scholarly journals The visible and near-infrared spectra of asteroids in cometary orbits

2018 ◽  
Vol 618 ◽  
pp. A170 ◽  
Author(s):  
J. Licandro ◽  
M. Popescu ◽  
J. de León ◽  
D. Morate ◽  
O. Vaduvescu ◽  
...  
Keyword(s):  
Near Infrared ◽  
Spectral Slope ◽  
Isaac Newton ◽  
Infrared Telescope ◽  
La Palma ◽  
Spectral Class ◽  
Telescope Facility ◽  
Hydrated Minerals ◽  
Taxonomical Classification ◽  
William Herschel

Context. Dynamical and albedo properties suggest that asteroids in cometary orbits (ACOs) are dormant or extinct comets. Their study provides new insights for understanding the end-states of comets and the size of the comet population. Aims. We intend to study the visible and near-infrared (NIR) spectral properties of different ACO populations and compare them to the independently determined properties of comets. Methods. We select our ACOs sample based on published dynamical criteria and present our own observational results obtained using the 10.4 m Gran Telescopio Canarias (GTC), the 4.2 m William Herschel Telescope (WHT), the 3.56 m Telescopio Nazionale Galileo (TNG), and the 2.5 m Isaac Newton Telescope (INT), all located at the El Roque de los Muchachos Observatory (La Palma, Spain), and the 3.0 m NASA Infrared Telescope Facility (IRTF), located at the Mauna Kea Observatory, in Hawaii. We include in the analysis the spectra of ACOs obtained from the literature. We derive the spectral class and the visible and NIR spectral slopes. We also study the presence of hydrated minerals by studying the 0.7 μm band and the UV-drop below 0.5 μm associated with phyllosilicates. Results. We present new observations of 17 ACOs, 11 of them observed in the visible, 2 in the NIR and 4 in the visible and NIR. We also discuss the spectra of 12 ACOs obtained from the literature. All but two ACOs have a primitive-like class spectrum (X or D-type). Almost 100% of the ACOs in long-period cometary orbits (Damocloids) are D-types. Those in Jupiter family comet orbits (JFC-ACOs) are ∼60% D-types and ∼40% X-types. The mean spectral slope S′ of JFC-ACOs is 9.7 ± 4.6%/1000 Å and for the Damocloids this is 12.2 ± 2.0%/1000 Å. No evidence of hydration on the surface of ACOs is found from their visible spectra. The spectral slope and spectral class distribution of ACOs is similar to that of comets. Conclusions. The spectral taxonomical classification and the spectral slope distribution of ACOs, and the lack of spectral features indicative of the presence of hydrated minerals on their surface, strongly suggest that ACOs are likely dormant or extinct comets.

Compositional characterization of V-type candidate asteroids identified using the MOVIS catalogue

2019 ◽  
Vol 488 (3) ◽  
pp. 3866-3875 ◽  
Author(s):  
H Medeiros ◽  
J de León ◽  
D Lazzaro ◽  
M Popescu ◽  
V Lorenzi ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Spectral Parameters ◽  
Optical Telescope ◽  
Isaac Newton ◽  
Infrared Telescope ◽  
Band Area ◽  
La Palma ◽  
Near Infrared Spectra ◽  
The Right

ABSTRACT The main objective of this work is to compositionally analyse the visible to near-infrared spectra of a total of six V-type candidates identified using the MOVIS (Y-J) versus (J-Ks) colour–colour plot and located outside the Vesta collisional family. We obtained visible and near-infrared spectra of these asteroids using the 2.54m Isaac Newton Telescope, the 2.5m Nordic Optical Telescope, and the 3.58m Telescopio Nazionale Galileo, all located at the El Roque de Los Muchachos Observatory (La Palma, Spain), as well as the 3.0m NASA Infrared Telescope Facility, located at the Mauna Kea Observatory in Hawaii. We computed several diagnostic spectral parameters (slopes, band centres, band depths, band area ratio, or BAR) and compared them to the ones known for HED meteorites and (4) Vesta. The taxonomic classification confirmed five out of the six candidates as V-types, leading to an identification success rate about 83 per cent. In general, the spectral parameters obtained for the five V-types are in good agreement with those of HED meteorites and (4) Vesta. The exception is asteroid (2452) Lyot, a V-type in the outer belt, located very close to (1459) Magnya, but showing distinct [Wo] and [Fs] molar contents both from Magnya and Vesta, pointing toward a diogenitic compostion. We also studied the dependency of the BAR parameter on the way it is computed (removing or not the continuum), the spectral slope, and the last point used to delimit the right wing of the absorption band at 2 μm.

