General
The research that is being carried out by the group can be condensed into two main lines:
1) Study of the structure, dynamics, physical conditions and chemical evolution of Galactic and extragalactic ionized nebulae through detailed analysis and modelization of their spectra. Investigation of chemical composition gradients along the disk of our Galaxy and in nearby galaxies.
2) Determine the physical-chemical conditions of galactic planetary nebulae with bipolar geometry and nebulae around symbiotic stars. The aim is to understand the origin of bipolarity and to test theoretical models that attempt to explain nebular morphology and kinematics, with special emphasis on models with central binary stars. We will also study the implications of the evolution of binary systems in other astrophysical scenarios, such as the formation of jets, cataclysmic variables, and nova and supernova-type explosions.
Members
Results
- Using EMIR/GTC spectra in the near infrared range, tellurium and bromine emission lines have been detected for the first time in two planetary nebulae. These heavy element detections in one of their places where they are formed, give us information about the abundance patterns of heavy elements owing to the r-process and the s-process.
Scientific activity
Related publications
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Atomic Data Assessment with PyNeb
PyNeb is a Python package widely used to model emission lines in gaseous nebulae. We take advantage of its object-oriented architecture, class methods, and historical atomic database to structure a practical environment for atomic data assessment. Our aim is to reduce the uncertainties in parameter space (line-ratio diagnostics, electron density
Morisset, Christophe et al.Advertised on:
102020 -
A plague of magnetic spots among the hot stars of globular clusters
For more than six decades, the quest to understand the formation of hot (about 20,000-30,000 K) extreme horizontal branch (EHB) stars in Galactic globular clusters has remained one of the most elusive in stellar evolutionary theory. Here we report on two discoveries that challenge the idea of the stable luminosity of EHB stars. The first mode of
Momany, Y. et al.Advertised on:
62020 -
Physics of Eclipsing Binaries. V. General Framework for Solving the Inverse Problem
PHOEBE 2 is a Python package for modeling the observables of eclipsing star systems, but until now it has focused entirely on the forward model—that is, generating a synthetic model given fixed values of a large number of parameters describing the system and the observations. The inverse problem, obtaining orbital and stellar parameters given
Conroy, Kyle E. et al.Advertised on:
102020 -
The post-common-envelope binary central star of the planetary nebula PN G283.7-05.1. A possible post-red-giant-branch planetary nebula central star
We present the discovery and characterisation of the post-common-envelope central star system in the planetary nebula PN G283.7-05.1. Deep images taken as part of the POPIPlaN survey indicate that the nebula may possess a bipolar morphology similar to other post-common-envelope planetary nebulae. Simultaneous light and radial velocity curve
Jones, D. et al.Advertised on:
102020 -
The post-common-envelope binary central star of the planetary nebula ETHOS 1
We present a detailed study of the binary central star of the planetary nebula ETHOS 1 (PN G068.1+11.0). Simultaneous modelling of light and radial velocity curves reveals the binary to comprise a hot and massive pre-white dwarf with an M-type main-sequence companion. A good fit to the observations was found with a companion that follows expected
Munday, James et al.Advertised on:
92020 -
A study of extragalactic planetary nebulae populations based on spectroscopy. I. Data compilation and first findings
We compile published spectroscopic data and [O III] magnitudes of almost 500 extragalactic planetary nebulae (PNe) in 13 galaxies of various masses and morphological types. This is the first paper of a series that aims to analyse the PN populations and their progenitors in these galaxies. Although the samples are not complete or homogeneous, we
Delgado-Inglada, G. et al.Advertised on:
92020 -
Abell 30 - A binary central star among the born-again planetary nebulae
Eight planetary nebulae have been identified as 'born-again', a class of object typified by knotty secondary ejecta having low masses (${\sim}10^{-4}$ M ☉) with nearly no hydrogen. Abell 30, the archetype of the class, also belongs to a small subset of planetary nebulae that exhibit extreme abundance discrepancy factors (where Abell 30 is the most
Jacoby, George H. et al.Advertised on:
82020 -
The impact of strong recombination on temperature determination in planetary nebulae
The long-standing difference in chemical abundances determined from optical recombination lines and collisionally excited lines raises questions about our understanding of atomic physics, as well as the assumptions made when determining physical conditions and chemical abundances in astrophysical nebulae. Here, we study the recombination
Gómez-Llanos, V. et al.Advertised on:
72020 -
The Galactic radial abundance gradients of C, N, O, Ne, S, Cl, and Ar from deep spectra of H II regions
