Did η Carinae's Weigelt Blobs Originate circa 1941?
Abstract
We report astrometric measurements of η Carinae's Weigelt blobs C and D (also known as speckle objects C and D) derived from observations with the Hubble Space Telescope Wide Field Planetary Camera 2. Using three epochs of data with a temporal baseline of 5.9 yr, we measure blob D's proper motion relative to the central star to be 4.4+/-1.4 mas yr-1, implying a date of origin of 1934.1+16.0-31.7. Similarly, using two epochs with a 1.7 yr baseline, we measure blob C's relative proper motion to be 3.8+/-5.6 mas yr-1, indicating a probability of ejection after 1910 of ~60% we view this as confirming the more accurate blob D results (assuming coevality), with a combined post-1910 ejection indicated at a ~90% confidence level. The blob D date roughly coincides with the sudden brightening of the central star observed in 1941 and provides a possible explanation for the onset of certain narrow spectral features, associated with the Weigelt blobs, that have been observed only since the mid-1940s. We propose that the ejection of Weigelt blobs C and D was related to this 1941 event.
- Publication:
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The Astronomical Journal
- Pub Date:
- February 2004
- DOI:
- 10.1086/380941
- Bibcode:
- 2004AJ....127.1052D
- Keywords:
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- Astrometry;
- ISM: Jets and Outflows;
- Stars: Individual: Constellation Name: η Carinae;
- Stars: Variables: Other