scholarly journals The La Palma Data Archive

1989 ◽  
Vol 110 ◽  
pp. 139-140
Author(s):  
Chris Benn
Keyword(s):  
Data Archive ◽  
Isaac Newton ◽  
La Palma ◽  
Data Archives ◽  
International Ultraviolet Explorer ◽  
Isaac Newton Telescope ◽  
The Republic ◽  
Volcanic Caldera ◽  
The Uk ◽  
William Herschel

The Observatorio del Roque de los Muchachos is perched atop a volcanic caldera on the island of La Palma in the Canary Islands, 400 km off the coast of North Africa. Three of the telescopes at the observatory are products of a collaboration between the UK, the Netherlands, Spain and the Republic of Ireland. They are the 1.0-m Jacobus Kapteyn Telescope, the 2.5-m Isaac Newton Telescope and the 4.2-m William Herschel Telescope (which saw first light in July 1987)1. The telescopes are computer controlled (running under ADAM software), and the observations are recorded primarily in electronic form. Recognising the success of astronomical-satellite data archives, such as that generated by the International Ultraviolet Explorer, a La Palma Data Archive has been established at the Royal Greenwich Observatory. The archive will be used by astronomers wishing to exploit data obtained by other observers, by engineers interested in the performance of telescope and instruments under varying conditions, and for monitoring the way in which the telescope is used.

scholarly journals The Near-Infrared Capabilities of LEST

1994 ◽  
Vol 154 ◽  
pp. 579-588
Author(s):  
Oddbjørn Engvold
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Tracking System ◽  
Entrance Window ◽  
La Palma ◽  
System A ◽  
Near Ir ◽  
Telescope Facility ◽  
Main Mirror ◽  
Ir Instrumentation

The Large Earth-based Solar Telescope (LEST) will be a powerful, next-generation telescope with unprecedented angular resolution, capable of highly accurate polarimetry of the Sun, covering the optical spectral range from about 300 nm into the near infrared to about 2.5 μm.The telescope is a 2.4-m aperture, “polarization-free” concept based on a modified Gregorian optical system. A fast polarization modulator will be located close to the secondary focus of the system. An actively controlled NTT-type main mirror, a high precision pointing and tracking system, a helium-filled light path and a thin entrance window, together with an integrated adaptive optics system, will give the telescope near diffraction-limited performance in the visible. LEST will be sited on La Palma, in the Canary Islands, near the caldera rim on the Roque de los Muchachos Observatory, which often offers excellent seeing. A frequently occurring seeing parameter of ro = 15–20 cm in the visible will correspond to ro ≥ 1 m in the near IR.The construction of LEST will begin in 1993, and the telescope is to be ready for “first light” in 1997. The telescope facility will accommodate a large number of focal plane instruments on a spacious instrument table. LEST will be made available for near-IR instrumentation from the start of its regular operation.

scholarly journals Characterization of material around the centaur (2060) Chiron from a visible and near-infrared stellar occultation in 2011

2019 ◽  
Vol 491 (3) ◽  
pp. 3643-3654
Author(s):  
A A Sickafoose ◽  
A S Bosh ◽  
J P Emery ◽  
M J Person ◽  
C A Zuluaga ◽  
...  
Keyword(s):  
Near Infrared ◽  
Detailed Examination ◽  
Optical Data ◽  
Infrared Telescope ◽  
Nir Light ◽  
Spherical Diameter ◽  
Telescope Facility ◽  
Nasa Infrared Telescope Facility ◽  
Scattering Material

