质量函数与 Salpeter 斜率非常吻合。星团空间速度分量 ( U , V , W ) 被确定为 ( $$-3.90\pm 3.34$$ - 3.90 ± 3.34 , $$-13.76\pm 5.69$$ - 13.76 ± 5.69 , $$+3.45\pm 0.41$$ + 3.45 ± 0.41 ) 公里/秒。近银河和远银河距离为 $$R_{p}=6.85$$R p = 6.85 和 $$R_{a}=7。44$$ R a = 7.44 kpc 分别。与银河平面的最大垂直距离计算为 $$Z_{\mathrm{max}}=84$$ Z max = 84 pc 并且轨道的偏心率确定为 $$e=0.042$$ e = 0.042 。