We present a multi-epoch, accurate UBVRcIc photometric catalog of 83 symbiotic stars and related objects, measured while calibrating the Henden and Munari (2000, 2001, 2006) photometric sequences around them. The vast majority of the observations where collected in the time interval between October 19, 1998 to April 21, 2002 with the 1.0-m Ritchey-Chretien telescope of the U. S. Naval Observatory, Flagstaff Station (Arizona). On average, UBVRcIc data are given on 3.6 epochs for each program star. The overall budget error of the data is usually better than 0.01 mag.
All-Sky spectrally matched UBVRI-ZY and u'g'r'i'z' magnitudes for stars in the Tycho2 catalog
我们提出了拟合UBVRI-ZY和u 'g' r 'i'z'星等，光谱类型和距离的2.4M恒星，来自合成测光库光谱，最好的匹配Tycho 2 BtVt，NOMAD Rn和2 MASS JHK_{2/S}目录的星等。我们提出了类似的合成多滤波器的星等，类型和距离的4.8米的恒星与2 MASS和SDSS测光g<16的斯隆调查区域内，兰道尔特和斯隆的主要标准，以及斯隆北方（PT）和南方的二级标准。BtVt、UBVRI、ZvYv、JHK_{2/S}、JHK_{MKO}、Stromgren uvby、Sloan u 'g' r 'i'z'和ugriz的合成幅度零点在20个calspec分光光度标准上校准。对于覆盖-0.3 < V-I < 4.6的颜色范围的标准品，UBVRI和ugriz零点的分散度为1- 3%;对于其他滤光片，其分散度在2- 5%范围内。对Tycho 2星的光谱匹配拟合，在UBVRI或u 'g' r 'i' z '中，估计每星的1-sigma误差分别为~0.2，0.15，0.12，0.10和0.08 mags;对于至少70%的SDSS调查区域，g<16，在u 'g' r 'i'z'或UBVRI中，估计每星的1-sigma误差约为0.2，0.06，0.04，0.04，0.05。Tycho 2恒星的密度平均为每平方度60颗恒星，提供了足够的恒星，使大多数视场为0.5度或更大的数字图…
Theoretical predictions of the population of Galactic symbiotic stars (SySts) are highly inconsistent with the current known population. Despite intense effort over the past decades, observations are still far below the predictions. The majority of known SySts so far are identified based on selection criteria established in the optical regime. The recent discovery of SU Lyn with very faint optical emission lines uncloaked a subgroup of SySts with accreting-only white dwarfs. In this particular case, the luminous red giant may overshadow the dimmed white dwarf companion. A new approach to searc…
In this second paper in a series of papers based on the most-up-to-date catalogue of symbiotic stars (SySts), we present a new approach for identifying and distinguishing SySts from other Halpha emitters in photometric surveys using machine learning algorithms such as classification tree, linear discriminant analysis, and K-nearest neighbour. The motivation behind of this work is to seek for possible colour indices in the regime of near- and mid-infrared covered by the 2MASS and WISE surveys. A number of diagnostic colour-colour diagrams are generated for all the known Galactic SySts and sever…
Hen 3-160 is reported in Belczynski et al.'s (2000) catalog as a symbiotic binary system with M7 giant donor. Using $V$- and $I$-band photometry collected over 20 years we have found that the giant is a Mira variable pulsating with 242.5-day period. The period-luminosity relation locates Hen 3-160 at the distance of about 9.4 kpc, and its Galactic coordinates ($l=267.7^{\circ}$, $b=-7.9^{\circ}$) place it $\sim$1.3 kpc above the disc. This position combined with relatively high proper motions (pm$_{\rm{RA}}=-1.5$ mas yr$^{-1}$, pm$_{\rm{DEC}}=+2.9$ mas yr$^{-1}$, Gaia DR2) indicates that Hen 3…
We present here the detailed optical and infra-red photometric analysis of the open star cluster IC 361. On studying the radial density profile, radial extent of the cluster is found to be 8.0 +/- 0.5 arcmin. The basic physical parameters of the cluster such as E(B-V) = 0.56 +/- 0.10 mag, E(V-K) = 1.72+/-0.12 mag, log(Age)=9.10+/-0.05, and (m-M)0 = 12.54 +/-.05 mag are obtained using the color-color and color-magnitude diagrams. IC 361 is found to be located at a distance of 3.22 +/- 0.07 kpc. Using the archival proper motion catalogues, we estimate mean proper motions of IC 361 as 4.97+/-0.17…
Analysis of the Gaia DR3 planetary nebula candidates and the possible symbiotic stars among them
Southern Spectroscopic Project Observatory Team (2SPOT)（南方光谱项目观测团队（2SPOT））；Astronomical Institute of Charles University（查理大学天文研究所）；Instituto de Astrofísica de Canarias（加那利群岛天体物理研究所）
We present a study of 7 southern open clusters based on UBVRI CCD photomety (Johnsons-Cousins system) and Gaia DR2 data. Dias 4, Dias 6 and four other clusters had UBVRI photometric observations determined for the first time. From the observational UBVRI data we obtained photometric membership probability estimates and, using the proper motions from the UCAC5 catalog, we also determined the kinematic membership. From Gaia DR2 astrometric data we determine the stellar membership using proper motions and parallaxes, taking into account the full covariance matrix. For both independent sets of dat…
The VISTA Magellanic Cloud (VMC) survey is assembling a deep, multi-epoch atlas of YJKs photometry across the Magellanic Clouds. Prior to the VMC survey only the brightest Magellanic Cloud PNe (MCPNe) were accessible at near-infrared (NIR) wavelengths. It is now possible for the first time to assemble the NIR properties of MCPNe and to identify contaminating non-PNe mimics which are best revealed at NIR wavelengths (e.g. HII regions and symbiotic stars). To maintain the unique scientific niche that MCPNe occupy these contaminants must be removed. Here we conduct a VMC-led, multi-wavelength stu…
The variable stars in the VSX catalog are derived from a multitude of inhomogeneous data sources and classification tools. This inhomogeneity complicates our understanding of variable star types, statistics, and properties, and it directly affects attempts to build training sets for current (and next) generation all-sky, time-domain surveys. We homogeneously analyze the ASAS-SN V-band light curves of ${\sim}412,000$ variables from the VSX catalog. The variables are classified using an updated random forest classifier with an $F_1$ score of 99.4\% and refinement criteria for individual classifi…
The binary fractions of open and globular clusters yield powerful constraints on their dynamical state and evolutionary history. We apply publicly available Bayesian analysis code to a $UBVRIJHK_{S}$ photometric catalog of the old open cluster NGC 188 to detect and characterize photometric binaries along the cluster main sequence. This technique has the advantage that it self-consistently handles photometric errors, missing data in various bandpasses, and star-by-star prior constraints on cluster membership. Simulations are used to verify uncertainties and quantify selection biases in our anal…
(Shortened). In the era of large surveys and space missions, it is necessary to rely on large samples of well-characterized stars for inter-calibrating and comparing measurements from different sources. Among the most employed photometric systems, the Johnson-Kron-Cousins has been used for decades and for a large amount of important datasets. Using Gaia DR3 as a reference, as well as data from reddening maps, spectroscopic surveys, and variable stars monitoring surveys, we curated and characterized the widely used Landolt and Stetson collections of more than 200 000 secondary standards, removi…
