scholarly journals The past, present and future of Galactic planetary nebula surveys

2011 ◽  
Vol 7 (S283) ◽  
pp. 9-16 ◽  
Author(s):  
Quentin A. Parker ◽  
David J. Frew ◽  
Agnes Acker ◽  
Brent Miszalski

AbstractOver the last decade Galactic planetary nebula discoveries have entered a golden age due to the emergence of high sensitivity, high resolution narrow-band surveys of the Galactic plane. These have been coupled with access to complimentary, deep, multi-wavelength surveys across near-IR, mid-IR and radio regimes in particular from both ground-based and space-based telescopes. These have provided powerful diagnostic and discovery capabilities. In this review these advances are put in the context of what has gone before, what we are uncovering now and through the window of opportunity that awaits in the future. The astrophysical potential of this brief but key phase of late stage stellar evolution is finally being realised.

Author(s):  
T M Lawlor

Abstract We present stellar evolution calculations from the Asymptotic Giant Branch (AGB) to the Planetary Nebula (PN) phase for models of initial mass 1.2 M⊙ and 2.0 M⊙ that experience a Late Thermal Pulse (LTP), a helium shell flash that occurs following the AGB and causes a rapid looping evolution between the AGB and PN phase. We use these models to make comparisons to the central star of the Stingray Nebula, V839 Ara (SAO 244567). The central star has been observed to be rapidly evolving (heating) over the last 50 to 60 years and rapidly dimming over the past 20–30 years. It has been reported to belong to the youngest known planetary nebula, now rapidly fading in brightness. In this paper we show that the observed timescales, sudden dimming, and increasing Log(g), can all be explained by LTP models of a specific variety. We provide a possible explanation for the nebular ionization, the 1980’s sudden mass loss episode, the sudden decline in mass loss, and the nebular recombination and fading.


2016 ◽  
Vol 12 (S323) ◽  
pp. 11-19
Author(s):  
David J. Frew

AbstractDetermining the demographics of the Galactic planetary nebula (PN) population is an important goal to further our understanding of this intriguing phase of stellar evolution. The Galactic population has more than doubled in number over the last 15 years, particularly from narrowband Hα surveys along the plane. In this review I will summarise these results, with emphasis on the time interval since the last IAU Symposium. These primarily optical surveys are not without their limitations and new surveys for PNe in the infrared similarly face a number of challenges. I will discuss the need for multi-wavelength approaches to discovery and analysis. The desire to have accurate volume-limited samples of Galactic PNe at our disposal is emphasised, which will be impacted with new data from the Gaia satellite mission. We need robust surveys of PNe and their central stars, especially volume-limited surveys, in order to clarify and quantify their evolutionary pathways.


2011 ◽  
Vol 7 (S283) ◽  
pp. 440-441
Author(s):  
Luis F. Miranda ◽  
Mónica Blanco ◽  
Martín A. Guerrero ◽  
Angels Riera

AbstractWe present narrow-band optical and near-IR images, and high-resolution long-slit spectra of the planetary nebula Hu 1-2 that allow us to make a detailed description of its unusual morphology and internal kinematics. The data also reveal that the ansae of Hu 1-2 probably represent bow-shocks associated to high velocity outflows that are irradiated from the central star.


Author(s):  
J B Rodríguez-González ◽  
L Sabin ◽  
J A Toalá ◽  
S Zavala ◽  
G Ramos-Larios ◽  
...  

Abstract We present the first detailed study of the bipolar planetary nebula (PN) IPHASX J191104.8+060845 (PN G 040.6−01.5) discovered as part of the Isaac Newton Telescope Photometric Hα Survey of the Northern Galactic plane (IPHAS). We present Nordic Optical Telescope (NOT) narrow-band images to unveil its true morphology. This PN consists of a main cavity with two newly uncovered extended low-surface brightness lobes located towards the NW and SE directions. Using near-IR WISE images we unveiled the presence of a barrel like structure, which surrounds the main cavity, which would explain the dark lane towards the equatorial regions. We also use Gran Telescopio de Canarias (GTC) spectra to study the physical properties of this PN. We emphasise the potential of old PNe detected in IPHAS to study the final stages of the evolution of the circumstellar medium around solar-like stars.


1989 ◽  
Vol 131 ◽  
pp. 391-400 ◽  
Author(s):  
Alvio Renzini

Over the past decade a comprehensive, semiquantitative theoretical scenario for the final evolutionary stages of low and intermediate mass stars has been progressively elaborated and refined. It concerns the envelope ejection terminating the Asymptotic Giant Branch (AGB) phase, the AGB to Planetary Nebula (PN) transition, the fading and possible rejuvenation of PN nuclei, the formation processes of hydrogen-deficient stars, and the final production of white dwarfs (WD) of the DA and non-DA varieties (Renzini 1979, 1981a, 1981b, 1982, 1983, Iben & Renzini 1983, Iben et al. 1983, Iben 1984, 1985, 1987, Iben & Tutukov 1984, Iben & MacDonald 1985, 1986). In developing this scenario several important results of stellar evolution and hydrodynamical calculations have been incorporated, including in particular those of Paczynski (1971), Wood (1974), Härm & Schwarzschild (1975), Schönberner (1979, 1983), and Tuchman, Sack & Barkat (1979).


