NS  Vol.2 No.11 , November 2010
Is it plausible to expect a close encounter of the Earth with a yet undiscovered astronomical object in the next few years?
Author(s) Lorenzo Iorio
ABSTRACT
We analytically and numerically investigate the possibility that a still undiscovered body X, moving along an unbound hyperbolic path from outside the solar system, may penetrate its inner regions in the next few years posing a threat to the Earth. By conservatively using as initial position of X the lower bounds on the present‐day distance of X dynamically inferred from the gravitational perturbations induced by it on the orbital motions of the planets of the solar system, both the analyses show that, in order to reach the Earth’s orbit in the next 2 yr, X should move at a highly unrealistic speed , whatever its mass is. For example, by assuming for it a solar ( M ) or brown dwarf mass ( ), now at not less than kau (1 kau=1000 astronomical units), v would be of the order of and of the speed of light c, respectively. By assuming larger present‐day distances for X, on the basis of the lacking of direct observational evidences of electromagnetic origin for it, its speed would be even higher. Instead, the fastest solitary massive objects known so far, like hypervelocity stars (HVSs) and supernova remnants (SRs), travel at , having acquired so huge velocities in some of the most violent astrophysical phenomena like interactions with supermassive galactic black holes and supernova explosions. It turns out that the orbit of the Earth would not be macroscopically altered by a close (0.2 au) passage of such an ultrafast body X in the next 2 yr. On the contrary, our planet would be hurled into the space if a Sun‐sized body X would encounter it by moving at . On the other hand, this would imply that such a X should be now at just 20-30 au, contrary to all direct observational and indirect dynamical evidences.

Cite this paper
Iorio, L. (2010) Is it plausible to expect a close encounter of the Earth with a yet undiscovered astronomical object in the next few years?. Natural Science, 2, 1181-1188. doi: 10.4236/ns.2010.211146.
References
[1]   Brown, W.R., Geller, M.J., Kenyon, S.J. and Kurtz, M.J. (2005) Discovery of an unbound hypervelocity star in the milky way halo. The Astrophysical Journal, 62, L33‐L36.

[2]   Edelmann, H., Napiwotzki, R., Heber, U., Christlieb, N. and Reimers, D. (2005) HE 0437‐5439: An unbound hypervelocity main-sequence B‐type star. The Astrophysical Journal, 634, L181‐L184.

[3]   Hirsch, H.A., Heber, U., O’Toole, S.J. and Bresolin, F. (2005) US 708—An unbound hyper-velocity subluminous O star. Astronomy and Astrophysics, 444, L61‐L64.

[4]   Brown, W.R., Geller, M.J., Kenyon, S. J. and Kurtz, M.J. (2006) A successful targeted search for hypervelocity stars. The Astrophysical Journal, 640, L35‐L38.

[5]   Brown, W.R., Geller, M.J., Kenyon, S.J. and Kurtz, M.J. (2006) Hypervelocity stars. I. The spectroscopic survey. The Astrophysical Journal, 647, 303‐311.

[6]   Brown, W.R., Geller, M.J., Kenyon, S.J., Kurtz, M.J. and Bromley, B.C. (2007) Hypervelocity stars. II. The bound population. The Astrophysical Journal, 660, 311‐318.

[7]   Brown, W.R., Geller, M.J., Kenyon, S.J., Kurtz, M.J. and Bromley, B.C. (2007) Hypervelocity stars. III. The space density and ejection history of main‐sequence stars from the galactic center. The Astrophysical Journal, 671, 1708‐1716.

[8]   Heber, U., Edelmann, H., Napiwotzki, R., Altmann, M. and Scholz, R.‐D. (2008) The B‐type giant HD 271791 in the galactic halo. linking run-away stars to hyper-velocity stars. Astronomy and Astrophysics, 483, L21‐L24.

[9]   Brown, W.R., Geller, M.J. and Kenyon, S.J. (2009) MMT hypervelocity star survey. The Astrophysical Journal, 690, 1639‐1647.

