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Modeling and Calibration of Gaia, Hipparcos, and Tycho-2 astrometric data for the detection of dark companions
(2024-03-28)
Hidden within the Gaia satellite’s multiple data releases lies a valuable cache of dark companions. To facilitate the efficient and reliable detection of these companions via combined analyses involving the Gaia, Hipparcos, ...
Multiwavelength detection of an ongoing FUOr-type outburst on a low-mass YSO
(2024-03-01)
During the pre-main-sequence evolution, Young Stellar Objects (YSOs) assemble most of their mass during the episodic accretion process. The rarely seen FUOr-type events are valuable laboratories to investigate the outbursting ...
Predicting Cloud Conditions in Substellar Mass Objects Using Ultracool Dwarf Companions
(2024-02-29)
We present results from conducting a theoretical chemical analysis of a sample of benchmark companion brown dwarfs whose primary star is of type F, G or K. We summarize the entire known sample of these types of companion ...
Rapid Chemical Enrichment by Intermittent Star Formation in GN-z11
(2024-02-06)
We interpret the peculiar supersolar nitrogen abundance recently reported by the James Webb Space Telescope observations for GN-z11 (z = 10.6) using our state-of-the-art chemical evolution models. The observed CNO ratios ...
Long-period Radio Pulsars: Population Study in the Neutron Star and White Dwarf Rotating Dipole Scenarios
(2024-02-01)
The nature of two recently discovered radio emitters with unusually long periods of 18min (GLEAM-X J1627-52) and 21min (GPM J1839-10) is highly debated. Their bright radio emission resembles that of radio magnetars, but ...
Spectroscopic confirmation of high-amplitude eruptive YSOs and dipping giants from the VVV survey
(2024-02-01)
During the pre-main-sequence (pre-MS) evolution stage of a star, significant amounts of stellar mass are accreted during episodic accretion events, such as multidecade FUor-type outbursts. Here, we present a near-infrared ...
On the incidence of episodic accretion in Class I YSOs from VVV
(2024-02-01)
Episodic accretion is one of the competing models to explain the observed luminosity spread in young stellar clusters. These short-lived high accretion events could also have a strong impact on planet formation. Observations ...
The most variable VVV sources: eruptive protostars, dipping giants in the Nuclear Disc and others
(2024-02-01)
We have performed a comprehensive search of a VISTA Variables in the Via Lactea (VVV) data base of 9.5 yr light curves for variable sources with ΔKs ≥ 4 mag, aiming to provide a large sample of high amplitude eruptive young ...
Mitigating Modal Noise in Multimode Circular Fibres by Optical Agitation using a Galvanometer
(2024-01-02)
Modal noise appears due to the non-uniform and unstable distribution of light intensity among the finite number of modes in multimode fibres. It is an important limiting factor in measuring radial velocity precisely by ...
Ultracool Spectroscopic Outliers in Gaia DR3
(2024-01-01)
Gaia DR3 provided a first release of RP spectra and astrophysical parameters for ultracool dwarfs (UCDs). We used these Gaia RP spectra and astrophysical parameters to select the most outlying UCDs. These objects have ...