16 research outputs found
Alien Registration- Snodgrass, Eva M. (Portland, Cumberland County)
https://digitalmaine.com/alien_docs/22258/thumbnail.jp
Observational and Dynamical Characterization of Main-Belt Comet P/2010 R2 (La Sagra)
We present observations of comet-like main-belt object P/2010 R2 (La Sagra)
obtained by Pan-STARRS 1 and the Faulkes Telescope-North on Haleakala in
Hawaii, the University of Hawaii 2.2 m, Gemini-North, and Keck I telescopes on
Mauna Kea, the Danish 1.54 m telescope at La Silla, and the Isaac Newton
Telescope on La Palma. An antisolar dust tail is observed from August 2010
through February 2011, while a dust trail aligned with the object's orbit plane
is also observed from December 2010 through August 2011. Assuming typical phase
darkening behavior, P/La Sagra is seen to increase in brightness by >1 mag
between August 2010 and December 2010, suggesting that dust production is
ongoing over this period. These results strongly suggest that the observed
activity is cometary in nature (i.e., driven by the sublimation of volatile
material), and that P/La Sagra is therefore the most recent main-belt comet to
be discovered. We find an approximate absolute magnitude for the nucleus of
H_R=17.9+/-0.2 mag, corresponding to a nucleus radius of ~0.7 km, assuming an
albedo of p=0.05. Using optical spectroscopy, we find no evidence of
sublimation products (i.e., gas emission), finding an upper limit CN production
rate of Q_CN<6x10^23 mol/s, from which we infer an H2O production rate of
Q_H2O<10^26 mol/s. Numerical simulations indicate that P/La Sagra is
dynamically stable for >100 Myr, suggesting that it is likely native to its
current location and that its composition is likely representative of other
objects in the same region of the main belt, though the relatively close
proximity of the 13:6 mean-motion resonance with Jupiter and the (3,-2,-1)
three-body mean-motion resonance with Jupiter and Saturn mean that dynamical
instability on larger timescales cannot be ruled out.Comment: 23 pages, 13 figures, accepted for publication in A
Exocomets from a Solar System Perspective
Exocomets are small bodies releasing gas and dust which orbit stars other
than the Sun. Their existence was first inferred from the detection of variable
absorption features in stellar spectra in the late 1980s using spectroscopy.
More recently, they have been detected through photometric transits from space,
and through far-IR/mm gas emission within debris disks. As (exo)comets are
considered to contain the most pristine material accessible in stellar systems,
they hold the potential to give us information about early stage formation and
evolution conditions of extra Solar Systems. In the Solar System, comets carry
the physical and chemical memory of the protoplanetary disk environment where
they formed, providing relevant information on processes in the primordial
solar nebula. The aim of this paper is to compare essential compositional
properties between Solar System comets and exocomets. The paper aims to
highlight commonalities and to discuss differences which may aid the
communication between the involved research communities and perhaps also avoid
misconceptions. Exocomets likely vary in their composition depending on their
formation environment like Solar System comets do, and since exocomets are not
resolved spatially, they pose a challenge when comparing them to high fidelity
observations of Solar System comets. Observations of gas around main sequence
stars, spectroscopic observations of "polluted" white dwarf atmospheres and
spectroscopic observations of transiting exocomets suggest that exocomets may
show compositional similarities with Solar System comets. The recent
interstellar visitor 2I/Borisov showed gas, dust and nuclear properties similar
to that of Solar System comets. This raises the tantalising prospect that
observations of interstellar comets may help bridge the fields of exocomet and
Solar System comets.Comment: 25 pages, 3 figures. To be published in PASP. This paper is the
product of a workshop at the Lorentz Centre in Leiden, the Netherland
Alien Registration- Snodgrass, Eva M. (Portland, Cumberland County)
https://digitalmaine.com/alien_docs/22258/thumbnail.jp
Error Type and Lexical Frequency Effects: Error Detection in Swedish Children With Language Impairment
Search for the return of activity in active asteroid 176P/LINEAR
We present the results of a search for the reactivation of active asteroid 176P/LINEAR during its 2011 perihelion passage using deep optical observations obtained before, during, and after that perihelion passage. Deep composite images of 176P constructed from data obtained between 2011 June and 2011 December show no visible signs of activity, while photometric measurements of the object during this period also show no significant brightness enhancements similar to that observed for 176P between 2005 November and 2005 December when it was previously observed to be active. An azimuthal search for dust emission likewise reveals no evidence for directed emission (i.e., a tail, as was previously observed for 176P), while a one-dimensional surface brightness profile analysis shows no indication of a spherically symmetric coma at any time in 2011. We conclude that 176P did not in fact exhibit activity in 2011, at least not on the level on which it exhibited activity in 2005, and suggest that this could be due to the devolatization or mantling of the active site responsible for its activity in 2005
Promoting health or securing the market? The right to health and intellectual property between radical contestation and accommodation
The Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) firmly enshrined a legal framework guaranteeing enforceable minimum intellectual property (IP) standards at the international level. But it also resulted in a greater inclusion of intellectual property rights (IPRs) in wider political debates between developing and industrialised countries – for instance on questions of global health and development. This paper argues that the increasing reach and efficacy of the IP regime has given rise to wider challenges to the IP system needing urgent conceptual analysis. The focus here is on IP’s increasing confrontation with the right to health, which is analysed not as an encounter of radically opposed legal systems, but as an ambivalent process in which the right to health operates as a challenge to the IP system – and, paradoxically, as an argument for its extension. To account for this ambivalence, the analysis develops a Foucauldian understanding of the right to health’s potential challenge, re-evaluating the right to health’s role as a part of a process of incremental realisation of governmental priorities, which negotiates tensions between guaranteeing the function of the economy and improving the health of populations. While this incremental process draws attention to the limitations of the right to health’s potential to challenge the IP regime, it also highlights this regime’s difficulty in accommodating a wider range of active entrepreneurial subject
The LCO Outbursting Objects Key Project: Overview and Year 1 Status
The LCO Outbursting Objects Key (LOOK) Project uses the telescopes of the Las Cumbres Observatory (LCO) Network to (1) systematically monitor a sample of previously discovered over the whole sky, to assess the evolutionary state of these distant remnants from the early solar system, and (2) use alerts from existing sky surveys to rapidly respond to and characterize detected outburst activity in all small bodies. The data gathered on outbursts helps to characterize each outburst’s evolution with time, helps to assess the frequency and magnitude distribution of outbursts in general, and contributes to the understanding of outburst processes and volatile distribution in the solar system. The LOOK Project exploits the synergy between current and future wide-field surveys such as ZTF, Pan-STARRS, and LSST, as well as rapid-response telescope networks such as LCO, and serves as an excellent test bed for what will be needed for the much larger number of objects coming from Rubin Observatory. We will describe the LOOK Project goals, the planning and target selection (including the use of NEOexchange as a Target and Observation Manager or “TOM”), and results from the first phase of observations, including the detection of activity and outbursts on the giant comet C/2014 UN271 (Bernardinelli–Bernstein) and the discovery and follow-up of 28 outbursts on 14 comets. Within these outburst discoveries, we present a high-cadence light curve of 7P/Pons–Winnecke with 10 outbursts observed over 90 days, a large outburst on 57P/duToit–Neujmin–Delporte, and evidence that comet P/2020 X1 (ATLAS) was in outburst when discovered