TIGRE
"el-TIGRE" (el-Telescopio Internacional de Guanajuato, Robótico-Espectroscópico - previously known as HRT - Hamburg Robotic Telescope) is a private and flexible telescope which results from a partnership between Hamburg, Guanajuato, and Liège universities. It is installed in La Luz observatory, in Mexico, a 2400 meter altitude site belonging to the University of Guanajuato. Meteorological conditions on the site are favorable with more than 60% of nights with good weather (and about 80% in winter).
The telescope's primary mirror is of 1.2 m diameter, i.e., well adapted for bright stars studies: it is of Nasmyth type with a modern Alt-Az mount (like the ESO/VLT in Chile). It is equipped with an instrument called 'spectrometer' that accurately analyzes the spectrum, i.e., the distribution of light with respect to frequency. To better understand what this means, a pedagogical booklet is available (in French) with explanations, exercises, and experiences.
The specificity of the TIGRE project is to enable long sequences of observations (months to years), which is no longer possible in large observatories where only a few hours of observing time are allocated. Since the telescope saw its first light in March 2013, it has taken >50 000 spectra of > 1000 targets. They were used in about a hundred scientific publications. Among them can be found the monitoring of the activity in stars similar to the Sun (which has a 11 year activity cycle for sunspots and eruptions), the discovery or in-depth study of massive binaries, or the analysis of hot star variability. In addition, thanks to its flexibility and quick response, TIGRE could also follow several (super)novae or provide optical spectra of targets simultaneously with space-based observations in the X-ray range taken by XMM-Newton or e-ROSITA, allowing researchers to broaden their view and thereby reach a better understanding of stars!
All publications using TIGRE data can be found on the ADS. Two articles (Schmitt et al. 2014 and Gonzalez-Perez et al. 2022) can also be useful to discover the project in more details.