ABSTRACT The centaur (2060) Chiron exhibits outgassing behaviour and possibly hosts a ring system. On 2011 November 29, Chiron occulted a fairly bright star (R ∼ 15 mag) as observed from the 3-m NASA Infrared Telescope Facility (IRTF) on Mauna Kea and the 2-m Faulkes Telescope North (FTN) at Haleakala. Data were taken as visible wavelength images and simultaneous, low-resolution, near-infrared (NIR) spectra. Here, we present a detailed examination of the light-curve features in the optical data and an analysis of the NIR spectra. We place a lower limit on the spherical diameter of Chiron's nucleus of 160.2 ± 1.3 km. Sharp, narrow dips were observed between 280 and 360 km from the centre (depending on event geometry). For a central chord and assumed ring plane, the separated features are 298.5–302 and 308–310.5 km from the nucleus, with normal optical depth ∼0.5–0.9, and a gap of 9.1 ± 1.3 km. These features are similar in equivalent depth to Chariklo's inner ring. The absence of absorbing/scattering material near the nucleus suggests that these sharp dips are more likely to be planar rings than a shell of material. The region of relatively increased transmission is within the 1:2 spin-orbit resonance, consistent with the proposed clearing pattern for a non-axisymmetric nucleus. Characteristics of possible azimuthally incomplete features are presented, which could be transient, as well as a possible shell from ∼900–1500 km: future observations are needed for confirmation. There are no significant features in the NIR light curves, nor any correlation between optical features and NIR spectral slope.

scholarly journals Optical validation and characterisation of Planck PSZ1 sources at the Canary Islands observatories

2020 ◽  
Vol 638 ◽  
pp. A146
Author(s):  
R. Barrena ◽  
A. Ferragamo ◽  
J. A. Rubiño-Martín ◽  
A. Streblyanska ◽  
A. Aguado-Barahona ◽  
...  
Keyword(s):  
Galaxy Clusters ◽  
Gaussian Noise ◽  
Velocity Dispersion ◽  
Thermal Emission ◽  
Isaac Newton ◽  
La Palma ◽  
Second Year ◽  
Imaging And Spectroscopy ◽  
Non Gaussian ◽  
William Herschel

We report new galaxy clusters previously unknown included in the first Planck Sunyaev–Zeldovich (SZ) sources catalogue, the PSZ1. The results presented here were achieved during the second year of a two-year observational programme, the ITP13, developed at the Roque de los Muchachos Observatory (La Palma, Spain). Using the 2.5 m Isaac Newton telescope, the 3.5 m Telescopio Nazionale Galileo, the 4.2 m William Herschel telescope and the 10.4 m Gran Telescopio Canarias we characterised 75 SZ sources with low SZ significance, SZ S/N <  5.32. We performed deep optical imaging and spectroscopy in order to associate actual galaxy clusters with the SZ Planck source. We adopted robust criteria, based on the 2D spatial distribution, richness, and velocity dispersions to confirm actual optical counterparts up to z <  0.85. The selected systems are confirmed only if they are well aligned with respect to the PSZ1 coordinate and show high richness and high velocity dispersion. In addition, we also inspected the Compton y-maps and SZ significance in order to identify unrealistic detections. Following this procedure, we identify 26 cluster counterparts associated with the SZ emission, which means that only about 35% of the clusters considered in this low S/N PSZ1 subsample are validated. Forty-nine SZ sources (∼65% of this PSZ1 subset) remain unconfirmed. At the end of the ITP13 observational programme, we have studied 256 SZ sources with Dec ≥ −15° (212 of them completely unknown), finding optical counterparts for 152 SZ sources. The ITP13 validation programme has allowed us to update the PSZ1 purity, which is now more refined, increasing from 72% to 83% in the low SZ S/N regime. Our results are consistent with the predicted purity curve for the full PSZ1 catalogue and with the expected fraction of false detections caused by the non-Gaussian noise of foreground signals. We find a strong correlation between the number of unconfirmed sources and the thermal emission of diffuse galactic dust at 857 GHz, thus increasing the fraction of false Planck SZ detections at low galactic latitudes.

