60 citations · 137 across the 5 of their papers we have counts for
5 papers
The Ca II infrared triplet's performance as an activity indicator compared to Ca II H and K
J. Martin, B. Fuhrmeister, M. Mittag +4
Aims. A large number of Calcium Infrared Triplet (IRT) spectra are expected from the GAIA- and CARMENES missions. Conversion of these spectra into known activity indicators will al…
Carrington cycle 24: The solar chromospheric emission in a historical and stellar perspective
K. -P. Schroder, M. Mittag, J. H. M. M. Schmitt +3
We present the solar S-index record of cycle 24, obtained by the TIGRE robotic telescope facility and its high-resolution spectrograph HEROS (R20,000), which measures the…
Study of the variability of Nova V5668 Sgr, based on high resolution spectroscopic monitoring
D. Jack, J. de J. Robles Pérez, I. De Gennaro Aquino +9
We present results of our dense spectroscopic monitoring of Nova V5668 Sgr. Starting on March 19 in 2015, only a few days after discovery, we have obtained a series of spectra with…
Chromospheric activity and evolutionary age of the Sun and four solar twins
M. Mittag, K. -P. Schröder, A. Hempelmann +2
The activity levels of the solar-twin candidates HD 101364 and HD 197027 are measured and compared with the Sun, the known solar twin 18 Sco, and the solar-like star 51 Peg. Furthe…
Time series of high resolution spectra of SN 2014J observed with the TIGRE telescope
D. Jack, M. Mittag, K. -P. Schroder +6
We present a time series of high resolution spectra of the Type Ia supernova 2014J, which exploded in the nearby galaxy M82. The spectra were obtained with the HEROS echelle spectr…