scholarly journals Detailed Studies of IPHAS sources. II. Sab 19, a true planetary nebula and its mimic crossing the Perseus Arm.

2020 ◽  
Author(s):  
M A Guerrero ◽  
R Ortiz ◽  
L Sabin ◽  
G Ramos-Larios ◽  
E J Alfaro
Keyword(s):  
Radial Velocity ◽  
Emission Line ◽  
Planetary Nebula ◽  
Central Star ◽  
High Dispersion ◽  
Velocity Shift ◽  
Optical Images ◽  
External Shell ◽  
Low Mass ◽  
Perseus Arm

Abstract The INT Photometric Hα Survey (IPHAS) has provided us with a number of new-emission line sources, among which planetary nebulae (PNe) constitute an important fraction. Here we present a detailed analysis of the IPHAS nebula Sab 19 (IPHASX J055242.8+262116) based on radio, infrared, and optical images and intermediate- and high-dispersion longslit spectra. Sab 19 consists of a roundish 0.10 pc in radius double-shell nebula surrounded by a much larger 2.8 pc in radius external shell with a prominent H-shaped filament. We confirm the nature of the main nebula as a PN whose sub-solar N/O ratio abundances, low ionized mass, peculiar radial velocity, and low-mass central star allow us to catalog it as a type III PN. Apparently, the progenitor star of Sab 19 became a PN when crossing the Perseus Arm during a brief visit of a few Myr. The higher N/O ratio and velocity shift ≃40  km s−1 of the external shell with respect to the main nebula and its large ionized mass suggest that it is not truly associated with Sab 19, but it is rather dominated by a Strömgren zone in the interstellar medium ionized by the PN central star.

scholarly journals Radial Velocity of the Central Star of NGC 1514

1968 ◽  
Vol 34 ◽  
pp. 329-329
Author(s):  
A. Mammano ◽  
R. Margoni ◽  
M. Perinotto
Keyword(s):  
Radial Velocity ◽  
Planetary Nebula ◽  
Central Star ◽  
Spectroscopic Observations ◽  
Binary Hypothesis

We would like to report on some spectroscopic observations made of the central star of the planetary nebula NGC 1514, which we think can support the binary hypothesis now advanced by Kohoutek.

scholarly journals Variable Spectra of IC 4997 and NGC 6572

1993 ◽  
Vol 155 ◽  
pp. 488-488
Author(s):  
Siek Hyung ◽  
Lawrence H. Aller ◽  
Walter A. Feibelman
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
Line Intensity ◽  
Planetary Nebula ◽  
Radiative Flux ◽  
Gradual Decrease ◽  
High Dispersion ◽  
Echelle Spectrograph

Variability of the [OIII]4363/4340 H γ ratio in IC 4007 was established in 1956 by William Liller and L.H. Aller who attributed the changes to a gradual decrease of electron density with time. Subsequent 4363/4340 ratio fluctuations negated this explanation. Ferland pointed out that small changes in the radiative flux of the Planetary nebula nucleus (PNN) could explains the variations. Our pervious study emphasized IUE observations, here we compare high dispersion spectra obtained with the Hamilton Echelle Spectrograph with previous measurements to asses line intensity variations. Emission line variability in PNN spectra as noted by Mendez et al. (1988) and by other for HeII 4686 in NGC 6572 may offer significant clues. PNN 4686 appeared by 1990 in IC 4997. Possibly both of these PNN may be evolving into Wolf-Rayet objects, but this development does not necessarily imply that the nebular excitation will increase with time.

scholarly journals On the Photometric Behaviour of the Central Star of the Planetary Nebula Sh2–71

1993 ◽  
Vol 155 ◽  
pp. 399-399
Author(s):  
J. Jurcsik
Keyword(s):  
Planetary Nebula ◽  
Central Star ◽  
High Dispersion ◽  
Photometric System ◽  
Colour Variation ◽  
Variable Amplitude ◽  
Central Object ◽  
Spectroscopic Observations ◽  
Exciting Source ◽  
Lower Luminosity

