Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Spectroscopic survey of faint planetary-nebula nuclei – II. The subdwarf O central star of Fr 2-30

Journal Article · · Monthly Notices of the Royal Astronomical Society
 [1];  [2];  [3];  [4]
  1. Pennsylvania State Univ., University Park, PA (United States); Space Telescope Science Institute, Baltimore, MD (United States)
  2. Eberhard Karls Univ. (Germany)
  3. Univ. of Texas, Austin, TX (United States)
  4. Stark Bayou Observatory , Ocean Springs, MS (United States)
+ Show Author Affiliations
Fr 2-30 = PN? G126.8−15.5 is a faint emission nebula, hosting a 14th-mag central star that we identify here for the first time. Deep Hα and [O III] images reveal a roughly elliptical nebula with dimensions of at least 22 arcmin × 14 arcmin, fading into a surrounding network of even fainter emission. Optical spectrograms of the central star show it to have a subdwarf O spectral type, with a Gaia parallax distance of 890 pc. A model-atmosphere analysis gives parameters of Teff = 60 000 K, log g = 6.0, and a low helium content of nHe/nH = 0.0017. The location of the central star in the log g–Teff plane is inconsistent with a post-asymptotic-giant-branch evolutionary status. Two alternatives are that it is a helium-burning post-extreme-horizontal-branch object, or a hydrogen-burning post-red-giant-branch star. In either case, the evolutionary ages are so long that a detectable planetary nebula (PN) should not be present. We find evidence for a variable radial velocity (RV), suggesting that the star is a close binary. However, there are no photometric variations, and the spectral-energy distribution rules out a companion earlier than M2 V. The RVs of the star and surrounding nebula are discordant, and the nebula lacks typical PN morphology. We suggest that Fr 2-30 is a ‘PN mimic’ – the result of a chance encounter between the hot sdO star and an interstellar cloud. However, we note the puzzling fact that there are several nuclei of genuine PNe that are known to be in evolutionary states similar to that of the Fr 2-30 central star.
Research Organization:
US Department of Energy (USDOE), Washington, DC (United States). Office of Science, Sloan Digital Sky Survey (SDSS)
Sponsoring Organization:
Alfred P. Sloan Foundation; Chinese Academy of Sciences; European Space Agency; National Aeronautics and Space Administration (NASA); National Science Foundation (NSF); USDOE; USDOE Office of Science (SC)
OSTI ID:
1984910
Alternate ID(s):
OSTI ID: 2425293
Journal Information:
Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 3 Vol. 523; ISSN 0035-8711; ISSN 1365-2966
Publisher:
Oxford University PressCopyright Statement
Country of Publication:
United States
Language:
English

References (40)

Binaries discovered by the SPY survey journal March 2011
The Gaia mission journal November 2016
Three-dimensional mapping of the local interstellar medium with composite data journal October 2017
Spectral analysis of four surprisingly similar hot hydrogen-rich subdwarf O stars journal January 2018
The population of hot subdwarf stars studied with Gaia : II. The journal January 2019
The population of hot subdwarf stars studied withGaia journal March 2020
High-resolution FUSE and HST ultraviolet spectroscopy of the white dwarf central star of Sh 2-216 journal May 2007
Planetary Nebulae: Observational Properties, Mimics and Diagnostics journal January 2010
PHL 932: When Is a Planetary Nebula Not a Planetary Nebula?
  • Frew, David J.; Madsen, Greg J.; O'Toole, Simon J.
  • Publications of the Astronomical Society of Australia, Vol. 27, Issue 2 https://doi.org/10.1071/AS09043
journal January 2010
An Imaging Survey of Northern Galactic H α Emission with Arcminute Resolution
  • Dennison, Brian; Simonetti, John H.; Topasna, Gregory A.
  • Publications of the Astronomical Society of Australia, Vol. 15, Issue 1 https://doi.org/10.1071/AS98147
journal January 1998
An optimal extraction algorithm for CCD spectroscopy journal June 1986
Planetary nebulae as standard candles. I - Evolutionary models journal April 1989
The relationship between infrared, optical, and ultraviolet extinction journal October 1989
Clues on the hot star content and the ultraviolet output of elliptical galaxies journal November 1990
Ultraviolet Radiation from Evolved Stellar Populations. I. Models journal December 1993
On the Balmer Line Problem journal January 1996
A Spitzer Infrared Spectrograph Spectral Sequence of M, L, and T Dwarfs journal September 2006
The Wide-Field Infrared Survey Explorer (Wise): Mission Description and Initial On-Orbit Performance journal November 2010
The Fourth us Naval Observatory ccd Astrograph Catalog (Ucac4) journal January 2013
Spectroscopic Analysis of hot, Hydrogen-Rich White Dwarfs: the Presence of Metals and the Balmer-Line Problem journal August 2010
The man Behind the Curtain: X-Rays Drive the uv Through nir Variability in the 2013 Active Galactic Nucleus Outburst in ngc 2617 journal May 2014
The Infrared Telescope Facility (Irtf) Spectral Library: cool Stars journal November 2009
Hot Subluminous Stars journal July 2016
The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0 journal August 2017
Planetary Nebulae: Sources of Enlightenment journal February 2022
HASH: the Hong Kong/AAO/Strasbourg Hα planetary nebula database journal July 2016
The post-common-envelope binary central star of the planetary nebula Ou 5: a doubly eclipsing post-red-giant-branch system journal December 2021
Two evolved close binary stars: GALEX J015054.4+310745 and the central star of the planetary nebula Hen 2-84 journal January 2022
Hot white dwarfs and pre-white dwarfs discovered with SALT journal December 2022
Spectroscopic survey of faint planetary-nebula nuclei – I. Six new ‘O vi’ central stars journal February 2023
Planetary nebulae after common-envelope phases initiated by low-mass red giants journal August 2013
Hunting for extremely faint planetary nebulae in the SDSS spectroscopic database journal September 2013
The winds of hydrogen-rich central stars of planetary nebulae journal October 2011
LRS2: design, assembly, testing, and commissioning of the second-generation low-resolution spectrograph for the Hobby-Eberly Telescope conference August 2016
The HETDEX Instrumentation: Hobby–Eberly Telescope Wide-field Upgrade and VIRUS journal December 2021
Hot Subdwarf Stars Identified in Gaia DR2 with Spectra of LAMOST DR6 and DR7. I. Single-lined Spectra journal January 2020
Hot Subdwarf Stars Identified in Gaia DR2 with Spectra of LAMOST DR6 and DR7. II.Kinematics journal July 2020
Full spectrum fitting with photometry in ppxf: non-parametric star formation history, metallicity and the quenching boundary from 3200 LEGA-C galaxies at redshift z~0.8 preprint January 2022
Post-red-giant-branch Planetary Nebulae preprint January 2023
Spectroscopic investigation of old planetaries IV. Model atmosphere analysis text January 1999

Similar Records

Radial velocity variability and the evolution of hot subdwarf stars
Journal Article · Sat Apr 30 20:00:00 EDT 2022 · Astronomy and Astrophysics · OSTI ID:1982328
Dust from evolved stars: a pilot analysis of the AGB to PN transition
Journal Article · Mon Oct 09 20:00:00 EDT 2023 · Monthly Notices of the Royal Astronomical Society · OSTI ID:2203582

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
evolution of stars
planetary nebulae
subdwarfs