scholarly journals Ultraviolet to Near Infrared Observations of BF Cyg

1988 ◽  
Vol 103 ◽  
pp. 301-302
Author(s):  
A. Cassatella ◽  
R. Gonzalez-Riestra ◽  
T. Fernandez-Castro ◽  
J. Fuensalida ◽  
A. Gimenez
Keyword(s):  
Canary Islands ◽  
Near Infrared ◽  
Single Channel ◽  
Photon Counting ◽  
Optical Observations ◽  
Counting System ◽  
Infrared Observations ◽  
Isaac Newton ◽  
Preliminary Results ◽  
La Palma

In this paper we provide preliminary results of multifrequency observations of BF Cyg carried out in July 1986. The ultraviolet spectra were obtained on July 26, 1986 using the IUE satellite. The optical observations were made at the Observatorio del Roque de los Muchachos (La Palma, Canary Islands) in July 1986 during the night 13/14 using the Isaac Newton 2.5m telescope with the Intermediate Dispersion Spectrograph (IDS, 500 mm camera) and the Image Photon Counting System (IPCS). The infrared observations were made during the night 13/14 of July, 1986, at the Observatorio del Teide (Tenerife, Canary Islands) using the Carlos Sanchez 1.5m telescope and an infrared single-channel photometer with an InSb detector.

Near-infrared arrays for SIRTF, the Space Infrared Telescope Facility

1993 ◽  
Author(s):  
William J. Forrest ◽  
Hao Chen ◽  
James D. Garnett ◽  
Steven L. Solomon ◽  
Judith L. Pipher
Keyword(s):  
Near Infrared ◽  
Infrared Telescope ◽  
Infrared Arrays ◽  
Telescope Facility ◽  
Infrared Telescope Facility

scholarly journals Precise Near-Infrared Radial Velocities

2015 ◽  
Vol 10 (S314) ◽  
pp. 286-287
Author(s):  
Peter Plavchan ◽  
Peter Gao ◽  
Jonathan Gagne ◽  
Elise Furlan ◽  
Carolyn Brinkworth ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Near Infrared ◽  
M Dwarfs ◽  
Gas Cell ◽  
Methane Absorption ◽  
Infrared Telescope ◽  
Telescope Facility ◽  
Nasa Infrared Telescope Facility ◽  
Modeling Code

AbstractWe present the results of two 2.3 μm near-infrared (NIR) radial velocity (RV) surveys to detect exoplanets around 36 nearby and young M dwarfs. We use the CSHELL spectrograph (R ~ 46,000) at the NASA InfraRed Telescope Facility (IRTF), combined with an isotopic methane absorption gas cell for common optical path relative wavelength calibration. We have developed a sophisticated RV forward modeling code that accounts for fringing and other instrumental artifacts present in the spectra. With a spectral grasp of only 5 nm, we are able to reach long-term radial velocity dispersions of ~20–30 m s−1 on our survey targets.

scholarly journals The H 3 + ionosphere of Uranus: decades-long cooling and local-time morphology

2019 ◽  
Vol 377 (2154) ◽  
pp. 20180408 ◽  
Author(s):  
Henrik Melin ◽  
L. N. Fletcher ◽  
T. S. Stallard ◽  
S. Miller ◽  
L. M. Trafton ◽  
...  
Keyword(s):  
Local Time ◽  
Near Infrared ◽  
Molecular Ions ◽  
Upper Atmosphere ◽  
Infrared Observations ◽  
Infrared Telescope ◽  
Telescope Facility ◽  
Nasa Infrared Telescope Facility ◽  
Cooling Trend

The upper atmosphere of Uranus has been observed to be slowly cooling between 1993 and 2011. New analysis of near-infrared observations of emission from H 3 + obtained between 2012 and 2018 reveals that this cooling trend has continued, showing that the upper atmosphere has cooled for 27 years, longer than the length of a nominal season of 21 years. The new observations have offered greater spatial resolution and higher sensitivity than previous ones, enabling the characterization of the H 3 + intensity as a function of local time. These profiles peak between 13 and 15 h local time, later than models suggest. The NASA Infrared Telescope Facility iSHELL instrument also provides the detection of a bright H 3 + signal on 16 October 2016, rotating into view from the dawn sector. This feature is consistent with an auroral signal, but is the only of its kind present in this comprehensive dataset. This article is part of a discussion meeting issue ‘Advances in hydrogen molecular ions: H 3 + , H 5 + and beyond’.

