This work presents the motivation, history and current status of the Primera Luz initiative, a long-term educational project run by researchers and professionals of the Astronomy Center (CITEVA) at ...Universidad de Antofagasta (UA, Chile), primarily focused on connecting Astronomy with the people living in the Region of Antofagasta (Chile) but producing results designed to be shared with international audiences.
We explore the hypothesis that the population of Martian Trojans is the result of a balance between the production of new asteroids (“YORPlets”) through the YORP effect and their eventual escape from ...the Trojan clouds through Yarkovsky-driven orbital evolution. Our principal observables are: (5261) Eureka, its family of 8 asteroids and the family-less Trojans (101429) 1998 VF31 & (121514) 1999 UJ7. We model the population evolution as a birth-death random process and assume it is in a steady state. We then simulate the discovery of Trojans to-date and find that family members of 101429 and 121514, if they exist, are intrinsically more difficult to detect than Eureka's. Their non-discovery can be used as evidence of their non-existence only under the assumption that their brightness relative to the parent asteroid is similar to that in the Eureka family. To find out how efficiently Mars Trojans are lost from the Trojan clouds due to the Yarkovsky effect, we carry out dynamical simulations of test particles originating from these parent bodies. We find that objects originating from Eureka and 121514 begin escaping after ~1 Gyr, but that those from 101429 are already lost by that time, probably due to that asteroid's proximity to an eccentricity-type secular resonance within Mars's co-orbital region. This is the likely cause behind the absence of Trojans in the orbital vicinity of 101429. In contrast, the solitary status of 121514 points to an intrinsic inability of the asteroid to produce YORPlets during the most recent ~20% of the solar system's history, a finding potentially related to 121514’s present, low angular momentum rotational state, unless the Eureka family formed rapidly during a single fission event.
•We investigate how Eureka may sustain a Trojan asteroid family in a steady state.•We find that Yarkovsky orbit evolution causes loss of small Trojans over 108-109 yr.•Eureka may uniquely combine inefficient loss with efficient, YORP-driven production.
20573 simulations of planetary transits around spotted stars were conducted using the transit-starspot model, \texttt{PRISM}. In total 3888 different scenarios were considered using three different ...host star spectral types, M4V, M1V and K5V. The mean amplitude of the starspot anomaly was measured and compared to the photometric precision of the light curve, to determine if the starspot anomaly's characteristic "blip" was noticeable in the light curve. The simulations show that, starspot anomalies will be observable in TESS 2\,min cadence data. The smallest starspot detectable in TESS transit light curves has a radius of \(\approx1900\)\,km. The starspot detection limits for the three host stars are: \(4900\pm1700\)\,km (M4V), \(13800\pm6000\)\,km (M1V) and \(15900\pm6800\)\,km (K5V). The smallest change in flux of the starspot (\(\Delta F_\mathrm{spot} = 0.00015\pm0.00001\)) can be detected when the ratio between the planetary and stellar radii, \(k = 0.082\pm0.004\). The results confirm known dependencies between the amplitude of the starspot anomaly and the photometric parameters of the light curve. The results allowed the characterisation of the relationship between the change in flux of the starspot anomaly and the change in flux of the planetary transit for TESS transit light curves.
We explore the hypothesis that the population of Martian Trojans is the result of a balance between the production of new asteroids ("YORPlets") through the YORP effect and their eventual escape from ...the Trojan clouds through Yarkovsky-driven orbital evolution. Our principal observables are: (5261) Eureka, its family of 8 asteroids and the family-less Trojans (101429) 1998 VF31 & (121514) 1999 UJ7. We model the population evolution as a birth-death random process and assume it is in a steady state. We then simulate the discovery of Trojans to-date and find that family members of 101429 and 121514, if they exist, are intrinsically more difficult to detect than Eureka's. Their non-discovery can be used as evidence of their non-existence only under the assumption that their brightness relative to the parent asteroid is similar to that in the Eureka family. To find out how efficiently Mars Trojans are lost from the Trojan clouds due to the Yarkovsky effect, we carry out dynamical simulations of test particles originating from these parent bodies. We find that objects originating from Eureka and 121514 begin escaping after ~1 Gyr, but that those from 101429 are already lost by that time, probably due to that asteroid's proximity to an eccentricity-type secular resonance within Mars's co-orbital region. This is the likely cause behind the absence of Trojans in the orbital vicinity of 101429. In contrast, the solitary status of 121514 points to an intrinsic inability of the asteroid to produce YORPlets during the most recent ~20% of the solar system's history, a finding potentially related to 121514's present, low angular momentum rotational state, unless the Eureka family formed rapidly during a single fission event.
Astronomy provides important challenges for computer sciences, since there are many astronomical phenomena that must be studied through computational means. One of them is cataclysmic variable stars ...(CV). These phenomena must be studied through indirect observation techniques, since modern instruments are not able to directly obtain information about their structure and behavior. One of such techniques, Doppler tomography, uses a search algorithm to generate an image, called tomogram that depicts the relevant structures of a cataclysmic variable star. One important drawback of this algorithm is that it lacks any criteria to decide when to stop the search. This paper proposes an approach to automatically stop the algorithm based on the quality of the tomogram. The approach is to process each tomogram with the Sobel operator and then calculate the standard deviation (SD) of the result. The SD values of all of the tomograms generated during the search are introduced into a feed-forward neural network that indicates which tomograms have the best scientific quality. The neural network training data was created with the assessment of an expert astronomer.
