Spectrum of short-periodic comet 2P/Encke in the apparition of 2003

1Shubina, OS, 2Borisov, NV, 3Ivanova, OV, 4Rosenbush, VK
1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
2Special Astrophysical Observatory, Nizhnij Arkhyz, Russia
3Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine, Astronomical Institute of Slovak Academy of Sciences, Tatranská Lomnica, Slovak Republic
4Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine, Astronomical Observatory of Taras Shevchenko Kyiv National University
Kinemat. fiz. nebesnyh tel (Online) 2018, 34(4):67-80
Start Page: Dynamics and Physics of Solar System Bodies
Language: Russian
Abstract: 

We analysed the spectra of comet 2P/Encke obtained on November 15 and 22, 2003 within the wavelength ranges 410—580 nm and 560—720 nm, with the help of the UAGS spectrograph on the 1-m telescope Zeiss-1000 of Special Astrophysical Observatory, Russian Academy of Sciences. The spectral resolution is about 0.5 nm. In the cometary coma, the emission bands of C2, CN, CH, and NH2 molecules are detected. The normalized spectral gradient of reflectivity is 11.95 ± 3.45 % per 100 nm and 7.90 ± 2.81 % per 100 nm in the wavelength bands 450—567 nm and 565—676 nm, respectively. The values of parameter Afρ = 77 ± 9, 81 ± 9, and 79 ± 9 cm for the BC, GC, and RC continuum filters, respectively, reflect a very low dust content in comet Enke. Using the Haser model, we determined the production rate of gas molecules: 1.12·1025 mol/s for C2 (Δν = 0) and 3.82·1024 mol/s for NH2 (0,10,0).

Keywords: comet, dust, spectrum
References: 

1.O. V. Dobrovol’skii, Comets (Nauka, Moscow, 1996) [in Russian].

2.T. A. Kartashova and N. M. Chunakova, “Spectral transparency of the atmosphere at the Special Astrophysical Observatory of the Academy of Sciences of USSR in 1974–1976,” Astrofiz. Issled. Izv. Spets. Astrofiz. Obs. 10, 44–52 (1978).

3.M. F. A’Hearn, P. V. Birch, P. D. Feldman, and R. L. Millis, “Comet Encke: Gas production and light curve,” Icarus 64, 1–10 (1985).
https://doi.org/10.1016/0019-1035(85)90033-8

4.M. F. A’Hearn, R. L. Millis, and P. V. Birch, “Gas and dust in some periodic comets,” Astron. J. 84, 570–579 (1979).
https://doi.org/10.1086/112452

5.M. F. A’Hearn, R. L. Millis, D. G. Schleicher, et al., “The ensemble properties of comets: Results from narrowband photometry of 85 comets, 1976–1992,” Icarus 118, 223–270 (1995).
https://doi.org/10.1006/icar.1995.1190

6.M. F. A’Hearn, R. L. Millis, and D. T. Thompson, “The disappearance of OH from comet Encke,” Icarus 55, 250–258 (1983).
https://doi.org/10.1016/0019-1035(83)90080-5

7.M. F. A’Hearn, D. G. Schleicher, R. L. Millis, et al., “Comet Bowell 1980b,” Astron. J. 89, 579–591 (1984).
https://doi.org/10.1086/113552

8.S. Arpigny, Comet Spectra. Comets. Scientific Data and Missions (Univ. of Arizona Press, Tucson, AZ, 1972), pp. 84–111.

9.C. Arpigny, Interpretation of Comet Spectra. The Study of Comets (U.S. Government Printing Office, Washington, DC, 1976), pp. 797–838.

10.M. J. S. Belton, N. H. Samarasinha, Y. R. Fernandez, and K. J. Meech, “The excited spin state of comet 2P/Encke./cams,” 175, 181–193 (2005).

