Abstract
We present a further investigation of the periodogram resulting from the photometric data by Rodríguez et al. (1997) for comet C/1995 O1 Hale–Bopp and interpret that the main period in the data is 11.23 ± 0.01 h, but not 7.19 days. The latter is now attributed to an alias of the 11.23-h period. Assuming that the periodicity observed in the photometry is the solar day, the 11.23-h period is consistent with estimates of the sidereal rotation period by Farnham et al. (1998), and Jorda et al. (1997–1999) provided that the obliquity of the comet‘s equatorial plane to its orbital plane is larger than 75° and 80°, respectively. This result is in agreement with estimates of the obliquity by Sekanina (1997–1999) and Jorda et al. (1998). A weaker periodic signal in the light curve could be 5.48 ± 0.01 h, but we suggest that this is an alias of a 3.25 ± 0.01 h period of unknown origin.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Farnham, T. L., Schleicher, D. G., Blount, E. A. and Ford, E.: 1998, ‘The Rotation Period of Comet Hale–Bopp (1995 O1)’, First International Conference on Comet Hale–Bopp, Tenerife, 2–5 February.
Jorda, L., Rembor, K., Lecacheux, J., Colom, P., Colas, F., Frappa, E., and Lara, L. M.: 1997–1999, ’The Rotational Parameters of Hale–Bopp (C/1995 O1) from Observations of the Dust Jets at Pic du Midi Observatory’, Earth, Moon, and Planets 77, 167–180.
Kidger, M., Sabalisk, N., Santos, P., Serra-Ricart, M., Licandro, J., Bellot, L., Casas, R., Gomez, A., Torres-Chico, R., and Oscoz, A.: 1998, ‘Recursive Jet Activity of Comet 1995 O1 (Hale–Bopp) during 1995. Evidence for a Complex Rotation’, First International Conference on Comet Hale–Bopp , Tenerife , 2–5 February.
Licandro, J., Sabalisk, N., Santos, P., Serra, M., Kidger, M., Bellot, L., Casas, R., Gomez, A., Jorda, L., Tozzi, G. P., Ossip, D., Boehnhardt, H., Goetz, B., and West, R.: 1998, ‘The Rotation Period of Comet 1995 O1 (Hale–Bopp) at Perihelion’, First International Conference on Comet Hale–Bopp , Tenerife , 2–5 February.
Lomb, N. R.: 1976, ‘Least Squares Frequency Analysis of Unequally Spaced Data’, Astrophysics and Space Science 39, 447–462.
Press, W. H. and Rybicki, G. B.: 1989, ‘Fast Algorithm for Spectral Analysis of Unevenly Sampled Data’, Astrophys. J. 338, 277–280.
Press, W. H., Teukolsky S. A., Vetterling, W. T., and Flannery, B. P.: 1992, Numerical Recipes in FORTRAN, Cambridge University Press.
Rodríguez E., Ortiz, J. L., López-González, M. J., Rolland, A., Hobart, M. A., Sánchez-Blanco, E., Gutiérrez, P. J., and López-Moreno, J. J.: 1997, ‘Short-Term Variability in Comet C/1995 O1 Hale–Bopp’, Astron. Astrophys. 324L61–64.
Rodríguez E., Rolland, A., López-González, M. J., and Costa, V.: 1998, Extreme Amplitude Variations in 28 And. Astron. Astrophys., submitted.
Sekanina, Z.: 1998, ‘Modeling the Diurnal Evolution of a Dust Feature in Comet Hale–Bopp (1995 O1)’, Astrophys. J., in press.
Sekanina, Z.: 1997–1999, ‘Detection of a Satellite Orbiting the Nucleus of Comet Hale–Bopp (C/1995 O1)’, Earth, Moon, and Planets 77, 155–163.
Serra-Ricart, M., Licandro, J., Santos, P., Casas, R., Kidger, M., Bellot, L., Gómez, A., Torres-Chico, R., Oscoz, A., Jorda, L., and Denicolo, G.: 1998, ‘The Spin Axis Position of Comet 1995 O1 (Hale–Bopp)’, First International Conference on Comet Hale-Bopp, Tenerife, 2–5 February.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ortiz, J.L., Rodríguez, E. The Rotation Of Comet C/1995 O1 Hale–Bopp From Inner Coma Photometry. Earth, Moon, and Planets 77, 207–215 (1997). https://doi.org/10.1023/A:1006295116299
Issue Date:
DOI: https://doi.org/10.1023/A:1006295116299