This paper supplements Kerschbaum and Hron (1994), where new JHKL'M observations of 200 Semiregular variables of types SRa and SRb were presented with additional 44 near infrared observations and 5 literature data sets. The total sample was defined in Kerschbaum & Hron (1992, Paper I) by means of a certain limit in bolometric magnitude. From the sample of 350 objects, 303 now have near infrared (NIR) photometry. In total 339 datasets are available because of some multiple observations. A detailed analysis of the whole dataset will be presented in a forthcoming paper.
We have analyzed our long-term (1995-2008) JHKLM photometry for three variable RV Tau supergiants. It follows from this analysis that: the amplitude of the JHK brightness variations is approximately the same, 0.9-1mag, for the three stars; a negative linear trend is noticeable in the variations of the mean J brightness for AC Her; and the mean J brightness of R Sct and V Vul remained constant. The observed J brightness fluctuations in the supergiants are shown to be consistent either only with the temperature pulsations (AC Her and V Vul) or with the temperature and radial pulsations (R Sct).
Multi-epoch near-infrared photometry for a sample of long period variables (SR, L, Mira). Data have been obtained at the Observatorio del Teide using the 1.5m "Carlos Sanchez Telescope" with the "CVF Photometer-Spectrophotometer". The sample has been selected based on three observing programs at the ISO satellite.
MWC 560 (V694 Mon) is one of the most enigmatic symbiotic system with a very active accretion-powered hot component. Such activity can be supported only by a luminous asymptotic giant branch star, i.e. a Mira or SR variable, with a high mass-loss rate. It is also a very unusual jet source because the jet axis lies practically parallel to the line of sight. The aims of our study are the determination of the evolutionary status of the cool component of MWC 560. Our methods involve analysis of near-IR JHKL and optical light curves. The cool component of MWC 560 pulsates with a period of ~340 days, and it is probably a red SR variable on the thermally pulsing AGB. The high mass-loss rate expected for such a star is sufficient to power the observed activity of the hot companion.
We present a subset of the results of a three-season, 124 nights, near-infrared monitoring campaign of the dark clouds Lynds 1003 and Lynds 1004 in the Cygnus OB7 star-forming region. In this paper, we focus on the field star population. Using three seasons of UKIRT J, H, and K-band observations spanning 1.5 years, we obtained high-quality photometry on 9200 stars down to J=17mag, with photometric uncertainty better than 0.04mag. After excluding known disk-bearing stars we identify 149 variables-1.6% of the sample. Of these, about 60 are strictly periodic, with periods predominantly <2days. We conclude this group is dominated by eclipsing binaries. A few stars have long period signals of between 20 and 60 days. About 25 stars have weak modulated signals, but it was not clear if these were periodic. Some of the stars in this group may be diskless young stellar objects with relatively large variability due to cool starspots. The remaining ~60 stars showed variations which appear to be purely stochastic.
We present an analysis of J, H, and Ks time-series photometry obtained with the southern 2MASS telescope over a 0.84{deg}x6{deg} region centered near the Trapezium region of the Orion Nebula cluster. These data are used to establish the near-infrared variability properties of premain-sequence stars in Orion on timescales of ~1-36days, ~2 months, and ~2 years. A total of 1235 near-infrared variable stars are identified, ~93% of which are likely associated with the Orion A molecular cloud.
Near-infrared photometric measurements for 131 Northern Galactic Cepheids are presented. The Cepheid light curves are sampled with an average of 22 measurements per star fully covering the phase of each Cepheid. The J, H, and K light curves for each Cepheid were uniformly interpolated to find the intensity mean magnitudes within each band. The results are consistent within +/-1% for 26 stars in common with previous studies. This paper is the first in a projected series of two papers which will provide additional fundamental data for Cepheids in the Galaxy, namely, NIR photometry and line-of-sight extinction. In the course of this project, 93 additional variables were fortuitously observed within the Cepheid program fields, 82 of which have previously not been identified.