2003 ◽  
Vol 209 ◽  
pp. 122-122
Author(s):  
Toshiya Ueta ◽  
David Fong ◽  
Margaret Meixner

We present high-sensitivity near-IR images of a carbon-rich proto-planetary nebula, AFGL 618, obtained with the Infrared Camera and Spectrograph (IRCS) mounted on the 8.2m Subaru Telescope. The deep near-IR images have revealed “bullets” and “horns” extending farther out from the edges of the previously known bipolar nebulosities that consist of dust-scattered star light component and shock-excited line emission component. That these bullets and horns represent the positions from which [Fe II] IR lines arise is strongly suggested from the spatial coincidence between these near-IR microstructures and the optical collimated outflow structure observed by the recent HST/WFPC2 imaging, together with the previous detection of shock-excited, forbidden IR lines of atomic species at those locations. At these positions of the near-IR mincrostructures, we have also discovered CO clumps moving at > 200 km s-1 from our re-analysis of the existing 12CO J = 1 – 0 data obtained with the Berkeley-Illinois-Maryland Association (BIMA) interferometer array. These findings indicate that fast-moving CO clumps seem to be impinging upon the surrounding ambient circumstellar shell, thereby causing shocked emission regions which manifest themselves as the near-IR microstructures at the shock interface. To deepen our understanding of the connection between the near-IR microstructures and the CO outflow structure, we are currently conducting higher resolution observation in CO lines with the BIMA array.


1971 ◽  
Vol 42 ◽  
pp. 77-78
Author(s):  
C. R. O'Dell

Stellar evolution is characterized by fast and slow phases. Usually the periods of rapid change are difficult to follow observationally; but, this does not seem to be the case when passing through the planetary nebula stage. Because of their high intrinsic luminosities and easy identification, it is possible to identify and study these objects and their central stars rather completely. It is quite relevant to discuss these objects at a symposium on white dwarfs since the central stars may be in the immediate progenitor stage before white dwarfs. The actual picture of the evolution of the nuclei has changed rather little in the past few years and is the subject of an earlier review article (O'Dell, 1968) to which the reader is referred.


1977 ◽  
Vol 3 (2) ◽  
pp. 137-140 ◽  
Author(s):  
A. R. Hyland ◽  
M. P. Schwarz

Over the past ten years, there has been considerable interest in the infrared continua of quasars, however few published colours exist in the literature. The only major compilation of infrared data out to 2.2 μ is that of Oke et al. (1970). The intrinsic faintness of the sources prevented the acquisition of significant high quality data. This situation is not expected to remain static for very long. The recent introduction of new high sensitivity InSb detectors has made it possible for a large number of sources to be measured, and published data is expected to increase significantly over the next few years.


1962 ◽  
Vol 11 (02) ◽  
pp. 137-143
Author(s):  
M. Schwarzschild

It is perhaps one of the most important characteristics of the past decade in astronomy that the evolution of some major classes of astronomical objects has become accessible to detailed research. The theory of the evolution of individual stars has developed into a substantial body of quantitative investigations. The evolution of galaxies, particularly of our own, has clearly become a subject for serious research. Even the history of the solar system, this close-by intriguing puzzle, may soon make the transition from being a subject of speculation to being a subject of detailed study in view of the fast flow of new data obtained with new techniques, including space-craft.


1997 ◽  
Vol 161 ◽  
pp. 611-621
Author(s):  
Guillermo A. Lemarchand ◽  
Fernando R. Colomb ◽  
E. Eduardo Hurrell ◽  
Juan Carlos Olalde

AbstractProject META II, a full sky survey for artificial narrow-band signals, has been conducted from one of the two 30-m radiotelescopes of the Instituto Argentino de Radioastronomía (IAR). The search was performed near the 1420 Mhz line of neutral hydrogen, using a 8.4 million channels Fourier spectrometer of 0.05 Hz resolution and 400 kHz instantaneous bandwidth. The observing frequency was corrected both for motions with respect to three astronomical inertial frames, and for the effect of Earths rotation, which provides a characteristic changing signature for narrow-band signals of extraterrestrial origin. Among the 2 × 1013spectral channels analyzed, 29 extra-statistical narrow-band events were found, exceeding the average threshold of 1.7 × 10−23Wm−2. The strongest signals that survive culling for terrestrial interference lie in or near the galactic plane. A description of the project META II observing scheme and results is made as well as the possible interpretation of the results using the Cordes-Lazio-Sagan model based in interstellar scattering theory.


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