Spectroscopic study of Ceres' collisional family candidate members: taxonomic classification and comparison to Ceres' surface.

2021 ◽  
Author(s):  
Fernando Tinaut-Ruano ◽  
Julia de Leon ◽  
Eri Tatsumi ◽  
Batiste Rousseau ◽  
Juan Luis Rizos
Keyword(s):  
Near Infrared ◽  
Asteroid Belt ◽  
Space Weathering ◽  
Spectral Slope ◽  
Dynamical Study ◽  
Royal Astronomical Society ◽  
La Palma ◽  
The Family ◽  
Visible Spectra ◽  
Main Asteroid Belt

&lt;p&gt;Despite the observed signs of large impacts on the surface of Ceres, there is no confirmed collisional family associated with this dwarf planet. Carruba et al. (2016) carried out a dynamical study in the &amp;#8216;pristine region&amp;#8217; of the main asteroid belt and proposed a sample of 156 asteroids as candidates to be members of a Ceres&amp;#8217; collisional family. Our main objective in this work is to study the spectral link between Ceres and a total of 14 observed asteroids among the family candidate samples proposed by Carruba et al. (2016) to explore their potential membership to the collisional family.&lt;/p&gt; &lt;p&gt;For this aim we obtained visible spectra of these 14 asteroids using the OSIRIS spectrograph at the 10.4m Gran Telescopio de Canarias (GTC), located at the El Roque de los Muchachos Observatory (La Palma, Spain), managed by the Instituto de Astrof&amp;#237;sica de Canarias (IAC). We reduced the raw images and extracted the spectra with a semi-automatic Python-based pipeline. After that, we computed spectral slopes in two different wavelength ranges: one in the visible (490-800 nm) and one in the visible-near-infrared (800-920 nm) to compare the obtained values with those in Ceres&amp;#8217; surface already Ncomputed by Rousseau et al. (2020) using the spectrometer onboard the NASA Dawn spacecraft.&lt;/p&gt; &lt;p&gt;We present the spectra and the taxonomy of 14 observed asteroids, their taxonomy, and calculated slopes. We concluded that only one asteroid could be compatible with an origin in a primitive collision at Ceres. We have also found a hydration band at 700 nm, also found in the surroundings of crater Occattor (Rizos et al. 2019). On the other hand, we have also found a relation between the spectral slope of the craters in Ceres&amp;#8217; surface and their age in both wavelength ranges. This behavior could be related to space weathering.&lt;/p&gt; &lt;p&gt;Exploring the sample as a whole, the variability in member&amp;#8217;s taxonomy and the differences in their spectral slopes makes us conclude that they cannot be considered as members of a collisional family of Ceres. However, the presence of a hydration band in one of the asteroids could be proof that such a family may have existed.&lt;/p&gt; &lt;p&gt;&amp;#160;&lt;/p&gt; &lt;p&gt;&amp;#160;&lt;/p&gt; &lt;p&gt;Bibliography:&lt;/p&gt; &lt;p&gt;Carruba, V., Nesvorn&amp;#253;, D., Marchi, S., &amp; Aljbaae, S. 2016, Monthly Notices of the Royal Astronomical Society, 458, 1117&lt;/p&gt; &lt;p&gt;Rousseau, B., De Sanctis, M. C., Raponi, A., et al. 2020, A&amp;A, 642, A74&lt;/p&gt; &lt;p&gt;Rizos, J. L., de Le&amp;#243;n, J., Licandro, J., et al. 2019, Icarus, 328, 69&lt;/p&gt;

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