The central star of Sh2–71 was observed with the lm telescope using UBV(RI)c photometric system at Konkoly Observatory in the seasons of 1990–92. A period of 68d.06 was found with variable amplitude and/or lightcurve shape. The amplitude is high, close to 1 magnitude. On the basis of old photographic observations (Kohoutek 1979) this period has not changed during the century. No significant colour variation was detected, but the nebular contamination should distort the colour curves. According to the five colour data the central object is a highly reddened B5 dwarf about 1700 pc distant. The nebular properties, however, indicate an evolved, higher mass, lower luminosity exciting source, therefore it is plausible to regard the central object as a binary. The light variation might be caused by obscuration of the B star by outflowing matter from the true nucleus. Bipolar outflow of 3″ dimension has been detected on high dispersion Hα spectra of the central star (Sabbadin et al. 1985; Cuesta et al. 1990). Further spectroscopic observations are highly needed in order to find the exact description of the system.

scholarly journals Planetary nebulae with Wolf-Rayet-type central stars - II. Dissecting the compact planetary nebula M 2-31 with GTC MEGARA

2021 ◽  
Author(s):  
J S Rechy-García ◽  
J A Toalá ◽  
S Cazzoli ◽  
M A Guerrero ◽  
L Sabin ◽  
...  
Keyword(s):  
Planetary Nebula ◽  
Spectral Properties ◽  
Narrow Band ◽  
Central Star ◽  
Comprehensive Analysis ◽  
High Dispersion ◽  
Medium Resolution ◽  
First Time ◽  
Integral Field ◽  
Central Stars

Abstract We present a comprehensive analysis of the compact planetary nebula M 2-31 investigating its spectral properties, spatio-kinematical structure and chemical composition using GTC MEGARA integral field spectroscopic observations and NOT ALFOSC medium-resolution spectra and narrow-band images. The GTC MEGARA high-dispersion observations have remarkable tomographic capabilities, producing an unprecedented view of the morphology and kinematics of M 2-31 that discloses a fast spectroscopic bipolar outflow along position angles 50○ and 230○, an extended shell and a toroidal structure or waist surrounding the central star perpendicularly aligned with the fast outflows. These observations also show that the C ii emission is confined in the central region and enclosed by the [N ii] emission. This is the first time that the spatial segregation revealed by a 2D map of the C ii line implies the presence of multiple plasma components. The deep NOT ALFOSC observations allowed us to detect broad WR features from the central star of M 2-31, including previously undetected broad O vi lines that suggest a reclassification as a [WO4]-type star.

scholarly journals Fading and variations in the spectrum of the central star of the young Planetary Nebula SAO 244567 (Hen 1357)

1997 ◽  
Vol 180 ◽  
pp. 123-124
Author(s):  
M. Parthasarathy ◽  
P. Garcia-Lario ◽  
D. de Martino ◽  
S. R. Pottasch ◽  
S.F. de Cordoba
Keyword(s):  
Emission Line ◽  
Planetary Nebula ◽  
Optical Spectrum ◽  
Central Star ◽  
Alpha Emission

SAO 244567 (= Hen 1357) is a very young planetary nebula. It was discovered by Parthasarathy et al. (1993, A and A 267, L19). Based on the spectrum obtained around 1950 Henize (1976, ApJ Suppl 30, 491) classified it as a B or A type H-alpha emission line star. The optical spectrum of SAO 244567 obtained in 1971 shows that it was a post-AGB B1 supergiant at that time. It has turned into a planetary nebula within the last 20 years (Parthasarathy et al. 1995, A and A 300, L25).

scholarly journals The very fast evolution of Sakurai's object

2016 ◽  
Vol 12 (S323) ◽  
pp. 380-381 ◽  
Author(s):  
G. C. Van de Steene ◽  
P. A. M. van Hoof ◽  
S. Kimeswenger ◽  
A. A. Zijlstra ◽  
A. Avison ◽  
...  
Keyword(s):  
High Resolution ◽  
Emission Line ◽  
Planetary Nebula ◽  
Temporal Evolution ◽  
Optical Emission ◽  
Central Star ◽  
Evolutionary Models ◽  
Thermal Pulse ◽  
Emission Line Spectrum ◽  
Fast Evolution

AbstractV4334 Sgr (a.k.a. Sakurai's object) is the central star of an old planetary nebula that underwent a very late thermal pulse a few years before its discovery in 1996. We have been monitoring the evolution of the optical emission line spectrum since 2001. The goal is to improve the evolutionary models by constraining them with the temporal evolution of the central star temperature. In addition the high resolution spectral observations obtained by X-shooter and ALMA show the temporal evolution of the different morphological components.

