A5040501145- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Scientific Research and Discoveries
- Advanced Algorithms and Applications
- Geophysics and Gravity Measurements
- Advanced Measurement and Detection Methods
- Adaptive optics and wavefront sensing
- Astronomical and nuclear sciences
Universidad de Alcalá
2024
Centro de Astrobiología
2010-2021
Universidad Autónoma de Madrid
2021
Trinity House
2014
Isaac Newton Group
2010-2011
Isaac Newton Institute
2010
IPHASX J194359.5+170901 is a new high-excitation planetary nebula with remarkable characteristics. It consists of knotty ring expanding at speed 28 km s−1, and fast collimated outflow in the form faint lobes caps along direction perpendicular to ring. The expansion polar ∼100 their kinematical age twice as large Time-resolved photometry central star reveals sinusoidal modulation period 1.16 d. This interpreted evidence for binarity star, brightness variations being related orbital motion an...
The Hubble Space Telescope has devoted 500 orbits to observing 250 massive stars with low metallicity in the ultraviolet (UV) range within framework of ULLYSES program. X-Shooting (XShootU) project enhances legacy value this UV dataset by providing high-quality optical and near-infrared spectra, which are acquired using wide-wavelength-coverage X-shooter spectrograph at ESO's Very Large Telescope. XShootU emphasises importance combining spectra for consistent determination key stellar...
We report on the discovery of ETHOS 1 (PN G068.1+11.0), first spectroscopically confirmed planetary nebula (PN) from a survey SuperCOSMOS Science Archive for high-latitude PNe. stands out as one few PNe to have both polar outflows (jets) travelling at 120 ± 10 km s−1 and close binary central star. The light curve observed with Mercator Telescope reveals an orbital period 0.535 d extremely large amplitude (0.816 mag) due irradiation companion by very hot pre-white dwarf. further strengthens...
We present time-resolved optical spectroscopy of V458 Vulpeculae (Nova Vul 2007 No. 1) spread over a period 15 months starting 301 days after its discovery. Our data reveal radial velocity variations in the HeII {\lambda}5412 and {\lambda}4686 emission lines. A analysis curves resulted 98.09647 \pm 0.00025 min (0.06812255 0.00000017 d) which we identify with orbital binary system. is therefore planetary nebula central star shortest known. explore possibility system being composed relatively...
Context. The IPHAS Hα survey provides a rich database to search for emission-line sources in the northern Galactic plane.
We present the first detailed spatiokinematical analysis and modelling of planetary nebula Abell 41, which is known to contain well-studied close-binary system MT Ser. This object represents an important test case in study evolution nebulae with binary central stars as current evolutionary theories predict that plane should be aligned perpendicular symmetry axis nebula. Deep narrow-band imaging light [N ii] 6584 Å, [O iii] 5007 Å [S 6717+6731 obtained using ACAM on William Herschel...
We have identified two new near-infrared emission lines in the spectra of planetary nebulae (PNe) arising from heavy elements produced by neutron capture reactions: [Te III] 2.1019 $\mu$m and [Br V] 1.6429 $\mu$m. was detected both NGC 7027 IC 418, while seen 7027. The observations were obtained with medium-resolution spectrograph EMIR on 10.4m Gran Telescopio Canarias at La Palma, high-resolution IGRINS 2.7m Harlan J. Smith telescope McDonald Observatory. New calculations atomic data for...
We probe the radial clumping stratification of OB stars in intermediate and outer wind regions (r>~2 R*) to derive upper limits for mass-loss rates, compare current implementation. Together with archival multi-wavelength data, our new far-infrared continuum observations a sample 25 (including 13 B Supergiants) uniquely constrain properties region. minimum factor through stellar wind, fclmin(r), corresponding maximum rate, Mdotmax, normalising factors outermost region (clfar=1). The degree...
We present a detailed study of the binary central star planetary nebula ETHOS 1 (PN G068.1+11.0). Simultaneous modelling light and radial velocity curves reveals to comprise hot massive pre-white-dwarf with an M-type main-sequence companion. A good fit observations was found companion that follows expected mass-temperature-radius relationships for low-mass stars, indicating despite being highly irradiated it is consistent not significantly hotter or larger than typical same mass. Previous...
