Enos Picazzio

Spectroscopic observations of the comet 29P/Schwassmann-Wachmann 1 at the SOAR telescope

Abstract Spectroscopic observations of comet 29P/Schwassmann-Wachmann 1 were carried out at the SOAR 4.1-meter telescope (Chile) on August 12, 2016, when its heliocentric distance was 5.9 au. The spectra revealed CO+ and N 2 + emissions in the cometary coma. The [ N 2 + ]/[CO+] ratio within the projected slit seems to be 0.01. The mean value of the normalized spectral gradient is 12.69 ± 0.06 for spectral range 3448–5260 A.

Near infrared photometry of comet C/2005 E2 (McNaught)

We present results of JHK photometry for comet C/2005 E2 (McNaught). Observations were made with the OSIRIS imager at the SOAR telescope, on Sept. 26-27, 2005. The dependence of the main parameters on the angular distance from the cometary photometric nucleus is discussed. We considered concentric rings around the photometric nucleus of the comet, with the radius determined by the aperture. Integrated flux in the ring, surface brightness, J-H and H-K color indices, and mean flux decay were obtained for each ring. A phometric radial profile was also obtained by tracing average values of the ace brightness for increasing values of radii in isophotes which allowed us to compute the azimuthally averaged surface brightness of the coma. The images centered on the photometric nucleus show three jets from active areas on the nucleus.

Spectroscopic Studies of Comets 9P/Tempel 1, 37P/Forbes and C/2004 Q2 (Machholz)

The results of the analysis of the spectra of comets 9P/Tempel 1, 37P/Forbes and C/2004 Q2 (Machholz) observed in 2004-2005 at Observatorio do Pico dos Dias (Brazil), and at Mount Pastukhov (SAO, Russia) are presented.

Optical Spectroscopy and Near-Infrared Observations of Comet C/2000 WM1 (LINEAR) in December 2001 from Chile and Brazil

We report on the preliminary analysis of the high-resolution spectrum of Comet C/2000 WM1 (LINEAR), obtained on Dec. 1, 2001 with the Fiber fed Extended Range Optical Spectrograph (FEROS) installed on the 1.52-m telescope of ESO (Chile). Many emission lines of the molecules C2, C3, CN, CH, CH+, NH2, CO, CO+, H2O+ and, presumably, C2 − were identified in the spectral range 400–900 nm.