We present a reassessment of the radial abundance gradients of C, N, O, Ne, S, Cl, and Ar in the Milky Way using deep spectra of 33 H II regions gathered from the literature, covering Galactocentric distances from 6 to 17 kpc. The distances of the objects have been revised using Gaia parallaxes. We recalculate the physical conditions and ionic
Arellano-Córdova, K. Z. et al.Advertised on:
62020 -
Tidally trapped pulsations in a close binary star system discovered by TESS
It has long been suspected that tidal forces in close binary stars could modify the orientation of the pulsation axis of the constituent stars. Such stars have been searched for, but until now never detected. Here we report the discovery of tidally trapped pulsations in the ellipsoidal variable HD 74423 in Transiting Exoplanet Survey Satellite
Handler, G. et al.Advertised on:
32020 -
Helium abundances and its radial gradient from the spectra of H II regions and ring nebulae of the Milky Way
We determine the radial abundance gradient of helium in the disc of the Galaxy from published spectra of 19 H II regions and ring nebulae surrounding massive O-type stars. We revise the Galactocentric distances of the objects considering Gaia DR2 parallaxes (Gaia Collaboration 2018) and determine the physical conditions and the ionic abundance of
Méndez-Delgado, J. E. et al.Advertised on:
62020 -
IGAPS: the merged IPHAS and UVEX optical surveys of the northern Galactic plane
The INT Galactic Plane Survey (IGAPS) is the merger of the optical photometric surveys, IPHAS and UVEX, based on data from the Isaac Newton Telescope (INT) obtained between 2003 and 2018. Here, we present the IGAPS point source catalogue. It contains 295.4 million rows providing photometry in the filters, i, r, narrow-band Hα, g, and U RGO. The
Monguió, M. et al.Advertised on:
62020 -
The single-sided pulsator CO Camelopardalis
CO Cam (TIC 160268882) is the second 'single-sided pulsator' to be discovered. These are stars where one hemisphere pulsates with a significantly higher amplitude than the other side of the star. CO Cam is a binary star comprised of an Am δ Sct primary star with T eff = 7070 ± 150 K, and a spectroscopically undetected G main-sequence secondary star
Kurtz, D. W. et al.Advertised on:
42020 -
AT 2019abn: multi-wavelength observations over the first 200 days
Context. AT 2019abn was discovered in the nearby M51 galaxy by the Zwicky Transient Facility at more than two magnitudes and around three weeks prior to its optical peak. Aims: We aim to conduct a detailed photometric and spectroscopic follow-up campaign for AT 2019abn, with early discovery allowing for significant pre-maximum observations of an
Williams, S. C. et al.Advertised on:
52020 -
Physics of Eclipsing Binaries. IV. The Impact of Interstellar Extinction on the Light Curves of Eclipsing Binaries
Traditionally, the effects of interstellar extinction on binary star light curves have been treated as a uniform reduction in the observed brightness of the system that is independent of the orbital phase. However, unless the orbital plane of the system coincides with the plane of the sky, or if the two stars are completely identical and present
Jones, David et al.Advertised on:
42020 -
Planetary nebulae seen with TESS: Discovery of new binary central star candidates from Cycle 1
Context. It has become clear in recent years that binarity plays a crucial role in many aspects of planetary nebulae (PNe), particularly with regard to the striking morphologies they exhibit. To date, there are nearly 60 known binary central stars of PNe (bCSPNe). However, both theory and observation indicate that this figure represents only the
Aller, A. et al.Advertised on:
32020 -
Ondřejov Echelle Spectrograph, Ground Based Support Facility for Exoplanet Missions
Fulfilling the goals of space-based exoplanetary transit surveys, like Kepler and TESS, is impossible without ground-based spectroscopic follow-up. In particular, the first-step vetting of candidates could easily necessitate several hundreds of hours of telescope time—an area where 2 m class telescopes can play a crucial role. Here, we describe the
Kabáth, P. et al.Advertised on:
32020 -
Carbon, nitrogen, and oxygen abundance gradients in M101 and M31
We present deep spectrophotometry of 18 H II regions in the nearby massive spiral galaxies M 101 and M 31. We have obtained direct determinations of electron temperature in all the nebulae. We detect the C II 4267 Å line in several H II regions, permitting to derive the radial gradient of C/H in both galaxies. We also determine the radial gradients
Esteban, C. et al.Advertised on:
12020 -
On the triple-star origin of the planetary nebula Sh 2-71
Recent studies have indicated that triple-star systems may play a role in the formation of an appreciable number of planetary nebulae, however, only one triple central star is known to date (and that system is likely too wide to have had much influence on the evolution of its component stars). Here, we consider the possibility that Sh 2-71 was
Jones, David et al.Advertised on:
102019 -
First Evidence of Enhanced Recombination in Astrophysical Environments and the Implications for Plasma Diagnostics
We report the first unambiguous observational evidence of Rydberg Enhanced Recombination (RER), a potentially important recombination mechanism that has hitherto been unexplored in low-temperature photoionized plasmas. RER shares similarities with dielectronic recombination, with the difference that the electron is captured into a highly excited
Nemer, A. et al.Advertised on:
122019