Coloquio IRyA esta semana/This week's colloquium at IRyA
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Sundar Srinivasan
Jul 27, 2026, 10:06:59 AMJul 27
to
Hola (English version below),
Este
jueves 30 de julio a las 12:00, Aina Palau del IRyA impartirá la plática:
"Observations of nascent brown dwarfs: paving the way to constrain theories"
Resumen:
Brown dwarfs and planetary-mass objects freely wandering in molecular clouds were discovered more than 20 years ago, but recently the number of these objects was found to be higher than previously thought. Because of this, their origin is at the heart of current debates, being the "star-like formation" or the "planet formation + subsequent ejection" the most promising scenarios. The recent observational efforts to search, identify and characterize brown dwarfs that are still embedded in their molecular clouds will be presented. A new correlation between the internal luminosity of an object and its accreted mass will be shown, essential to design future strategies to search for these elusive objects. From this review study, two main results favor the "star-like" scenario: 1) the updated correlations between protostellar properties seem to extend down to the substellar regime; and 2) a particular underproduction of low-mass proto-brown dwarfs in Ophiuchus compared to Lupus and Taurus suggests that heating of the Ophiuchus cloud by the nearby OB stars could be suppressing the formation of these objects. However, a very recent work conducted at IRyA reveals that a proto-brown dwarf candidate in Ophiuchus seems to have been ejected from a multiple system, strongly indicating that the "planet-like" scenario could be more important than previously thought.
Les pedimos que por favor:
1. Intenten conectarse ~10 minutos antes del mediodía, en caso de que haya algún problema.
2. Apaguen sus micrófonos y cámaras durante la presentación. Si estarán en el auditorio, apaguen sus celulares.
3. Reserven sus preguntas hasta el final de la presentación. Usen el botón "Raise Hand" en Zoom para hacer una pregunta, y el moderador tomará nota.
4. Mantengan abierta la ventana de chat de Zoom durante la sesión para que puedan recibir mensajes de los organizadores.
1. Intenten conectarse ~10 minutos antes del mediodía, en caso de que haya algún problema.
2. Apaguen sus micrófonos y cámaras durante la presentación. Si estarán en el auditorio, apaguen sus celulares.
3. Reserven sus preguntas hasta el final de la presentación. Usen el botón "Raise Hand" en Zoom para hacer una pregunta, y el moderador tomará nota.
4. Mantengan abierta la ventana de chat de Zoom durante la sesión para que puedan recibir mensajes de los organizadores.
El
café y las galletas estarán disponibles 15 min antes del coloquio.
Traiga sus propias tazas y no traiga bebidas ni alimentos al auditorio.
Las diapositivas de la charla, así como el video, estarán disponibles en la página web del coloquio IRyA. Los videos también se pueden encontrar en nuestro canal de YouTube.
Saludos.
************************************************************************
Saludos.
************************************************************************
Hi everyone,
On
Thursday, the 30th of July at 12:00, IRyA's own Aina Palau will present the following talk:
"Observations of nascent brown dwarfs: paving the way to constrain theories"
Abstract:
Brown dwarfs and planetary-mass objects freely wandering in molecular clouds were discovered more than 20 years ago, but recently the number of these objects was found to be higher than previously thought. Because of this, their origin is at the heart of current debates, being the "star-like formation" or the "planet formation + subsequent ejection" the most promising scenarios. The recent observational efforts to search, identify and characterize brown dwarfs that are still embedded in their molecular clouds will be presented. A new correlation between the internal luminosity of an object and its accreted mass will be shown, essential to design future strategies to search for these elusive objects. From this review study, two main results favor the "star-like" scenario: 1) the updated correlations between protostellar properties seem to extend down to the substellar regime; and 2) a particular underproduction of low-mass proto-brown dwarfs in Ophiuchus compared to Lupus and Taurus suggests that heating of the Ophiuchus cloud by the nearby OB stars could be suppressing the formation of these objects. However, a very recent work conducted at IRyA reveals that a proto-brown dwarf candidate in Ophiuchus seems to have been ejected from a multiple system, strongly indicating that the "planet-like" scenario could be more important than previously thought.
Zoom link (Meeting ID: 890 9042 2717 Passcode: c0l0#qU1o)
We request that you please:
1. Attempt to connect ~10 min before noon, in case there are any issues.
2. Turn off your mics and cameras during the presentation. If you'll be in the auditorium, please turn off your cellphones.
3. Reserve your questions till the end of the presentation. Use the "Raise Hand" button in Zoom to ask a question, and the moderator(s) will make a note.
4. Have your Zoom chat window open during the session so you are able to receive messages from the moderator(s).
1. Attempt to connect ~10 min before noon, in case there are any issues.
2. Turn off your mics and cameras during the presentation. If you'll be in the auditorium, please turn off your cellphones.
3. Reserve your questions till the end of the presentation. Use the "Raise Hand" button in Zoom to ask a question, and the moderator(s) will make a note.
4. Have your Zoom chat window open during the session so you are able to receive messages from the moderator(s).
Coffee and cookies will be
available 15 min prior to the colloquium. Please bring your own
mugs, and please do not bring beverages or food into the auditorium.
Cheers,
Ramandeep y Sundar
Sundar Srinivasan
Aug 3, 2026, 10:01:38 AMAug 3
to
Hola (English version below),
Este
jueves 6 de agosto a las 12:00, Dennis Jack de la Universidad de Guanajuato impartirá la plática:
"PHOENIX: Self-Consistent Modeling of Stellar Atmospheres and Chromospheres"
Resumen:
Astronomy is unique among the sciences because it does not allow us to study our objects of interest directly in situ. Instead, we must rely on information that reaches us primarily through electromagnetic radiation. Today, a comparison of observations with theoretical spectra is an excellent way to test and verify our physical understanding and models. Achieving this requires not only solving the radiative transfer problem but also accurately modeling the complex physics of the different types of stellar atmospheres.
