• IPAC

IC 2118/Rebull


Young Stars in IC 2118: Using Spitzer Space Telescope infrared images to find newly forming stars in the Witch Head nebula (IC2118) and using optical data to determine their masses and ages and to see their relationship to the interstellar medium and to other similar star forming regions.


IC 2118, the Witch Head Nebula (~210 parsecs), is a star forming region located near the supergiant star Rigel in the constellation Orion. Kun et al. (2004, A&A, 418, 89) have determined that IC 2118 is on the near side of the Orion-Eridanus Super Bubble and that stellar winds from the Orion OB1 association may be triggering new star formation in the nebula. We propose using IRAC and MIPS to reexamine a small dense region of this nebula where Kun et al. have spectroscopically identified three 2MASS sources as T Tauri stars embedded in the cloud. Previous all-sky surveys, including both IRAS and 2MASS, have included this region, but not to the resolution that Spitzer can provide, and there are few studies of this particular region in the literature.

Our team proposes to use IRAC and MIPS observations to (1) investigate star formation, (2) look for likely cluster member stars with infrared excesses, and characterize this young star population by obtaining their colors and therefore estimates of masses and ages, (3) study the distribution of stars, their relationship to the ISM, and the possibilities of triggered star formation, (4) compare the young star population, distribution, and age to other similar sites of star formation, e.g., IC 1396 and (5) produce a dramatic image of the interstellar medium in the region surrounding IC 2118. Since this region is in the Orion constellation near the bright star Rigel, it provides additional appeal to students and the general public.

Participant Educator


Mr. Tony Maranto

Phillips Exeter Academy, Exeter, New Hampshire

Participant Educator


Ms. Theresa Roelofsen Moody

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



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