AAS 207th Meeting, 8-12 January 2006
Session 74 Planets in Binary Star Systems, Young Stars and Jets
Poster, Tuesday, 9:20am-6:30pm, January 10, 2006, Exhibit Hall

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[74.11] Stellar Rotation and Variability in IC 348 and Indication of a 4.75 Year Period for the Unique, Apparently Eclipsing Pre-Main Sequence Star HMW 15

S. C. J. Nordhagen (Middlebury College), K. L. Rhode, W. Herbst, E. C. Williams (Wesleyan U.)

During the past two years of a seven-year photometric variability study of the young stellar cluster IC 348, numerous periodically variable T Tauri stars were discovered, bringing the total number of identified periodic variables in IC 348 to 69, or about 45 % of all cluster stars observed by us. This includes data from Herbst, Maley & Williams (2000, AJ 120, 394), Cohen, Herbst & Williams (2004, AJ 127, 1602) and Littlefair et al. (2005 MNRAS 358, 341). In addition to these photometric data, spectra of 30 cluster members were obtained with the WIYN 3.5m telescope and used to calculate radial velocities and v sin i rotation measurements, offering a generally complementary view of stellar rotation in IC 348. A mean heliocentric radial velocity for the cluster has been determined, and two radial velocity outliers discovered, which are possible spectroscopic binaries. The distribution of rotation periods, their relationship to v sin i measurements and the implications of these results for the rotation and radii of pre-main sequence stars in IC 348 will be presented. In addition, we discuss the recent behavior of the peculiar variable HMW 15 (Cohen, Herbst & Williams 2003 ApJ 596, L243), which now appears to be undergoing a periodic eclipse on a time scale of 4.75 years. We discuss possible origins for this extraordinarily long periodicity. S. Nordhagen was an undergraduate summer student at Wesleyan University, sponsored by the Keck Northeast Astronomy Consortium. Their REU program is supported by NSF grant AST-0353997.


The author(s) of this abstract have provided an email address for comments about the abstract: snordhag@middlebury.edu

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