Juristische FakultätPhilosophische FakultätHumanwissenschaftliche FakultätWirtschafts- und Sozialwissenschaftliche FakultätMathematisch-Naturwissenschaftliche FakultätUniversität Potsdam
Universität Potsdam
Institut für Physik und Astronomie
Innenhof des Physikgebäudes bei Nacht
Bild: David Gruner

Institut / Details zur Veranstaltung

29.09.: Kolloquium des Instituts: Prof. Dr. Philip Nicholson, Kronoseismology III: An update on Saturn-driven waves in the C rin

In previous work (Hedman & Nicholson [2013] Astron. J. 146, 12; Ibid [2014] MNRAS 444, 1369; French et al.[2016] Icarus, in press) we have identified 9 inward-propagating density waves in Saturn's C ring with outer Lindblad resonances (OLRs) generated by internal oscillations in Saturn. The oscillations involved are sectoral f-modes (ie., fundamental modes with l = m) with m = 1, 2, 3, 4 and 10. In addition, 5 outward-propagating waves between radii of 84,800 and 86,600 km have been identified as density waves driven by 3:2 tesseral resonances with fixed gravitational anomalies within the planet. (See Hedman et al., this conference.) We have now examined additional C ring waves from the catalog of Baillie et al. [2011], in an attempt to identify several weaker and shorter-wavelength waves in the inner C ring. We use a modified version of our previous wavelet-based technique to coadd phase-corrected spectra from multiple occultations, using trial values of `m` and the pattern speed to predict their relative phases. This enables us to detect waves too weak to see in individual occultations. To date, 6 new waves have been identified. Two appear to be due to additional saturnian f-modes, with m = 2 and m = 9. The other 4 waves appear to be a new variety: outward-propagating bending waves driven at outer vertical resonances (OVRs) with Saturn internal oscillations with l = m + 1. We find waves with m = 4, 7, 8 & 9. All of the newly-identified waves are at radii less than 77,000 km and only the m = 4 OVR is near the location predicted by Marley & Porco [1993].
Ort:
Raum 0.108, Haus 28 (Institut fuer Physik)
Zeit:
16:15 Uhr
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