[10]   Tillich, A., Przybilla, N., Scholz, R. and Heber, U. (2009) SDSS J013655.91+242546.0—An A‐type hyper-velocity star from the outskirts of the galaxy. Astronomy and Astrophysics, 507, L37‐L40.

[11]   Brown, W.R., Anderson, J., Gnedin, O.Y., Bond, H.E., Geller, M.J., Kenyon, S.J. and Livio, M., (2010) A galactic origin for HE 0437–5439, the hypervelocity star near the large magellanic cloud. The Astrophysical Journal Letters, 719, L23‐L27.

[12]   Irrgang, A., Przybilla, N., Heber, U., Fernanda Nieva, M. and Schuh, S. (2010) The nature of the hyper‐runaway candidate hip 60350. The Astrophysical Journal, 711, 138‐143.

[13]   Ghez, A.M., Salim, S., Weinberg, N.N., Lu, J.R., Do, T., Dunn, J.K., Matthews, K., Morris, M.R., Yelda, S., Becklin, E.E., Kremenek, T., Milosavljevic, M. and Naiman, J. (2008) Measuring distance and properties of the milky way’s central supermassive black hole with stellar orbits. The Astrophysical Journal, 689, 1044‐ 1062.

[14]   Gillessen, S., Eisenhauer, F., Trippe, S., Alexander, T., Genzel, R., Martins, F. and Ott, T. (2009) Monitoring stellar orbits around the massive black hole in the galactic center. The Astrophysical Journal, 692, 1075‐1109.

[15]   Hills, J.G. (1988) Hyper‐velocity and tidal stars from binaries disrupted by a massive galactic black hole. Nature, 331, 687‐689.

[16]   Yu, Q. and Tremaine, S. (2003) Ejection of hypervelocity stars by the (binary) black hole in the galactic center. The Astrophysical Journal, 599, 1129‐1138.

[17]   Perets, H.B., Hopman, C. and Alexander, T. (2007) Massive perturber‐driven interactions between stars and a massive black hole. The Astrophysical Journal, 656, 709‐720.

[18]   Burrows, A. (2000) Supernova explosions in the universe. Nature, 403, 727‐733.

[19]   Fryer, C.L. (2004) Neutron star kicks from asymmetric core collapse. The Astrophysical Journal Letters, 601, L175‐L178.

[20]   Caraveo, P.A. (1993) Associating young pulsars and supernova remnants: PSR 1610‐50 and the case for high-velocity pulsars. The Astrophysical Journal Letters, 415, L111‐L114.

[21]   Frail, D.A., Goss, W.M., and Whiteoak, J.B.Z. (1994) The radio lifetime of supernova remnants and the distribution of pulsar velocities at Birth. The Astrophysical Journal, 437, 781‐793.

[22]   Winkler, P.F. and Petre, R. (2007) Direct measurement of neutron star recoil in the oxygen-rich supernova remnant puppis a. The Astrophysical Journal, 670, 635‐642.

[23]   Kumar, S.S. (1963) The structure of stars of very low mass. The Astrophysical Journal, 137, 1121‐1125.

[24]   Hayashi, C. and Nakano, T. (1963) evolution of stars of small masses in the pre-main-sequence stages. Progress of Theoretical Physics, 30, 460‐474.

[25]   Nakajima, T., Oppenheimer, B.R., Kulkarni, S.R., Golimowski, D.A., Matthews, K. and Durrance, S.T. (1995) Discovery of a cool brown dwarf. Nature, 378, 463‐465.

[26]   Kirkpatrick, J.D. (2005) new spectral types L and T. Annual Review of Astronomy and Astrophysics, 43, 195‐245.

[27]   Lodieu, N., Hambly, N.C., Jameson, R.F., Hodgkin, S.T., Carraro, G. and Kendall, T.R. (2007) New brown dwarfs in upper Sco using UKIDSS galactic cluster survey science verification data. Monthly Notices of the Royal Astronomical Society, 374, 372‐384.

