Results 31 to 40 of about 6,433 (179)

Binary planetary nebulae nuclei towards the Galactic bulge. II. A penchant for bipolarity and low-ionisation structures

, 2009
Considerable effort has been applied towards understanding the precise shaping mechanisms responsible for the diverse range of morphologies exhibited by planetary nebulae (PNe).
Acker, A., Miszalski, B., Moffat, A. F. J., Parker, Q. A.   +3 more
core   +1 more source

Quantitative classification of WR nuclei of planetary nebulae [PDF]

Astronomy & Astrophysics, 2003
We analyse 42 emission-line nuclei of Planetary Nebulae (PNe), in the framework of a large spectrophotometric survey of (WC) nuclei of PNe conducted since 1994, using low/medium resolution spectra obtained at ESO and at OHP. We construct a grid of selected line-intensities (normalized to C iv-5806 A= 100) ordered by decreasing ionisation potential ...
A. Acker, C. Neiner
openaire   +1 more source

In Search of Possible Associations between Planetary Nebulae and Open Clusters

, 2007
We consider the possibility of cluster membership for 13 planetary nebulae that are located in close proximity to open clusters lying in their lines of sight.
Akhundova G. V., Andrews A. D., Barkhatova K. A., Bertelli G., Burki G., Cahn J. H., Cazetta J. O., Cuisinier F., Cutri R. M., Dambis A. K., Daniel J. Majaess, David G. Turner, David J. Lane, Glushkova E. V., Glushkova E. V., Hasegawa T., Jennens P. A., Kholopov P. N., Koester D., Kwok S., Mal'kov Y. F., Mallik D. C. V., Mermilliod J.-C., Mermilliod J.-C., Meynet G., Moffat A. F. J., Moitinho A., Neckel Th., Osterbrock D. E., Pena M., Peton-Jonas D., Svolopoulos S. N., Tifft W. G., Turner D. G., Tylenda R., Walker A. R., Weidemann V., Zijlstra A. A., Ziznovsky J.   +38 more
core   +1 more source

Are planetary nebulae derived from multiple evolutionary scenarios? [PDF]

, 2011
Our understanding of planetary nebulae has been significantly enhanced as a result of several recent large surveys (Parker et al., these proceedings). These new discoveries suggest that the `PN phenomenon' is in fact more heterogeneous than previously ...
Althaus, Danehkar, David J. Frew, De Marco, Fogel, Frankowski, Gesicki, Girard, Hamann, Lepo, Miszalski, Quentin A. Parker, Szyszka, Todt, Todt, Tylenda   +15 more
core   +1 more source

Whither or Wither the Sulfur Anomaly in Planetary Nebulae?

The Astrophysical Journal Letters
We present a thorough investigation of the long-standing sulfur anomaly enigma. Our analysis uses chemical abundances from the most extensive data set available for 126 planetary nebulae (PNs) with improved accuracy and reduced uncertainties from a 10° ×
Shuyu Tan, Quentin A. Parker
doaj   +1 more source

Time-Resolved CCD-Photometry of Planetary Nebula Nuclei [PDF]

Symposium - International Astronomical Union, 1993
The enormous potential of direct imaging CCDs with respect to stellar photometry was soon discovered after these detectors became available for standard instrumentation at modern telescopes. Among favourable properties like high quantum efficiency, linearity, and large dynamic range the multiplexing advantage of the 2-dimensional detector has permitted
M. M. Roth, T. Soffner, W. Mitsch
openaire   +1 more source

Constraints on Noble Gas Variability in OIB and MORB From Non‐Equilibrium Magmatic Degassing Models

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 3, March 2026.
Abstract Noble gas concentrations in ocean island basalts (OIB) and mid‐ocean ridge basalts (MORB) are affected by degassing processes, obscuring their pre‐eruptive characteristics. Degassing corrections commonly assume near‐equilibrium partitioning of noble gases between melt and vapor.
Thomas Williams, Stephen Parman, Christian Huber   +2 more
wiley   +1 more source

The Properties of Planetary Nebulae Nuclei: Stellar Winds [PDF]

Symposium - International Astronomical Union, 1993
We present IUE observations of some nuclei of Planetary Nebulae. From these data we derive the stellar photospheric parameters (Teff Lbol, log g), and the wind characteristics (velocity, mass loss rate). Teff, R∗, Lbol are derived from UV low resolution spectra, combining optical and radio data, from Bianchi (1988) or from new IUE data, with the same ...
L. Bianchi, G. De Francesco
openaire   +1 more source

Formation of Asteroid (16) Psyche by a Giant Impact

Journal of Geophysical Research: Planets, Volume 131, Issue 1, January 2026.
Abstract Asteroid (16) Psyche is the largest likely metal‐rich asteroid in the Solar System and the target of the NASA Psyche mission. The mission aims to determine whether the asteroid is the core of a differentiated planetesimal that lost its mantle via a giant impact.
Saverio Cambioni, Benjamin P. Weiss, Namya Baijal, Robert Melikyan, Erik Asphaug, John B. Biersteker, Richard P. Binzel, William F. Bottke, Samuel W. Courville, Linda T. Elkins‐Tanton, David J. Lawrence, José M. G. Merayo, Carol A. Raymond, Mark A. Wieczorek, Maria T. Zuber   +14 more
wiley   +1 more source

The Secular Evolution of Planetary Nebula IC 418 and Its Implications for Carbon Star Formation

The Astrophysical Journal Letters
The rate of stellar evolution can rarely be measured in real time. The fastest evolution (excluding event-driven evolution), where stars may evolve measurably over decades, is during the post–Asymptotic Giant Branch (AGB) phase. In this Letter we provide
Albert A. Zijlstra, Quentin A. Parker
doaj   +1 more source