Noemi Pinilla-Alonso

Publications (43) View all

• Source

  Available from: Noemi Pinilla-Alonso

  Article: Near-infrared spectroscopy of 1999 JU3, the target of the Hayabusa 2 mission

  N. Pinilla-Alonso, V. Lorenzi, H. Campins, J. deLeon, J. Licandro
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  ABSTRACT: Context. Primitive asteroids contain complex organic material and ices relevant to the origin of life on Earth. These types of asteroids are the target of several-sample return missions to be launched in the next years. 1999 JU3 is the target of the Japanese Aerospace Exploration Agency's Hayabusa 2 mission. Aims. 1999 JU3 has been previously identified as a C-class asteroid. Spectroscopic observations at longer wavelengths will help to constrain its composition. Methods. We obtained spectroscopy of 1999 JU3 from 0.85 to 2.2 microns, with the 3.6 m Telescopio Nazionale Galileo using the low resolution mode of the Near Infrared Camera Spectrograph. Results. We present a near-infrared spectrum of 1999 JU3 from 0.85 to 2.2microns that is consistent with previously published spectra and with its C-type classification. Conclusions. Our spectrum confirms the primitive nature of 1999 JU3 and its interest as target of the sample-return mission Hayabusa 2.
  Astronomy and Astrophysics 03/2013; 552:A79. · 4.59 Impact Factor
• Source

  Available from: Rene Duffard

  Article: Visible and near-infrared observations of asteroid 2012 DA14 during itsclosest approach of February 15th, 2013

  J. de Leon, J. L. Ortiz, N. Pinilla-Alonso, A. Cabrera-Lavers, A. Alvarez-Candal, N. Morales, R. Duffard, P. Santos-Sanz, J. Licandro, A. Perez-Romero, V. Lorenzi
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  ABSTRACT: Near-Earth asteroid 2012 DA14 made its closest approach on February 15th, 2013, when it passed at a distance of 27,700 km from the Earth's surface (inside the geosynchronous satellite ring). It was the first time an asteroid of moderate size was predicted to get that close to the Earth, becoming bright enough to permit a detailed study from ground based telescopes. Asteroid 2012 DA14 was poorly characterized before its closest approach. The main objective of this work was to obtain new and valuable data to better understand its physical properties, and to evaluate the effects of such a close approach on the object. We acquired data using several telescopes on four Spanish observatories: the 10.4m Gran Telescopio Canarias and the 3.6m Telescopio Nazionale Galileo, both in "El Roque de los Muchachos" Observatory (ORM, La Palma); the 2.2m CAHA telescope, in "Calar Alto2 Observatory (Almeria); the f/3 0.77m telescope in "La Hita" Observatory (Toledo); and the f/8 1.5m telescope in "Sierra Nevada" Observatory (Granada). We obtained visible and near-infrared colour photometry, visible spectra and time-series photometry. Visible spectra together with visible and near-infrared color photometry of 2012 DA14 show that the object can be classified as an L-type asteroid, a not very common spectral type among the asteroid population. The time-series photometry indicates a rotational period around 9 hours, and the large amplitude of the variation suggests that the object is very elongated and irregular, with an equivalent diameter around 22m. We obtain an absolute magnitude of H_R = 24.1 +- 0.2, corresponding to 24.6 +- 0.2 in V. From the absolute photometry, together with some constraints on size and shape, we compute a geometric albedo of p_V = 0.34 +- 0.20. http://arxiv.org/abs/1303.0554
  03/2013;
• Article: A compositional interpretation of trans-neptunian objects taxonomies

  Cristina Morea Dalle Ore, Luciano V. Dalle Ore, Ted L. Roush, Dale P. Cruikshank, Joshua P. Emery, Noemi Pinilla-Alonso, Giuseppe A. Marzo
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  ABSTRACT: Trans-neptunian objects (TNOs) are a population of small objects orbiting the Sun beyond Neptune. Because of their distance they are difficult to observe spectroscopically, but a large body of photometric observations is available and growing. TNOs are important tracers of the evolution of the outer Solar System and key when testing current dynamical evolution theories. Previous statistical studies of the colors of TNOs have yielded useful but limited results regarding the chemical history and evolution of these bodies. With the aim at obtaining compositional information on the small and distant TNOs we introduce a statistical cluster analysis (labelled albedo) based on colors and published albedos of TNOs. We compare it to a previous taxonomy, to illustrate the significance of including the albedo information when determining the composition of the objects. When the albedo contribution is removed from the data, the new taxonomy (now labelled classical) is in general agreement with the published ones, supporting the applicability of our approach. Making use of modeled reflectance spectra of a variety of plausible mixtures found on the surface of TNOs, we extract the average surface composition of each taxon, for both the classical and the albedo taxonomy, in a statistically consistent fashion. Differently from previous and classical, the albedo taxonomy establishes a direct link between the colors and albedos of the objects and their surface composition, allowing, for the first time, a quick assessment of the chemical history of TNOs. In fact, under closer examination the taxa show trends in composition that might be evolutionary in nature. If a simple ‘snow lines’ model is adopted, we can infer that albedo taxa relate the current objects’ locations to their original ones, prior to the migration of the outer planets. We regard the large population that characterizes the darkest classes spread at a variety of semi-major axis distances as one of the intriguing results of this work.
  Icarus 01/2013; 222(1):307-322. · 3.38 Impact Factor
• Article: Organic materials in planetary and protoplanetary systems: nature or nurture?

