NIRPS: the Near-InfraRed Planet Searcher joining HARPS on the 3.6-m

<p>The Near-InfraRed Planet Searcher (NIRPS) is designed to be an ultra-stable infrared spectrograph to be installed on ESO’s 3.6 m Telescope in La Silla, Chile. NIRPS is an adaptive optics (AO) fiber-fed spectrograph operating from 0.98 to 1.8 μm and will be operated simultaneously with the optical high-resolution spectrograph HARPS. NIRPS can operate in two modes fed by two different fiber links permanently mounted at the Cassegrain focus that use either 0.4 arcsecond-fibers for the High Accuracy Mode (HAM) or 0.9 arcsecond-fibers for the High Efficiency Mode (HEM). The wavelength range of NIRPS is optimal for low-mass M dwarfs and the simultaneous NIRPS and HARPS observations will improve stellar activity filtering methods given their different wavelength coverages. The NIRPS front-end and AO system were already tested on-sky at La Silla. The spectrograph and back-end is being shipped to La Silla and installed in Summer/Fall 2021. Already we have adapted the state-of-the-art ESPRESSO data reduction pipeline for NIRPS, obtained accurate wavelength solutions with a Uranium Neon lamp, and obtained drift stability results below 50 cm/s with a Fabry–Pérot etalon. We discuss the current and expected instrument performance and the expected results of NIRPS.</p>

Evaluation of light-traps with coloured glue-boards for sampling and control of the house fly Musca domestica L.

Results regarding the combination of light-traps and coloured glue-boards for the trap and control of the house fly, Musca domestica L. (Diptera: Muscidae), are reported. Monitoring was performed using as basic structure PRO 80S UV fluorescent fly traps in a confinement swine farm in the south of Italy. During the trials, neon traps with a combination of glue-boards (yellow vs black and yellow vs white) and neon vs LED traps with yellow glue-boards were evaluated. Results indicated that yellow and black glue-boards were equally attractive to flies, with no significant differences. Light-traps captured significantly more flies when a white glue-board was used rather than a yellow panel. The neon lamp attracted significantly more flies than the LED lamp. According to our results, light-traps with white panels have potential to be employed in Integrated Pest Management (IPM) programs for monitoring and controlling house flies in livestock farms and in food processing, reducing risks in dissemination of pathogens which have the potential to affect humans or animals.

Using modulation acousto-optic spectrometry to locate spectral features in overlapping spectra

The spectrometer is not able to accurately determine the spectral position of the smaller maximum if it is located against the background of a powerful broad peak. The solution of the problem is known it is enough to differentiate the existing dependence, and the position of the smaller peak is determined with sufficient accuracy. Based on a quasi-collinear acousto-optic (AO) cell, a prototype spectrometer was created, which makes it possible to record both the spectrum of the optical signal and its derivative in real time. In the course of the work, a more detailed research of the work of the created model was carried out: the value of the phase shift was changed programmatically from zero to 360°, and the spatial modulation period - from zero to the length of the AO cell L. A neon lamp and all the data presented were used as a radiation source, were obtained for the same emission line. The maximum signal for the derivative corresponds to the phase values of 90° and 270°. In another series of experiments, the work of the model was investigated with a change in the modulation period (the phase shift is fixed, ψ=π/2). The maximum signal for the derivative corresponds to the values of the modulation period duration equal to L/2, half the length of the acousto-optic cell. The graphs of the results of "physical" and "mathematical" differentiation do not coincide. We assume that the differences are related to the shape of the instrumental function of the acousto-optical spectrometer. However, at the tops of the spectral peaks, in the regions of intersection of derivatives with a zero line, the results coincide, which makes it possible to use acousto-optic differentiation to reveal the "fine structure" of optical spectra, and in real time. Thus, as a result of the work carried out: a method was proposed for the precise determination of the position of spectral maxima in complex overlapping spectra in real time; an instrumental implementation of the proposed method was created, and it was shown that for the visible range (532 nm) the accuracy of determining the spectral position of the maxima is 0.2 nm.

ONE-DIMENSIONAL DYNAMICS OF THE VAN DER POL CIRCUIT

The van der Pol circuit with neon glow lamp operates as a relaxation oscillator driven by a sinusoidal voltage source. Its dynamics is described by the function which maps an arc of circle into itself, preserves orientation on this arc, and has at most one jump-discontinuity point on the circle. Properties of this mapping are discussed with emphasis on rotation numbers, types of periodic orbits, saddle-node and border-collision bifurcations. The so-called period-adding phenomenon is explained. Some remarks are given about dynamics, where the mapping does not preserve the orientation because of too long neon lamp lighting.