60 citations · 216 across the 10 of their papers we have counts for
10 papers
Six decades of TIGRE and Mount Wilson chromospheric monitoring in the H and K lines: The quest for an understanding of solar-type activity
J. H. M. M. Schmitt, K. -P. Schröder, M. Mittag +3
The combined time series of the consistently calibrated chromospheric activity indicator, the S-index -- derived from Mount Wilson and TIGRE data -- now spans more than five decade…
Magnetic activity of the solar-like star HD 140538
M. Mittag, J. H. M. M. Schmitt, T. S. Metcalfe +2
The periods of rotation and activity cycles are among the most important properties of the magnetic dynamo thought to be operating in late-type, main-sequence stars. In this paper,…
Intriguing X-ray and optical variations of the gamma Cas analog HD45314
G. Rauw, Y. Nazé, M. A. Smith +11
A growing number of Be and Oe stars, named the gamma Cas stars, are known for their unusually hard and intense X-ray emission. This emission could either trace accretion by a compa…
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…