We discuss the infrared (IR) (1.25-5microns) photometry of eight planetary nebulae performed in 1999-2006. For all of the nebulae under study, we have firmly established IR brightness and color variations on time scales shorter than one year and up to 6-8 years. The greatest IR brightness variations were observed in IC 2149, IC 4997, and NGC 7662. Their J magnitudes varied within 0.2-0.25mag. In the remaining objects, the J magnitude variations did not exceed 0.15mag. All of the planetary nebulae under study exhibited IR color variations. Based on the IR photometry, we have classified the central regions of planetary nebula NGC 1514 and of the northern part of NGC 7635 seen through a 12" aperture as B(3-7) main-sequence star (NGC 1514) and O9.5 upper-main-sequence star (NGC 7635). The nebulae IC 4997 and NGC 7027 exhibited an excess emission (with respect to the emission from a hot source) at wavelength more than 2.5micron.
We present JHKLM photometric data for FG Sge, the nucleus of the planetary nebula He 1-5, obtained from 1985 to 2001, carried out on the 125cm telescope of the Sternberg Astronomical Institude's Crimean Station.
This paper presents results of JHKLM photometry data analysis of 249 southern 'IRAS-discovered' stars, which exhibit an emission feature at 11.3 microns in their low-resolution spectra (class 4n stars). The method of Epchtein et al. (1987A&AS...71...39E) is used to separate oxygen-rich and carbon-rich stars on the basis of their sole NIR and IRAS broad-band fluxes. It is shown that NIR data are necessary to calculate the total IR energy received from IRAS stars and such fundamental parameters as individual mass loss rates. An evolutionary model is developed to match the sequence of stars in color diagrams. It is suggested that the sequence of increasing optical depths might not be an evolutionary sequence, but would rather reflect the termination of a process in which the near-IR index increases very quickly at the beginning and is strongly dependent on the mass loss rate.
We present the results of 8yr of infrared photometric monitoring of a large sample of stars visible from Teide Observatory (Tenerife, Canary Islands). The final archive is made up of 10949 photometric measures through a standard InSb single-channel photometer system, principally in JHK, although some stars have measures in L'. The core of this list of stars is the standard-star list developed for the Carlos Sanchez Telescope. A total of 298 stars have been observed on at least two occasions on a system carefully linked to the zero point defined by Vega. We present high-precision photometry for these stars. The median uncertainty in magnitude for stars with a minimum of four observations and thus reliable statistics ranges from 0.0038mag in J to 0.0033mag in K. Many of these stars are faint enough to be observable with array detectors (42 are K>8) and thus to permit a linkage of the bright and faint infrared photometric systems. We also present photometry of an additional 25 stars for which the original measures are no longer available, plus photometry in L' and/or M of 36 stars from the main list.
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.
Homogeneous J, H, K, L, photometry of 42 BL Lacertae objects is presented. The observations cover a period of 3 yr with a typical time interval of 6 months.
L-band data of 30 Doradus at 3.5 micron taken with SPIREX (South Pole Infrared Explorer) is presented. The photometry was combined with 2MASS (<II/246>) JHK data at 1.25 -2.2 micron. Colour-colour and colour-magnitude diagrams are constructed and used to determine the sources with infrared excess. These are interpreted as circumstellar disks, and enable the fraction of sources with disks (the cluster disk fraction or CDF) to be determined. We find that ~42% of the sources detected at L-band in 30 Doradus have an IR-excess.
We present the results of a three-year campaign of broad-band photometry in the near-infrared J, H, K and L' bands for a sample of approximately 250 giant stars carried out at the Observatorio del Teide (Tenerife, Spain). Transformations of the Telescopio Carlos Sanchez system into/from several currently used infrared systems are extended to the redward part of the colour axis. The linearity of our photometric system in the range -3mag<K<10.5mag is inferred from the intercomparison of data of stars common to this and other photometric systems. A preliminary assessment of the photometric extinction profile of the Observatorio del Teide in JHKL' is also provided. These observations are a continuation of a programme aimed towards the progressive completion of a whole grid of T_eff_-[Fe/H]-log(g)-colour relations for population I and II stars. The analysis of optical and IR colour-colour diagrams reveals that the range F0III-K5III is well sampled for 0.5>[Fe/H]>-3. Data of comparable quality previously published have been added to the sample in order to increase the reliability of the relations to be obtained. We also provide mean IR colours for giant stars according to spectral type.
Near-Infrared JHKL photometry of the symbiotic star Hen 2-147 between 1981 and 2005, monitored from the South African Astronomical Observatory (SAAO) at Sutherland. All but one observations were made on the 0.75m telescope with the MkII Infrared Photometer; the other one (on Julian Date 2446186.4) was made with the MkIII Infrared Photometer on the 1.9m telescope. The photometry is on the SAAO system, and is good to better than +/-0.03 at JHK and better than +/-0.05 at L.
