• IPAC

Iron Stars/Howell and Hoard


Observing Iron Stars with Spitzer: Using Spitzer Space Telescope images to characterize dust around two stars with unusual iron signatures in their optical spectra.


Only two so-called Iron stars exist: XX Oph and AS 325. XX Oph was first observed in 1924 by Merrill. He noted strong, doubly ionized iron emission lines were present in the spectra, thus the name iron star. AS325 was noted to be a similar type object by Howell and Bopp (1982). Further observations of both stars have led to the development of a model (Cool et al., 2005) for both stars which explains the optical emission lines and that the stars consist of two separate stars, possibly in a binary.

The current model has each Iron Star composed of a Be star and a late type (supergiant) companion separated by 1-2 thousand AU. The the interaction of the Be wind with the mass loss from the red star and the dust/gas remnant cocoon surrounding them both. We plan to use Spitzer to observe the dust environment in the star AS325.

Participant Educator


Mr. Lauren Chapple

Traverse City East Junior High School, Traverse City, Michigan

Participant Educator


Participant Educator


Ms. Theresa Roelofsen Moody

Bassick High School, Bridgeport, Connecticut New Jersey Astronomy Center for Education, Raritan Valley Community College, Somerville, New Jersey



  • April-May 2006 updates for NITARP April 15, 2006
    • The Iron Star group had a successful visit to the SSC to reduce their Spitzer data for AS 325.
    • Cynthia Weehler and one of her students, Jessica Herrera, discussed their involvement with the Spitzer Research Program for Teachers and Students during an interview on Texas Public Radio. The station has an estimated audience of 70,000.
  • October 2005 updates for NITARP

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