Related papers: The extreme Type I planetary nebula M2-52
We present medium resolution (1000) K-band spectra of 12 post-AGB candidates and related stars. For several objects in our sample, these spectra were obtained for the first time. The Br$\gamma$ line in emission is detected in seven objects…
The Isaac Newton Telescope Photometric H-alpha Survey (IPHAS) is currently mapping the Northern Galactic plane reaching to r'=20 mag with typically 1" resolution. Hundreds of Planetary Nebulae (PNe), both point-like and resolved, are…
Recently gathered observational data on a sample of Type Ia Supernovae (SNe Ia) reveal a wide distribution of expansion velocities of the Fe cores, measured from the width of the nebular lines. Moreover, the velocity appears to correlate…
Deep, narrow-band \Ha\ and 6584 \AA\ [\Nii ] CCD images of the peculiar, infrared excess B[e] star MWC~922 reveal a collimated, bipolar jet orthogonal to the previously detected extended nebula. The jet consists of a pair of $\sim$0.15 pc…
We report deep long-slit emission-line spectra, the line flux ratios, and Doppler profile shapes of various bright optical lines. The low-ionization lines (primarily [N I], [O I], [S II], and [N II]) originate in shocked knots, as reported…
NGC 6302 is a spectacular bipolar planetary nebula (PN) whose spectrum exhibits fast outflows and highly ionized emission lines, indicating the presence of a very hot central star (~220,000 K). Its infrared spectrum reveals a mixed oxygen…
We present medium-dispersion spectra and narrowband images of six northern compact planetary nebulae (PNe): BoBn 1, DdDm 1, IC 5117, M 1-5, M 1-71, and NGC 6833. From broad-slit spectra, total absolute fluxes and equivalent widths were…
We present low and high resolution long-slit spectra of three bipolar planetary nebulae (PNe) with bright central cores: A79, He2-428 and M1-91. He2-428 and M1-91 have high density (from 10^3.3 to 10^6.5 cm^-3) unresolved nebular cores that…
The central parsec of the Milky Way is a very special region of our Galaxy; it contains the supermassive black hole associated with Sgr A* as well as a significant number of early-type stars and a complex structure of streamers of neutral…
High resolution spectra of the hot central star of the planetary nebula (CSPN) M27, acquired with the Far Ultraviolet Spectroscopic Explorer (\FUSE), have revealed an unusually rich set of narrow molecular hydrogen absorption features. This…
We present photoelectric and spectral observations of a hot candidate proto-planetary nebula - early B-type supergiant with emission lines in spectrum - IRAS 19336-0400. The light and color curves display fast irregular brightness…
Spectroscopic observations obtained with the VLT of one planetary nebula (PN) in Sextans A and of five PNe in Sextans B and of several HII regions (HII) in these two dwarf irregular galaxies are presented. The extended spectral coverage,…
We present a comprehensive photometric and spectroscopic study of the Type IIP SN 2018is. The $V$-band luminosity and the expansion velocity at 50 days post-explosion are $-$15.1$\pm$0.2 mag (corrected for A$_V$=1.34 mag) and 1400 km…
This paper discusses the location of a sample of planetary nebulae on the HR diagram. We determine the internal velocity fields of 14 planetary nebulae from high-resolution echelle spectroscopy, with the help of photoionization models. The…
We study the characteristics of planetary nebulae (PNe), MaC 2-1 and Sp 4-1. We use our optical spectra taken at 2 m Himalayan Chandra Telescope, Spitzer mid-infrared (mid-IR) spectra, HST images, and IR photometric data. These PNe have not…
Aims. Numerous planetary nebulae show complicated inner structures not obviously explained. For one such object we undertake a detailed 3D photoionization and kinematical model analysis for a better understanding of the underlying shaping…
We have obtained deep narrowband images in the near-infrared H2 (2.122 microns) emission line for a sample of 15 faint Isaac Newton Telescope Photometric Halpha Survey (IPHAS) bipolar planetary nebulae (PNe) to search for molecular…
We performed multiwavelength observations of the young planetary nebula (PN) M1-11 and obtained its elemental abundances, dust mass, and the evolutionary status of the central star. The AKARI/IRC, VLT/VISIR, and Spitzer/IRS spectra show…
The shaping of planetary nebulae on their evolution from asymptotic giant branch circumstellar envelopes to their final, most often axisymmetrical, form is still a process with many unknown details. The key to understanding the whole…
We present [N II] and H-alpha images and high resolution long-slit spectra of the planetary nebula IC 4846, which reveal, for the first time, its complex structure and the existence of collimated outflows. The object consists of a…