In this contribution, we present the main characteristics and describe the functioning of the code developed in python language to automatically build the list of objects that are nightly observed in queue mode with the 1-m SAINT-EX telescope.Fil: Petrucci, Romina Paola. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Departamento de Astrofísica Estelar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gómez Maqueo Chew, Yilen. Instituto de Astronomia; México. Universidad Nacional Autónoma de México; Méxic

Gómez Maqueo Chew, Yilen

Petrucci, Romina Paola

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BAAA, Vol. 63, 2022 Asociación Argentina de Astronomı́aR.D. Rohrmann, M.N. Gómez, C.E. Boeris & M.A. Sgró, eds. Bolet́ın de art́ıculos cient́ıficosAutomated code for the selection of targets to be observedwith the SAINT-EX telescopeR.P. Petrucci1,2 & Y. Gómez Maqueo Chew31 Observatorio Astronómico de Córdoba, UNC, Argentina2 Consejo Nacional de Investigaciones Cient́ıficas y Técnicas, Argentina3 Instituto de Astronomı́a, Universidad Nacional Autónoma de México, MéxicoContact / romina.petrucci@unc.edu.arResumen / En esta contribución, presentamos las caracteŕısticas principales y describimos el funcionamiento delcódigo desarrollado en lenguaje python para la construcción automática de la cola de observación de los objetosque serán observados durante la noche con el telescopio SAINT-EX de 1-m.Abstract / In this contribution, we present the main characteristics and describe the functioning of the codedeveloped in python language to automatically build the list of objects that are nightly observed in queue modewith the 1-m SAINT-EX telescope.Keywords / techniques: photometric — planets and satellites: detection — stars: late-type — planets andsatellites: terrestrial planets1. IntroductionSAINT-EX (Search And characterIsatioN of TransitingEXoplanets) is a project that arises as a collaborationbetween the SAINT-EX Consortium and the Universi-dad Nacional Autónoma de México (UNAM). This en-deavor has two main scientific purposes that involve theuse of high precision photometry (Sabin et al., 2018): 1)to detect and characterize terrestrial transiting planetsaround ultra-cool dwarfs (Sebastian et al., 2021) , and 2)to provide ground-based support for the ESA CHEOPSspace mission (Benz et al., 2021). To achieve these goals,between 2017 and 2019 a 1-m telescope equipped witha CCD Andor Ikon camera was installed at the Obser-vatorio Astronómico Nacional de la Sierra de San PedroMártir (OAN-SPM, México). In March 2019, the facil-ity became fully operational and, since then, it has beenperforming nightly observations only interrupted duringthe first six months of the COVID-19 pandemic. Here,it is important to mention that the scientific objectiverelated to the ultra-cool dwarfs is performed in collabo-ration with the SPECULOOS team (Delrez et al., 2018).So far, SAINT-EX has confirmed three planetarysystems (Demory et al., 2020; Wells et al., 2021;Schanche et al., 2022), initially identified as candidatesby the TESS space mission (Ricker et al., 2015). Thesuccess of this project in such a short term can beattributed, in part, to the efficiency in the observ-ing preparation, and the data acquisition and analysis,which are performed in a fully robotic and remote way.In this context, we present in this contribution themain characteristics and describe the functioning of thecode developed in python language to build the list ofobjects that are nightly observed in queue mode withthe 1-m SAINT-EX telescope.2. Code main characteristics and functioningThe purpose of this code, written in python, is to au-tomatically generate the list of targets, ordered by pri-ority, that are observed nightly with the 1-m SAINT-EX telescope. It is mainly based on the libraries forobservations planning and scheduling provided by theastropy (Astropy Collaboration et al., 2013, 2018) andastroplan (Morris et al., 2018) software, but also usesdifferent tasks created by the authors to compute thetargets’ priority. The functioning of the code is shownin Figure 1 and described in the next paragraphs.It requires as input a file containing the name, equa-torial coordinates in epoch J2000, magnitude (J or K),and spectral type of all the stars in the sample. Ba-sically, for each target, the code assesses five differentmodules and assigns a weight between 0 and 1 each.These modules are: Module 1: Number of observed hours. According toSebastian et al. (2021), the most efficient observingstrategy to increase the chances of finding a transit-ing planet is to observe each target for at least 100hours on consecutive nights. Therefore, this mod-ule assigns more weight to the stars that have beenobserved for less than 100 hours. Module 2: Declination. Given that SAINT-EX islocated in the North Hemisphere, if the star has adeclination > +20◦ it receives a greater weight thana star that has a declination ≤ +20◦. Module 3: Magnitude. In order to have high signal-to-noise images, this module assigns a greater weightto brighter stars with J ≤ 14. Module 4: Spectral type. Stars with spectral typeslater or equal to M7 receive a larger weight thanstars with spectral types earlier than M7.Poster contributionAutomated code for the SAINT-EX targets’ selectionFigure 1: Flow Chart describing the functioning of the code to select the optimum targets to be observed by the SAINT-EXtelescope in regular operations using queue robotic mode. See the text for details. Module 