11.A. L. Cochran, E. S. Barker, T. F. Ramseyer, and A. D. Storrs, “The McDonald observatory faint comet survey: Gas production in 17 comets,” Icarus 98, 151–162 (1992).
https://doi.org/10.1016/0019-1035(92)90086-M

12.G. Dorman, D. M. Pierce, and A. L. Cochran, “The spatial distribution of Sg, S3, and NH in comet 2P/Encke,” Astrophys. J. 778, 140–154 (2013).
https://doi.org/10.1088/0004-637X/778/2/140

13.K. Dressier and D. A. Ramsay, “The electronic absorption spectra of NH2 and ND2,” Phil. Trans. R. Soc. London A. 251, 553–604 (1959).
https://doi.org/10.1098/rsta.1959.0011

14.Y. R. Fernandez, S. M. Lisse, H. U. Kaufl, et al., “Physical properties of nucleus of comet 2P/Encke,” Icarus 147, 145–160 (2000).
https://doi.org/10.1006/icar.2000.6431

15.R. D. Gehrz, E. P. Ney, J. Piscitelli, et al., “Infrared photometry and spectroscopy of comet P/Encke,” Icarus 80, 280–288 (1989).
https://doi.org/10.1016/0019-1035(89)90139-5

16.L. Haser, “Distribution d’intensite dans la tete d’une comete,” Bull. Cl. Sci., Acad. R. Belg. 43, 740–750 (1957).MathSciNet

17.D. Jewitt, “From Kuiper Belt object to cometary nucleus: The missing ultrared matter,” Astron. J. 123, 1039–1049 (2002).
https://doi.org/10.1086/338692

18.D. Jewitt, “Looking through the HIPPO: Nucleus and dust in comet 2P/Encke,” Astron. J. 128, 3061–3069 (2004).
https://doi.org/10.1086/425888

19.K. Jockers, S. Szutowicz, G. Villanueva, et al., “Gas and dust in Comet 2P/Encke observed in the visual and submillimeter wavelength ranges,” Kinematika Fiz. Nebesnykh Tel, Suppl. 5, 458–164 (2005).

20.L. E. Langland-Shula and G. H. Smith, “Comet classification with new methods for gas and dust spectroscopy,” Icarus 213, 280–322 (2011).
https://doi.org/10.1016/j.icarus.2011.02.007

21.J. Luque and D. R. Crosley, “LIFBASE: Database and spectral simulation program (version 1.5),” SRI International Report No. MP 99-009 (1999).

22.B. G. Marsden and Z. Sekanina, “Comets and nongravitational forces. VI. Periodic comet Encke 1786–1971,” Astron. J. 79, 413–419 (1974).
https://doi.org/10.1086/111560

23.H. Neckel and D. Labs, “The solar radiation between 3300 and 12500 A,” Sol. Phys. 90, 205–258 (1984).
https://doi.org/10.1007/BF00173953

24.R. L. Newburn and H. Spinrad, “Spectrophotometry of seventeen comets. II — The continuum,” Astron J. 90, 2591–2608 (1985).
https://doi.org/10.1086/113965

25.J. B. Oke, “Faint spectrophotometric standard stars,” Astron. J. 99, 1621–1631 (1990).
https://doi.org/10.1086/115444

26.D. J. Osip, D. G. Schleicher, and R. L. Millis, “Comets: Groundbased observations of spacecraft mission candidates,” Icarus 98, 115–124 (1992).
https://doi.org/10.1016/0019-1035(92)90212-P

27.J. G. Phillips, S. P. Davis, The Swan System of the Ci Molecule (Univ. of California Press, Berkeley, 2002).

28.W. T. Reach, M. V. Sykes, D. Lien, and J. K. Davies, “The formation of Encke meteoroids and dust trail,” Icarus 148, 80–94 (2000).
https://doi.org/10.1006/icar.2000.6478

29.L. Saba, M. T. Capria, and G. Cremonese, “High-resolution observations of 2P/Encke comet: Preliminary results,” Mem. Soc. Astron. Ital. Suppl. 6, 137–141 (2005).

30.Z. Sekanina, “Fan-shaped coma, orientation of rotation axis, and surface structure of a cometary nucleus. I — Test of a model on four comets,” Icarus 37, 420–442 (1979).
https://doi.org/10.1016/0019-1035(79)90006-X

31.Z. Sekanina and H. E. Schuster, “Dust from periodic comet Encke: Large grains in short supply,” Astron. Astrophys. 68, 429–435 (1978).

32.F. L. Whipple, “A comet model. I. The acceleration of comet Encke,” Astrophys. J. 111, 375–394 (1950).
https://doi.org/10.1086/145272