Search Publications
Comparative study of activity of the near-parabolic orbitcomet C/1977 R1 (Kohler)
de Almeida, A. A.; Sanzovo, G. C.; de Araújo, L. F.
Kohler is considered a case of young, nearly parabolic comet. In this work we deduce, semi-empirically, water and hydroxyl production rates from the photometric observations of this comet taken from the Archive of Photometric Data on Comets and British Astronomical Society archives. Our results are being compared with those obtained from radio obs…
The Orion luminosity/mass function revisited
Peña Ramírez, K.
I present an analysis of the luminosity/mass function of the largest groups identified towards the Orion Complex. Those groups were determined using spectroscopic and astrometric data from APOGEE-2 and Gaia DR2 by applying a hierarchical clustering algorithm to the six-dimensional stellar data. I used Gaussian mixture models to represent the sampl…
Evaluating `twin' parallaxes for binary stars
Jofré, P.; Samadi-Ghadim, A.
Employing Gaia DR2 stellar parallaxes, we tried to first evaluate how `twin parallaxes' are compared with Gaia parallaxes. In the meantime, we checked how different is the performance of twin/Gaia parallaxes for binary stars than for single stars. Our study on a sample of Gaia DR2-RAVE DR5 stars shows that for 70% of them, the twin parallaxes agre…
The preliminary orbit of the new massive binary HD 93249
Gamen, R.; Barbá, R.; Morrell, N. I. +1 more
The OWN Survey is a high-resolution spectroscopic monitoring of Southern O and WN-type stars, whose multiplicity status is unknown. This project started more than ten years ago and it has discovered an important number of new binaries and other multiple systems. In this context, we present the first spectroscopic orbit of HD~93249, the brightest m…
Embedded clusters: upgrading visual and infrared photometric analysis with Gaia DR2 and ASteCA
Perren, G. I.; Vázquez, R. A.; Giorgi, E. E. +3 more
Embedded clusters are groups of stars which have not dispersed yet the residual of the parental cloud where they were born, thus getting precise distances and properties ofthese groups is an essential task. We present results for five embedded clusters: [DBS2003]5, [DBS2003]60, [DBS2003]98, [DBS2003]116 and [DBS2003]117, obtained from a combinatio…
Havlen-Moffat #1, el cúmulo menos pensado
Morrell, N. I.; Gamen, R. C.; Giorgi, E. E. +1 more
The cluster Havlen-Moffat # 1 (HM1), in the constellation of Scorpius, owes its name to those who discovered it in 1977. They identified, spectroscopically, two Wolf-Rayet and two Of-type stars. HM1 is located in the fourth quadrant of the Milky Way where the absorption of the interstellar medium is significant. This work presents an analysis of t…
STARHORSE photo-astrometricdistances, extinctions, and astrophysical parameters for Gaia DR2 stars
Anders, F.; Chiappini, C.; Santiago, B. X. +2 more
By combining the precise data delivered by Gaia DR2 with the photometric catalogues of PanSTARRS-1, 2MASS, and AllWISE, we recently derived Bayesian stellar parameters, distances, and extinctions for 265 million stars. The results are available to the community through the Gaia mirror at gaia.aip.de. We remind the community to pay attention to the…
Fractal dimension in star formation regions
Canavesi, T.; Hurtado, S.
Several two-dimensional studies in spiral galaxies show that HII star formation regions have a fractal distribution, with a fractal dimension of approximately 2.3. In this work, the fractal dimension is calculated through the box-counting method implemented in an R code. The innovation of the work lies in calculating the fractal dimension directly…
On the origin of stellar associations The impact of Gaia DR2
Carraro, G.
In this review I discuss different theories of the formation of OB associations in the Milky Way, and provide the observational evidences in support of them. In fact, the second release of Gaia astrometric data (April 2018) is revolutionising the field, because it allows us to unravel the 3D structure and kinematics of stellar associations with un…
Interacción entre el RSN G359.1-0.5 y el medio interestelar
Combi, J. A.; Eppens, L. K.; Reynoso, E. M. +1 more
G359.1-0.5 is a supernova remnant near the Galactic center region that belongs to the mixed morphology type, showing a radio continuum shell and diffuse thermal X-ray emission inside. Earlier molecular studies around the location of G359.1-0.5 revealed an annular CO structure in the velocity range from $-190$ to $-60~\rm{km} \rm{s}^{-1}$ with an H…