Large pristine samples of red clump stars are highly sought after given that they are standard candles and give precise distances even at large distances. However, it is difficult to cleanly select red clumps stars because they can have the same T$_{\mathrm{eff}}$ and log $g$ as red giant branch stars. Recently, it was shown that the asteroseismic parameters, $\rmΔ$P and $\rm{Δν}$, which are used to accurately select red clump stars, can be derived from spectra using the change in the surface carbon to nitrogen ratio ([C/N]) caused by mixing during the red giant branch. This change in [C/N] can also impact the spectral energy distribution. In this study, we predict the $\rmΔ$P, $\rm{Δν}$, T$_{\mathrm{eff}}$ and log $g$ using 2MASS, AllWISE, \gaia, and Pan-STARRS data in order to select a clean sample of red clump stars. We achieve a contamination rate of $\sim$20\%, equivalent to what is achieved when selecting from T$_{\mathrm{eff}}$ and log $g$ derived from low resolution spectra. Finally, we present two red clump samples. One sample has a contamination rate of $\sim$ 20\% and $\sim$ 405,000 red clump stars. The other has a contamination of $\sim$ 33\% and $\sim$ 2.6 million red clump stars which includes $\sim$ 75,000 stars at distances $>$ 10 kpc. For |b|>30 degrees we find $\sim$ 15,000 stars with contamination rate of $\sim$ 9\%. The scientific potential of this catalog for studying the structure and formation history of the Galaxy is vast given that it includes millions of precise distances to stars in the inner bulge and distant halo where astrometric distances are imprecise.
ATLASGAL: The HCN-IR Star Formation Relation for the Milky Way
University of Kent（肯特大学）；Max-Planck-Institut für Radioastronomie (MPIfR)（马克斯·普朗克射电天文研究所）；Laboratoire d’astrophysique de Bordeaux, Univ. Bordeaux, CNRS（波尔多天体物理实验室，波尔多大学，法国国家科学研究中心）；Institute of Advanced Studies, Nicolaus Copernicus University in Toruń（尼古拉·哥白尼大学托伦高等研究院）；INAF - Istituto di Radioastronomia（意大利国家天体物理研究所射电天文分部）；Argelander-Institut für Astronomie, University of Bonn（波恩大学阿尔兰德天文学研究所）；Department of Physics, University of Bath（巴斯大学物理系）
Stellar Metallicities from SkyMapper Photometry II: Precise photometric metallicities of $\sim$280,000 giant stars with [Fe/H] $< -0.75$ in the Milky Way
Open star clusters in the Milky Way - Comparison of photometric and trigonometric distance scales based on Gaia TGAS data
银河系星团全球巡天（MWSC）是一个包含3061个天体的综合列表，其中提供了基于等时线拟合的星团距离等参数。Tycho-Gaia天体测量解决方案（TGAS）目录是Gaia数据发布1（Gaia DR 1）的一部分，为200多万颗恒星提供精确的三角视差测量，包括星团中的恒星。我们比较了疏散星团光度距离尺度与TGAS三角测量值之间的一致性。TGAS中可能星团成员的平均视差提供了疏散星团的三角距离标度，而光度标度则由MWSC公布的距离给出。64个集群适合比较，因为它们有超过16个可能的成员与视差测量TGAS。我们计算了可能成员的平均光弛度，并将其与MWSC中得出的光度光弛度进行了比较。我们发现一个很好的协议之间的三角TGAS为基础的和测光MWSC为基础的距离尺度的疏散星团，其中的距离小于2.3千秒差距符合在一个水平上约0.1 mas的距离没有依赖。如果真的存在的话，那么在$30^\circ$和$160^\circ$银经之间沿着银河系赤道有一个轻微的系统偏移。
Milky Way Tomography with the SkyMapper Southern Survey. II. Photometric Re-calibration of SMSS DR2
我们应用基于光谱的恒星颜色回归（SCR）方法对SkyMapper南方巡天（SMSS DR 2）的第二次数据发布进行精确的光度重新校准。通过与20多万颗矮星的样本进行比较，这些矮星的恒星大气参数取自GALAH+ DR 3，而$Gaia$ DR 2的光度测量则精确、均匀，在SMSS DR 2的原始光度星表中发现了零点偏移，特别是对重力和金属敏感的$Gaia$波段。对于$uv$带，零点偏移在非常低的消光下接近于零，然后随着$E (B - V)$稳定增加，在$E (B - V) \sim 0.5$磁级分别达到0.174和0.134磁级。这些偏移主要来自SMSS DR 2用于从ATLAS参考星表构建光度校准器的转换中采用的尘埃项。对于$gr$带，零点偏移表现出可忽略的变化与SFD $E(B - V )$，由于其微小的系数上的灰尘项的转换。我们的研究还揭示了所有$uvgr$波段中零点偏移的小但显著的空间变化。外部检查使用斯特伦格伦测光，WD轨迹和SDSS条纹82标准星表独立确认零点发现我们的修订SCR方法。
Constraints on Clumps in the Representative Wind of the WN8 Wolf-Rayet star HD96548 = WR40 with Simultaneous Broadband Light and Linear-Polarisation Variability
A search for new symbiotic stars in the Milky Way: Using machine learning techniques applied to photometric databases
Universidad de La Serena（拉塞雷纳大学）；Instituto de Astronomía y Ciencias Planetarias, Universidad de Atacama（阿塔卡马大学天文与行星科学研究所）；Millennium Institute of Astrophysics (MAS)（天体物理千年研究所）；Gemini Observatory/NSF’s NOIRLab（吉米尼观测站/美国国家光学红外天文实验室）；Universidad Nacional de Hurlingham (UNAHUR)（乌尔里汉国立大学）；Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)（国家科学研究委员会）