  C. ~M. Dalle Ore, M. Fulchignoni, D. ~P. Cruikshank, M. ~A. Barucci, R. Brunetto, H. Campins, C. Bergh de, J. ~H. Debes, E. Dotto, J. ~P. Emery, W. ~M. Grundy, A. ~P. Jones, V. Mennella, F. ~R. Orthous-Daunay, T. Owen, I. Pascucci, Y. ~J. Pendleton, N. Pinilla-Alonso, E. Quirico, G. Strazzulla
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  ABSTRACT: Aims. The objective of this work is to summarize the discussion of a workshop aimed at investigating the properties, origins, and evolution of the materials that are responsible for the red coloration of the small objects in the outer parts of the solar system. Because of limitations or inconsistencies in the observations and, until recently, the limited availability of laboratory data, there are still many questions on the subject. Our goal is to approach two of the main questions in a systematic way: – Is coloring an original signature of materials that are presolar in origin (“nature”) or stems from post-formational chemical alteration, or weathering (“nurture”)? – What is the chemical signature of the material that causes spectra to be sloped towards the red in the visible? We examine evidence available both from the laboratory and from observations sampling different parts of the solar system and cir- cumstellar regions (disks). Methods. We present a compilation of brief summaries gathered during the workshop and describe the evidence towards a primor- dial vs. evolutionary origin for the material that reddens the small objects in the outer parts of our, as well as in other, planetary systems. We proceed by first summarizing laboratory results followed by observational data collected at various distances from the Sun. Results. While laboratory experiments show clear evidence of irradiation effects, particularly from ion bombardment, the first obsta- cle often resides in the ability to unequivocally identify the organic material in the observations. The lack of extended spectral data of good quality and resolution is at the base of this problem. Furthermore, that both mechanisms, weathering and presolar, act on the icy materials in a spectroscopically indistinguishable way makes our goal of defining the impact of each mechanism challenging. Conclusions. Through a review of some of the workshop presentations and discussions, encompassing laboratory experiments as well as observational data, we infer that both “nature” and “nurture” are instrumental in the coloration of small objects in the outer parts of the solar system. While in the case of some observations it is clear that the organic reddening material originated before the solar nebula (i.e. presolar grains found in meteorites), for many other cases pointers are not as clear and indicate a concurrence of both processes.
  Astronomy and Astrophysics 09/2011; 533:A98. · 4.59 Impact Factor
• Article: New observations of asteroid (175706) 1996 FG3, primary target of the ESA Marco Polo-R mission

  J. León de, T. Mothé-Diniz, J. Licandro, N. Pinilla-Alonso, H. Campins
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  ABSTRACT: Context. Near-Earth asteroid (175706) 1996 FG3 is the primary target of the ESA Marco Polo-R mission, which was selected for the assessment study phase of ESA M3 missions. This is a primitive (C-type), binary asteroid that will allow new research to be performed. The primary is a rapidly rotating (3.6 h) small asteroid (1.4 km diameter) that is almost spherical and has a satellite of ∼400 m. Aims. We analyse new ground-based spectroscopic data of 1996 FG3 to help us characterise its surface composition and prepare for the mission. Methods. We obtained a near-infrared spectrum covering the range 0.8–2.5 μm, using the camera-spectrograph NICS at the 3.6 m telescope TNG (Telescopio Nazionale Galileo), located at “El Roque de los Muchachos” Observatory on La Palma, Spain. We com- bine our near-infrared spectrum with previously published data, and compare all the available spectra of this asteroid with the spectra of meteorites to constrain the mineralogy of the asteroid. Results. Our spectrum of FG3 differs remarkably from previously published ones. Spectral classification performed using the com- plete visible and near-infrared range yields more than one result, varying from C to Xk types. However, all the possible spectral types indicate that this asteroid is a primitive object. The comparison with meteorites behaves in the same way, providing several good matches to our new near-infrared spectrum (CM2 carbonaceous chondrite, and L6 and H4 ordinary chondrites), and only one match in the case of the previously published spectra (weakly shocked H4 ordinary chondrite, dark vein). The albedo of the asteroid (∼0.04), is typical of a primitive object, and is consistent with the reflectance value at 0.55 μm of the CM2 carbonaceous chondrite. Further observations will be essential to help us characterise more clearly the mineralogy of this asteroid.
  Astronomy and Astrophysics 01/2011; 530:L12. · 4.59 Impact Factor