viernes, 4 de julio de 2014

NEW CCD CURVE OF COMET C/2014 E2 JACQUES

CCD LIGHT CURVE REDUCED MAGNITUD vs LOG 10 HELIOCENTRIC DISTANCE AU Based in 854 ccd's observations from MPC DATABASE FROM IAU CCD LIGHT CURVE REDUCED MAGNITUDE vs HELIOCENTRIC DISTANCE

miércoles, 25 de junio de 2014

SOLAR AND HELIOSPHERIC OBSERVATORY/SOLAR WIND ANISOTROPIES OBSERVATIONS OF MODERATELY BRIGHT COMETS: 1999–2014

The author J.P.Navarro Pina investigated the recient observations of SOHO / SWAN of Observations of hydrogen Lyman-α (Ly-α) at 1215.7 Å in comets and their interpretation are important. Atomic hydrogen is the most abundant species in the atmosphere (or coma) of a comet being produced in a photodissociation chain originating with water molecules and including intermediate OH radicals. Water is the most abundant volatile species in a comet’s nucleus, and water sublimation controls the abundance and activity of the coma when comets are within 3 AU from the Sun. Measurements of the abundance and distribution of hydrogen in the coma, when appropriately modeled, can provide a reliable measure of the water production rate and its variation in time in comets. Virtually all compositional information is compared to water, making water the most important species for obtaining accurate production rates. Variations in production rate with time generally, and with heliocentric distance in particular can provide information about the composition and structure of the nucleus. nucleus. Solar Wind Anisotropies (SWAN), the all-sky hydrogen Ly-α camera, has been operating on the Solar and Heliospheric Observatory (SOHO) spacecraft since its launch in 1995. The SWAN instrument was designed to observe the entire sky in H Ly-α in order to obtain a global view of the variable interaction of the solar wind with the neutral interstellar hydrogen streaming through the solar system. From its viewpoint at the L1 Lagrange point between the Earth and Sun it obtains an unparallel view of the Sun, its large extended corona, and the entire sky. For a more detailed description of SWAN, see Bertaux et al.

sábado, 17 de mayo de 2014

Update Catalog of Nuclear Magnitudes of Periodic Comets

A catalog of a sample of 225 periodic comets is presented with our ``best estimates'' of their absolute nuclear magnitudes HN = V(1,0,0). It includes either Jupiter family (JF) comets (defined as those with Tisserand constants T > 2 and perihelion distance inside Jupiter q < QJ), Halley-type comets (T < 2) and a few Centaurs comets (T > 2 and perihelion distance outside Jupiter q >QJ). DOWNLOAD HERE ( 560 KB ): https://www.dropbox.com/s/ajsuz5w263oxzr1/new%20Catalog%20of%20Nuclear%20Magnitudes.pdf

viernes, 2 de mayo de 2014

LIGHT CCD CURVE OF COMET C/2012 K1 PANSTARRS FROM MPC DATABASE IAU BASED IN 2.836 OBSERVATIONS ...

I just finished my last differential analysis curve ccd light based in more of 2.800 ccd's observations from MPC IAU , the light curve reduced the comet mred-log r sample 3 laws of different brightness due to the change of the strong component of the predominant chemical volatile comet, CH4 -> CO-> H2O in the heliocentric range 2.5 H2O, my analysis does not show favorable data regarding the brightness of the comet and I have doubts that it displays bright, my statistical analysis shows a 80% chance of not exceeding magnitude m1 = +8, and 20% to m1 = +6, ICQ gives m1 = 8.5 theoretical and actual visual observations really it 9.5-10.5

miércoles, 19 de febrero de 2014

The comet-asteroid P/2013 P5 by HST

P/2013 P5 PANSTARRS was discovered in Aug. 2013, displaying a cometary tail, but with orbital elements typical for a member of the inner asteroid Main Belt. We monitored the object from 2013 Aug. 30 until Oct. 05 using the CFHT, NTT, CA 1.23m, Perkins 1.8m (Lowell), and the 0.6m TRAPPIST telescopes. We measured its nuclear radius to be r < 0.25-0.29km, and its colours g-r = 0.58+/-0.05 and r-i = 0.23+/-0.06, typical for an S-class asteroid. We failed to detect any rotational light curve, with an amplitude < 0.05mag and a double-peaked rotation period < 20h. A detailed Finson-Probstein analysis of deep NTT and CFHT images indicated that the object was active since at least late January 2013 until the time of the latest observations in 2013 September, with at least two peaks of activity around 2013 June 14+/-10d and 2013 July 22+/-3d. The changes of activity level and the activity peaks were extremely sharp and short, shorter than the temporal resolution of our observations (about 1d). The dust distribution was similar during these two events, with dust grains covering at least the 1-1000{\mu}m range. The total mass ejected in grains <1mm was estimated to be 3.0 10$^6$kg and 2.6 10$^7$kg around the two activity peaks. Rotational disruption cannot be ruled out as the cause of the dust ejection. We also propose that the components of a contact binary might gently rub and produce the observed emission. Volatile sublimation might also explain what appears as cometary activity over a period of 8 months. However, while Main Belt comets best explained by ice sublimation are found in the outskirts of the Main Belt, where water ice is believed to be able to survive buried in moderately large objects for the age of the solar system deeply, the presence of volatiles in an object smaller than 300m in radius would be very surprising in the inner asteroid belt. More info : http://adsabs.harvard.edu/abs/2014arXiv1401.5740H