In this talk, I will present the general-purpose state-of-the-art stellar model atmosphere code PHOENIX. It models spherically symmetric atmospheres and includes hydrostatic stratification, gas chemistry, non-LTE, and an extensive treatment of atomic, molecular, and dust opacities. The code also includes specific physics for a wide range of stars and stellar-like objects. I will present several applications of PHOENIX, including the modeling of supernova light curves.
Finally, I will discuss the recent development of self-consistent modeling of stellar chromospheres using the time-dependent module of PHOENIX. This approach enables us to model the temperature inversion within the atmosphere as well as observational features of stellar activity, including Ca II H & K emission, radio emission, and the Wilson-Bappu effect.
In this talk, I will present the general-purpose state-of-the-art stellar model atmosphere code PHOENIX. It models spherically symmetric atmospheres and includes hydrostatic stratification, gas chemistry, non-LTE, and an extensive treatment of atomic, molecular, and dust opacities. The code also includes specific physics for a wide range of stars and stellar-like objects. I will present several applications of PHOENIX, including the modeling of supernova light curves.
Finally, I will discuss the recent development of self-consistent modeling of stellar chromospheres using the time-dependent module of PHOENIX. This approach enables us to model the temperature inversion within the atmosphere as well as observational features of stellar activity, including Ca II H & K emission, radio emission, and the Wilson-Bappu effect.
Les pedimos que por favor:
1. Intenten conectarse ~10 minutos antes del mediodía, en caso de que haya algún problema.
2. Apaguen sus micrófonos y cámaras durante la presentación. Si estarán en el auditorio, apaguen sus celulares.
3. Reserven sus preguntas hasta el final de la presentación. Usen el botón "Raise Hand" en Zoom para hacer una pregunta, y el moderador tomará nota.
4. Mantengan abierta la ventana de chat de Zoom durante la sesión para que puedan recibir mensajes de los organizadores.
1. Intenten conectarse ~10 minutos antes del mediodía, en caso de que haya algún problema.
2. Apaguen sus micrófonos y cámaras durante la presentación. Si estarán en el auditorio, apaguen sus celulares.
3. Reserven sus preguntas hasta el final de la presentación. Usen el botón "Raise Hand" en Zoom para hacer una pregunta, y el moderador tomará nota.
4. Mantengan abierta la ventana de chat de Zoom durante la sesión para que puedan recibir mensajes de los organizadores.
El
café y las galletas estarán disponibles 15 min antes del coloquio.
Traiga sus propias tazas y no traiga bebidas ni alimentos al auditorio.
Las diapositivas de la charla, así como el video, estarán disponibles en la página web del coloquio IRyA. Los videos también se pueden encontrar en nuestro canal de YouTube.
Saludos.
************************************************************************
Saludos.
************************************************************************
Hi everyone,
On
Thursday, the 6th of August at 12:00, Dennis Jack of the University of Guanajuato will present the following talk:
"PHOENIX: Self-Consistent Modeling of Stellar Atmospheres and Chromospheres"
Abstract:
Astronomy is unique among the sciences because it does not allow us to study our objects of interest directly in situ. Instead, we must rely on information that reaches us primarily through electromagnetic radiation. Today, a comparison of observations with theoretical spectra is an excellent way to test and verify our physical understanding and models. Achieving this requires not only solving the radiative transfer problem but also accurately modeling the complex physics of the different types of stellar atmospheres.
In this talk, I will present the general-purpose state-of-the-art stellar model atmosphere code PHOENIX. It models spherically symmetric atmospheres and includes hydrostatic stratification, gas chemistry, non-LTE, and an extensive treatment of atomic, molecular, and dust opacities. The code also includes specific physics for a wide range of stars and stellar-like objects. I will present several applications of PHOENIX, including the modeling of supernova light curves.
Finally, I will discuss the recent development of self-consistent modeling of stellar chromospheres using the time-dependent module of PHOENIX. This approach enables us to model the temperature inversion within the atmosphere as well as observational features of stellar activity, including Ca II H & K emission, radio emission, and the Wilson-Bappu effect.
In this talk, I will present the general-purpose state-of-the-art stellar model atmosphere code PHOENIX. It models spherically symmetric atmospheres and includes hydrostatic stratification, gas chemistry, non-LTE, and an extensive treatment of atomic, molecular, and dust opacities. The code also includes specific physics for a wide range of stars and stellar-like objects. I will present several applications of PHOENIX, including the modeling of supernova light curves.
Finally, I will discuss the recent development of self-consistent modeling of stellar chromospheres using the time-dependent module of PHOENIX. This approach enables us to model the temperature inversion within the atmosphere as well as observational features of stellar activity, including Ca II H & K emission, radio emission, and the Wilson-Bappu effect.
Zoom link (Meeting ID: 890 9042 2717 Passcode: c0l0#qU1o)
We request that you please:
1. Attempt to connect ~10 min before noon, in case there are any issues.
2. Turn off your mics and cameras during the presentation. If you'll be in the auditorium, please turn off your cellphones.
3. Reserve your questions till the end of the presentation. Use the "Raise Hand" button in Zoom to ask a question, and the moderator(s) will make a note.
4. Have your Zoom chat window open during the session so you are able to receive messages from the moderator(s).
1. Attempt to connect ~10 min before noon, in case there are any issues.
2. Turn off your mics and cameras during the presentation. If you'll be in the auditorium, please turn off your cellphones.
3. Reserve your questions till the end of the presentation. Use the "Raise Hand" button in Zoom to ask a question, and the moderator(s) will make a note.
4. Have your Zoom chat window open during the session so you are able to receive messages from the moderator(s).
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