[28]   Luhman, K.L., Adame, L., D’Alessio, P., Calvet, N., Hartmann, L., Megeath, S.T. and Fazio, G.G. (2005) Discovery of a planetary-mass brown dwarf with a circumstellar disk. The Astrophysical Journal, 635, L93‐ L96.

[29]   Marsh, K.A., Kirkpatrick, J.D. and Plavchan, P. (2010) A young planetary-mass object in the oph cloud core. The Astrophysical Journal Letters, 709, L158‐L162.

[30]   Stevenson, D.J. (1999) Life‐sustaining planets in interstellar space. Nature, 400, 32.

[31]   Debes, J.H. and Sigurdsson, S. (2007) The survival rate of ejected terrestrial planets with moons. The Astrophysical Journal, 668, L167‐L170.

[32]   Bennett, D.P. and Rhie, S.H. (2002) Simulation of a space-based microlensing survey for terrestrial extrasolar planets. The Astrophysical Journal, 574, 985‐1003.

[33]   Landau, L.D. and Lifshitz, E.M. (1976) “Mechanics, third edition: vol. 1 (course of theoretical physics),” Butterworth‐Heinemann.

[34]   Iorio, L. (2009) Constraints on planet X/Nemesis from solar system’s inner dynamics. Monthly Notices of the Royal Astronomical Society, 400, 346-353.

[35]   Lee, T.D. and Yang, C.N. (1956) Question of parity conservation in weak interactions. Physical Review, 104, 254‐258.

[36]   Foot, R. (1999) Have mirror stars been observed? Physics Letters B, 452, 83‐86.

[37]   Foot, R. (1999) Have mirror planets been observed? Physics Letters B, 471, 191‐194.

[38]   Foot, R. and Silagadze, Z.K. (2001) Do mirror planets exist in our solar system? Acta Physica Polonica B, 32(7), 2271‐2278.

[39]   Wright, E.L., Eisenhardt, P.R.M., Mainzer, A., Ressler, M.E., Cutri, R.M., Jarrett, T., Kirkpatrick, J.D., Padgett, D., McMillan, R.S., Skrutskie, M., Stanford, S.A., Cohen, M., Walker, R.G., Mather, J.C., Leisawitz, D., III Gautier, T.N., McLean, I., Benford, D., Lonsdale, C.J., Blain, A., Mendez, B., Irace, W.R., Duval, V., Liu, F., Royer, D., Heinrichsen, I., Howard, J., Shannon, M., Kendall, M., Walsh, A.L., Larsen, M., Cardon, J.G., Schick, S., Schwalm, M., Abid, M., Fabinsky, B., Naes, L. and Tsai,

[40]   Price, S.D. (2009) Infrared sky surveys. Space Science Reviews, 142, 233‐321.

[41]   Beichman, C.A. (1987) The IRAS view of the galaxy and the solar system annual review of astronomy and astrophysics. Annual Review of Astronomy and Astrophysics, 25, 521‐563.

[42]   Miller‐Jones, J.C.A., Jonker, P.G., Dhawan, V., Brisken, W., Rupen, M.P., Nelemans, G. and Gallo, E. (2009) The first accurate parallax distance to a black hole. The Astrophysical Journal Letters, 706, L230‐L234.

[43]   Orosz, J.A., Kuulkers, E., van der Klis, M., McClintock, J.E., Garcia, M.R., Callanan, P.J., Bailyn, C.D., Jain, R.K. and Remillard, R.A. (2001) A black hole in the superluminal source SAX J1819.3‐2525 (V4641 Sgr). The Astrophysical Journal, 555, 489‐503.

[44]   Faherty, J.K., Burgasser, A.J., Cruz, K.L., Shara, M.M., Walter, F.M. and Gelino, C.R. (2009) The brown dwarf kinematics project I. proper motions and tangential velocities for a large sample of late-type M, L, and T dwarfs. The Astronomical Journal, 137, 1‐18.

[45]   Goldreich, P., Lithwick, Y. and Sari, R. (2004) final stages of planet formation. The Astrophysical Journal, 614, 497‐507.

 
 
Top