Revealing the photodissociation region: HST/NICMOS imaging of NGC 7027

William B. Latter, Aditya Dayal, John H. Bieging, Casey Meakin, Joseph L. Hora, Douglas M. Kelly, A. G.G.M. Tielens

Research output: Contribution to journalArticlepeer-review

73 Scopus citations


We report results from a Hubble Space Telescope (HST) and Near-Infrared Camera and Multiobject Spectrometer (NICMOS) program to study the distribution of hot neutral (molecular hydrogen) and ionized circumstellar material in the young planetary nebulae NGC 7027. HST/NICMOS provided very high spatial resolution imaging in line and continuum emission, and the stability and large dynamic range needed for investigating detailed structures in the circumstellar material. We present dramatic new images of NGC 7027 that have led to a new understanding of the structure in this important planetary nebula. The central star is clearly revealed, providing near-infrared fluxes that are used to directly determine the stellar temperature very accurately (T(black star sing) = 198,000 K). It is found that the photodissociation layer as revealed by near-infrared molecular hydrogen emission is very thin (ΔR ∼ 6 × 1015 cm) and is biconical in shape. The interface region is structured and filamentary, suggesting the existence of hydrodynamic instabilities. We discuss evidence for the presence of one or more highly collimated, off-axis jets that might be present in NGC 7027. The NICMOS data are combined with earlier Hubble Space Telescope data to provide a complete picture of NGC 7027 using the highest spatial resolution data to date. The evolutionary future of NGC 7027 is discussed.

Original languageEnglish (US)
Pages (from-to)783-797
Number of pages15
JournalAstrophysical Journal
Issue number2 PART 1
StatePublished - Aug 20 2000
Externally publishedYes


  • ISM: molecules
  • ISM: structure
  • Molecular processes
  • Planetary nebulae: general
  • Planetary nebulae: individual (NGC 7027)

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Revealing the photodissociation region: HST/NICMOS imaging of NGC 7027'. Together they form a unique fingerprint.

Cite this