Our long-term photometric monitoring of southern nova-like cataclysmic variables with the 1.3-m Small and Moderate Aperture Research Telescope System (SMARTS) telescope found BB Doradus fading from V∼ 14.3 towards a deep low state at 19.3 in 2008 April. Here we present time-resolved optical spectroscopy Dor this faint 2009. The spectrum quiescence is composite hot white dwarf Teff= 30 000 ± 5000 K M3–M4 secondary star narrow emission lines (mainly Balmer series He i) superposed. We associate...
A thorough search of the OGLE-III microlensing project has more than doubled total sample PNe known to have close binary central stars. These discoveries enabled induced morphological trends be revealed for first time. Canonical bipolar nebulae, low-ionisation structures and polar outflows are all identified within provisionally associated with binarity. We embarked upon a large photometric monitoring program using Flemish Mercator telescope simultaneously test predictive power these...
The link between the shaping of bipolar planetary nebulae and their central stars is still poorly understood. kinematics multipolar nebula M 1-75 are hereby investigated, location nature its star briefly discussed. Fabry-Perot data from GHaFAS on WHT sampling Doppler shift [N II] 658.3 nm line used to study dynamics nebula, by means a detailed 3-D spatio-kinematical model. Multi-wavelength images spectra WFC IDS INT, ACAM WHT, allowed us constrain parameters star. two pairs lobes, angularly...
<i>Aims. <i/>Eleven new symbiotic stars have recently been discovered with IPHAS, the INT H<i>α<i/> survey of Northern Galactic plane. The star IPHAS J190832.31+051226.6 was proposed as an additional candidate on basis existing spectrum. Here, we investigate nature this source by means observations.<i>Methods. <i/>Photometric data, optical spectra obtained in 2006 and 2009, a higher resolution spectrum resolving profile, near-IR are all presented.<i>Results. <i/>The brightened <i>r<i/> band...
Close binarity can play a significant role in the shaping of planetary nebulae (PNe) as system evolves through common-envelope phase. We present detection two shortest orbital periods among PN binary central stars. These are Hen 2-428, bipolar PN, and V458 Vul, recent nova surrounded by mildly nebula. The properties stars these systems, their possible fate discussed.
Abstract Mass-loss is a key parameter throughout the evolution of massive stars. In this work we probe radial clumping stratification OB stars in intermediate and outer wind regions ( r ≳ 2 R * ; , distance to photosphere), derive upper limits for mass-loss rates, Ṁ max compare them current theoretical recipes implemented evolutionary models. A conclusion our analysis regards derived upper-limit rates B supergiants, independently clumping, which calls an urgent revision role recombination...
Using the medium resolution spectrograph X-shooter, spectra of 235 OB and Wolf-Rayet (WR) stars in sub-solar metallicity environments have been secured. [...]This second paper focuses on optical observations 232 Magellanic Clouds targets. It describes uniform reduction UVB (300 - 560 nm) VIS (550 1020 XShootU data as well preparation advanced products [...] . The raw is based ESO CPL X-shooter pipeline. We paid particular attention to determination response curves implemented slit-loss...
Abstract Recent studies of WNh stars at the cores young massive clusters have challenged previously accepted upper stellar mass limit (~150 M ⊙ ), suggesting some these objects may initial masses as high 300 . We investigated possible existence observed above ~150 by i) examining nature and properties VFTS 682, a recently identified WNh5 very star, ii) studying uncertainties in luminosity estimates R136’s core due to crowding. Our spectroscopic analysis reveals that most members R136 682 are...
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Abstract At present, it is well established that previously accepted mass-loss rates ( Ṁ ) of luminous OB stars may be overestimated when clumping neglected. Our Herschel/PACS Far-Infrared (Far-IR) observations a set allow us to improve our knowledge stratification, constraining properties in intermediate wind regions. In this work, better sampled structure estimates are provided for ι Ori, ε Ori and ξ Per as an initial estimate the from τ Sco. These will obtain reliable understanding physics.
Abstract We present a pilot study of using the Atacama Large Millimeter/sub-millimeter Array (ALMA) continuum observations to constrain density structure in intermediate wind zone massive stars, which is extremely sensitive clumping.