scholarly journals The post-common-envelope binary central star of the planetary nebula PN G283.7−05.1

2020 ◽  
Vol 642 ◽  
pp. A108 ◽  
Author(s):  
D. Jones ◽  
H. M. J. Boffin ◽  
J. Hibbert ◽  
T. Steinmetz ◽  
R. Wesson ◽  
...  
Keyword(s):  
Planetary Nebula ◽  
Main Sequence ◽  
Planetary Nebulae ◽  
Central Star ◽  
Radial Velocity Curve ◽  
Common Envelope ◽  
Low Mass ◽  
Red Giant ◽  
Model Temperature ◽  
Temperature Surface

We present the discovery and characterisation of the post-common-envelope central star system in the planetary nebula PN G283.7−05.1. Deep images taken as part of the POPIPlaN survey indicate that the nebula may possess a bipolar morphology similar to other post-common-envelope planetary nebulae. Simultaneous light and radial velocity curve modelling reveals that the newly discovered binary system comprises a highly irradiated M-type main-sequence star in a 5.9-hour orbit with a hot pre-white dwarf. The nebular progenitor is found to have a particularly low mass of around 0.4 M⊙, making PN G283.7−05.1 one of only a handful of candidate planetary nebulae that is the product of a common-envelope event while still on the red giant branch. In addition to its low mass, the model temperature, surface gravity, and luminosity are all found to be consistent with the observed stellar and nebular spectra through comparison with model atmospheres and photoionisation modelling. However, the high temperature (Teff ∼ 95 kK) and high luminosity of the central star of the nebula are not consistent with post-RGB evolutionary tracks.

Hα and Hβ Imaging of the Planetary Nebula NGC 6302

1990 ◽  
Vol 8 (04) ◽  
pp. 360-363 ◽  
Author(s):  
Michael C. B. Ashley
Keyword(s):  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Central Star ◽  
Infrared Observations ◽  
Dust Extinction ◽  
The Core ◽  
Optical Images ◽  
5 Ghz ◽  
Good Agreement

Abstract NGC 6302 is one of the highest excitation planetary nebulae known. It has an obscured central star with a temperature estimated at 430,000 K. We present here CCD images in Hα and Hβ of NGC 6302, and interpret the differences between the images as being due to extinction caused by dust within the nebula. The dust appears to be concentrated in the core, as expected from infrared observations. There is no evidence of patchy foreground extinction, although there is a slight difference in the average extinction between the eastern and western lobes of the nebula. A comparison between the Hα image and a 5 GHz map gives a dust extinction of ΔAV~3.5 to the central star. The outer contours of the 5 GHz map are not in good agreement with the optical images, and further observations at this frequency would be useful.

scholarly journals The post-common-envelope binary central star of the planetary nebula ETHOS 1

2020 ◽  
Vol 498 (4) ◽  
pp. 6005-6012
Author(s):  
James Munday ◽  
David Jones ◽  
Jorge García-Rojas ◽  
Henri M J Boffin ◽  
Brent Miszalski ◽  
...  
Keyword(s):  
Planetary Nebula ◽  
Main Sequence ◽  
Orbital Plane ◽  
Central Star ◽  
Low Mass Stars ◽  
Common Envelope ◽  
First Case ◽  
Kinematic Modelling ◽  
Low Mass ◽  
The Common

ABSTRACT We present a detailed study of the binary central star of the planetary nebula ETHOS 1 (PN G068.1+11.0). Simultaneous modelling of light and radial velocity curves reveals the binary to comprise a hot and massive pre-white dwarf with an M-type main-sequence companion. A good fit to the observations was found with a companion that follows expected mass–temperature–radius relationships for low-mass stars, indicating that despite being highly irradiated, it is consistent with not being significantly hotter or larger than a typical star of the same mass. Previous modelling indicated that ETHOS 1 may comprise the first case where the orbital plane of the central binary does not lie perpendicular to the nebular symmetry axis, at odds with the expectation that the common envelope is ejected in the orbital plane. We find no evidence for such a discrepancy, deriving a binary inclination in agreement with that of the nebula as determined by spatio-kinematic modelling. This makes ETHOS 1 the ninth post-common-envelope planetary nebula in which the binary orbital and nebular symmetry axes have been shown to be aligned, with as yet no known counter-examples. The probability of finding such a correlation by chance is now less than 0.000 02 per cent.

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