lunes, 10 de noviembre de 2014
Astronomers are announcing today the discovery of two unusual objects in comet-like orbits that originate in the Oort cloud but with almost no activity, giving scientists a first look at their surfaces. These results, presented today at the annual meeting of the Division of Planetary Sciences of the American Astronomical Society in Tucson, Arizona, are particularly intriguing because the surfaces are different from what astronomers expected, and they give us clues about the movement of material in the early solar system as the planets were assembled. On August 4, 2013 an apparently asteroidal object, C/2013 P2 Pan-STARRS, was discovered by the Pan STARRS1 survey telescope (PS1) on Haleakala, Maui, Hawaii. What made this object unique is its orbit – that of a comet coming from the Oort cloud, with an orbital period greater than 51 million years, yet no cometary activity was seen. The Oort cloud is a spherical halo of comet nuclei in the outer solar system that extends to about 100,000 times the Earth-sun distance, which is known as 1 astronomical unit, or 1 AU. “Objects on long-period orbits like this usually exhibit cometary tails, for example comet ISON and comet Hale Bopp, so we immediately knew this object was unusual,” explained team leader Dr. Karen Meech (Institute for Astronomy, University of Hawaii at Manoa). “I wondered if this could be the first evidence of movement of solar system building blocks from the inner solar system to the Oort cloud.” Follow-up observations in September 2013 with the 8-meter Gemini North telescope on Maunakea, Hawaii, hinted at faint, low-level light reflected off a dusty tail. This tail remained through the object’s closest approach to the sun (2.8 times the Earth-sun distance, within the outer asteroid belt) in February 2014, but the object didn’t get much brighter. When the object was observable again in the spring, the team used the Gemini North telescope to obtain a spectrum of the surface, which showed that it was very red, completely different from comet or asteroid surfaces, and more like the surface of an ultra-red Kuiper belt object. “We had never seen a naked (inactive) Oort cloud comet, but Jan Oort hypothesized their existence back in 1950 when he inferred the existence of what we now call the Oort cloud. Oort suggested that these bodies might have a layer of “volatile frosting” left over from 4.5 billion years of space radiation that disappears after their first pass through the inner solar system. Maybe we are seeing the first evidence of this,” said Dr. Olivier Hainaut of the European Southern Observatory. While the team analyzed their observations of comet C/2013 P2 Pan-STARRS, a second object was discovered. C/2014 S3 Pan-STARRS was discovered through the NASA-sponsored Near Earth Object Survey on the PS1 telescope on September 22, 2014. Like C/2013 P2 Pan-STARRS, it was on the same type of cometary orbit and also showed minimal activity. Team member Dr. Richard Wainscoat (IfA, UHM) commented, “With PS1 now exclusively involved in surveying the solar system for Near Earth Objects (NEOs), we expect to find many fascinating objects. This will help revolutionize our understanding of the early solar system.”
domingo, 9 de noviembre de 2014
Download here 360 kb https://www.dropbox.com/s/8mbe4psopvt4gws/Analysis%20of%20the%20outburts%20of%20the%20comet%20C.pdf?dl=0
viernes, 7 de noviembre de 2014
Interestingly comet could observe visual magnitude +6.5 in early January 2015, currently ICQ ephemeris put m1 = 12.4 ( 30/10/2014 ), and its visual magnitude observed is m1 = 11.0 ( S.Aguirre Mexico , last visual observation 30/10/2014 ), this -1.4 magnitudes brighter than theoretical, so which could reach maximum brightness for early January 2015 m1 = + 6.5, in the limit of visibility with the naked eye, will be observable in the hemisphere in mid-December 2014. My personal preliminary analysis of the light curve of this comet indicates a high rate of increase in brightness and a high slope in the brightness law (S. Yoshida n = 6.0) this indicates an activity index alo gas and dust nuclear level, in fact the cCD images show strong central condensation typical of bright comets, my personal opinion is that we have a good comet for December and January 2015.
martes, 4 de noviembre de 2014
sábado, 1 de noviembre de 2014
News results of comet C/2014 Q3 BORISOV , i calculated the gas to dust mass ratio , basing in data log (QH2O) and Afro parameter , applied the formulae below indicate , the comet is relatively gas rich , the last data of Afro parameter indicate poor activity of dust 80-90 cms. , and my last data of log (OH) = 27.00 mol s-1 , 30 kg/sec. , d log(QH2O) =+12 kg/sec Others preliminar results , the flow velocity of water gas is 0.75 km s-1 , and gas temperature ~ 60 K ( Based in model D.Pierce et al. 2010 ) The increased brightness in the visual indicating increased activity in the Swan bands and cometary molecules of carbon , the last visual observation m1=+10.4 , in the outburst the comet is m1=+11.2 More data , the log Q ( C2 ) ~ 10e24.00 mol s-1 , comparison water rate production of comet 1P/HALLEY , the comet C/2014 Q3 BORISOV , at heliocentric distance r=1.5 au , 10e29 mol s-1 ( Halley ) , 10e27.00 mol s-1 ( Borisov ). To mass of comet C/2014 Q3 BORISOV is calculate by relation of Whipple ( 1976 ) , log M (g) =19.39-0.6 * (m1-5log(d) ) , the preliminar results indicate mass 2.5x10e(17) grs. , for comparison Halley's comet is 22.5x10e(19) grs. The slope of the C2 production rate is simply : log C2 = -n log r and similarly for the water rate production . Dust Production J0 = 2.5 n log r +C for the comet C/2014 Q3 BORISOV this equation is defined for J0 = 23.8 log r + C , C is variable , the author is defined by C = 0.46 log r C2 production , log Q (C2+) = -n log r = 23.8 log r and equal for the water production . The table below indicate the correlation between H2O vs C2 in comets and comparison for comet C/2014 Q3 BORISOV the results indicate the poor activity in C2 , H2O principals gases for sublimation from the nucleus
martes, 28 de octubre de 2014
Hi all, I just made a small analysis of the visual light curve borisov comet C / 2014 Q3, few visual observations of the comet, but there are two conclusions: 1 Date of outburts, October 19 2 increase or variation in brightness of the 3 visual magnitudes The main hypothesis in this type of glitter explosions as fast, from one day to another, is a sudden outburst of gas and dust from the same core, constant brightness trend these days would indicate that the comet keeps this activity because a significant level blast volatile ices and dust in the same nucleus, green images confirm this fact.