A massive open cluster hiding in full sight
arXiv:2104.08778 · doi:10.1093/mnras/stab1117
Abstract
Obscuration and confusion conspire to limit our knowledge of the inner Milky Way. Even at moderate distances, the identification of stellar systems becomes compounded by the extremely high density of background sources. Here we provide a very revealing example of these complications by unveiling a large, massive, young cluster in the Sagittarius arm that has escaped detection until now despite containing more than 30 stars brighter than . By combining Gaia DR2 astrometry, Gaia and 2MASS photometry and optical spectroscopy, we find that the new cluster, which we name Valparaiso~1, located at kpc, is about 75~Ma old and includes a large complement of evolved stars, among which we highlight the 4~d classical Cepheid CM~Sct and an M-type giant that probably represents the first detection of an AGB star in a Galactic young open cluster. Although strong differential reddening renders accurate parameter determination unfeasible with the current dataset, direct comparison to clusters of similar age suggests that Valparaiso~1 was born as one of the most massive clusters in the Solar Neighbourhood, with an initial mass close to M.
arXiv comment12 pages, 10 figures, accepted for publication in MNRAS
References in corpus (56)
- emcee: The MCMC Hammer
- Gaia Data Release 2. Summary of the contents and survey properties
- PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
- A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
- Gaia Early Data Release 3: The astrometric solution
- Young massive star clusters
- Gaia Data Release 2: using Gaia parallaxes
- A Gaia DR2 view of the Open Cluster population in the Milky Way
- Painting a portrait of the Galactic disc with its stellar clusters
- Gaia Data Release 3 Properties and validation of the radial velocities
- The Big Problems in Star Formation: the Star Formation Rate, Stellar Clustering, and the Initial Mass Function
- New Period-Luminosity and Period-Color Relations of Classical Cepheids: I. Cepheids in the Galaxy
- A Complete N-body Model of the Old Open Cluster M67
- A new calibration of Galactic Cepheid Period-Luminosity relations from B to K bands, and a comparison to LMC PL relations
- The mass function of young star clusters in spiral galaxies
- Gaia Data Release 2: Properties and validation of the radial velocities
- Hunting for open clusters in \textit{Gaia} DR2: new OCs in the Galactic disc
- Classical Cepheid Pulsation Models. X. The Period-Age Relation
- A reanalysis of the Gaia Data Release 2 photometric sensitivity curves using HST/STIS spectrophotometry
- A re-classification of Cepheids in the Gaia Data Release 2
- ASteCA - Automated Stellar Cluster Analysis
- Lithium and zirconium abundances in massive Galactic O-rich AGB stars
- Similarities in Populations of Star Clusters
- Cepheid Abundances: Multiphase Results and Spatial Gradients
- Rubidium, zirconium, and lithium production in intermediate-mass asymptotic giant branch stars
- The CFHT Open Star Cluster Survey. III. The White Dwarf Cooling Age of the Rich Open Star Cluster NGC 2099 (M37)
- Cygnus OB2 DANCe: A high precision proper motion study of the Cygnus OB2 association
- Internal dynamics and membership of the NGC 3603 Young Cluster from microarcsecond astrometry
- Cepheids in Open Clusters: An 8-D All-sky Census
- The Gaia-ESO Survey: Stellar content and elemental abundances in the massive cluster NGC 6705
- A representative sample of Be Stars I: Sample Selection, Spectral Classification and Rotational Velocities
- A massive association around the obscured open cluster RSGC3
- Consistent metallicity scale for cool dwarfs and giants. A benchmark test using the Hyades
- A search for counterparts to massive X-ray binaries using photometric catalogues
- An LTE effective temperature scale for red supergiants in the Magellanic clouds
- Near-infrared spectra of Galactic stellar clusters detected on Spitzer/GLIMPSE images
- Red supergiants around the obscured open cluster Stephenson 2
- NGC 6067: a young and massive open cluster with high metallicity
- Structure and stellar content analysis of the open cluster M11 with 2MASS photometry
- VdBH 222: a starburst cluster in the inner Milky Way
- Three open clusters containing Cepheids: NGC 6649, NGC 6664 and Berkeley 55
- Characterisation of red supergiants in the Gaia spectral range
- Clusterix 2.0. A Virtual Observatory tool to estimate cluster membership probability
- A revisited study of Cepheids in open clusters in the Gaia era
- On the mass of the Galactic star cluster NGC 4337
- A high-mass Planetary Nebula in a Galactic Open Cluster
- Berkeley 51, a young open cluster with four yellow supergiants
- Chandra X-ray Observatory and Hubble Space Telescope observations of the intermediate-age cluster GLIMPSE-C01
- New Cepheid variables in the young open clusters Berkeley 51 and Berkeley 55
- Which young clusters/associations are we missing today?
- The young open cluster Berkeley 55
- Cluster membership for the long period Cepheid calibrator SV Vul
- An obscured cluster associated with the HII region RCW173
- iSpec: An integrated software framework for the analysis of stellar spectra
- On the nature of VX Sagitarii: Is it a TZO, a RSG or a high-mass AGB star?
- The starbursts in the Milky Way
Cited by in corpus (4)
- SteParSyn: A Bayesian code to infer stellar atmospheric parameters using spectral synthesis
- OCCASO IV. Radial Velocities and Open Cluster Kinematics
- MAGIS (Measuring Abundances of red super Giants with Infrared Spectroscopy) project I. Establishment of an abundance analysis procedure for red supergiants and its evaluation with nearby stars
- Gaia colour-magnitude diagrams of young open clusters: Identification in the UBC catalogue and a comparison of manual and automated analysis