5: Transit window. This module was de-signed for those targets that have to be observedon a specific time interval, for example, to confirm aknown transit event. In these cases, the star receivesthe highest weight to be observed in the transit win-dow.After the evaluation of each module, the priority ofeach star is computed as the product of the weights as-signed per module. Then, a preliminary list of selectedtargets is set, where the target with the highest priorityis ranked in the first place. The final list is generatedin the next step, after the code checks different obser-vational constraints, including among others: The separation between Moon and target. Thisneeds to be larger or equal to 30◦ to avoid excessivescattered moonlight, which is difficult to correct. The amount of night time that the target is visi-ble above 28◦ over the horizon?. This point is veryimportant because, in the preliminary list, severaltargets will have the same highest priority, but thecode will only select the ones visible for the longest?This limit of 28◦ is set by the minimum altitude the tele-scope can reach safely.BAAA, 63, 2022Petrucci & Gómez Maqueo Chewperiods as “optimal”. If the target has a specified transit window. The times at which different twilights occur to prop-erly set the start and end times of each target’s ob-servations.If any of the top priority stars in the preliminarylist has a conflict with any observational constraint, itis removed and the next target in the list is considered.As result, the code builds up the final list of targets tobe observed nightly.As output, the code provides: i) a visibility plot ofthe selected optimum targets as shown in Figure 2. Col-ored solid lines indicate the airmass of the star as afunction of time and the shaded areas point out thetime interval at which each target will be observed bySAINT-EX. The gray shaded areas mark the civil, nau-tical, and astronomical twilight at dawn and dusk, ii)a series of scripts with information about the exposuretime, filter, start and end of the observations of eachtarget, also instructions to open and close the dome, toturn on and off the telescope and CCD, and to take thenumber of the required calibration images (bias, dark,and dusk and dawn flat-fields) with their correspond-ing integration times. These scripts are uploaded to thetelescope control computer with the appropriate formatto be read by the program that carries out the auto-mated observations.3. ConclusionsThis code has been successfully used to select the op-timal targets to be observed nightly, since the commis-sioning of the SAINT-EX telescope. However, there aresome aspects that still need to be improved. As an ex-ample, so far, the code computes the integration time(texp) of each star only through its magnitude. In somecases, this leads to an overestimation of texp producingsaturated or near-saturated images. In the future, itwould be desirable that the code calls to a more sophisti-cated tool, such as the Exposure Time Calculator (ETC)used by the SPECULOOS team (Delrez et al., 2018)that includes information about the CCD, atmosphericconditions, etc to calculate realistic texp. Another pointof improvement would be to include the number of hoursthat each ultra-cool dwarf is observed with the SPECU-LOOS telescopes. At the moment, module 1 only con-siders the hours monitored by SAINT-EX. Additionally,so far, this code is optimized for the SAINT-EX obser-vation queue, only. In the near future, we expect toimplement an option that will allow the user to enterthe coordinates (latitude, longitude, and height aboveFigure 2: Visibility plot of the optimum targets selected bythe code. Blue and orange solid lines indicate the airmassas a function of time of targets 1 and 2, respectively. Darkgreen and violet shaded areas point out the time intervalat which each of these targets will be observed by SAINT-EX. Different gray shaded areas mark the civil, nautical, andastronomical twilight at dawn and dusk.sea level) of any observatory to generate its own ob-servation queue. This new version of the code will beavailable for the community through GitHub.Acknowledgements: This work has been supported by UNAM-PAPIIT IG-101321. R.P acknowledges DGAPA (Dirección Gen-eral de Asuntos del Personal Académico) for her postdoctoral fel-lowship granted between 2018 and 2020. We thank the referee forhis/her comments.ReferencesAstropy Collaboration, et al., 2013, A&A, 558, A33Astropy Collaboration, et al., 2018, AJ, 156, 123Benz W., et al., 2021, Experimental Astronomy, 51, 109Delrez L., et al., 2018, H.K. Marshall, J. Spyromilio (Eds.),Ground-based and Airborne Telescopes VII, Society ofPhoto-Optical Instrumentation Engineers (SPIE) Confer-ence Series, vol. 10700, 107001IDemory B.O., et al., 2020, A&A, 642, A49Morris B.M., et al., 2018, AJ, 155, 128Ricker G.R., et al., 2015, J. Astron. Telesc. Instrum. Syst.,1, 014003Sabin L., et al., 2018, 20th Cambridge Workshop on CoolStars, Stellar Systems and the Sun, 59, Cambridge Work-shop on Cool Stars, Stellar Systems, and the SunSchanche N., et al., 2022, A&A, 657, A45Sebastian D., et al., 2021, A&A, 645, A100Wells R.D., et al., 2021, A&A, 653, A97BAAA, 63, 2022

Automated code for the selection of targets to be observed with the SAINT-EX telescope

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Automated code for the selection of targets to be observed with the SAINT-EX telescope

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