martes, 28 de mayo de 2013

Warm Spitzer Characterization of Comet C/2012 S1 (ISON) : Spitzer Proposal ID #9026

We propose Warm Spitzer photometric imaging DDT observations of Comet ISON, as part of a worldwide observing campaign led by NASA of the comet. Warm Spitzer's 3 and 4 um near-IR passbands will provide unique scattering and emissivity information for the comet's nucleus and dust, and allow us to detect CO_2 gas emission from the comet. Spitzer holds a unique place in the solar system to observe the comet, right before it enters the region of rapid water ice sublimation after spending millions of years in the deep freeze of the Oort Cloud. It is likely the comet will undergo a rapid outburst soon after the time of the proposed observations in the week of June 7 - 14, 2013, and understanding its baseline behavior is critical to understanding the evolution of its activity, as is Spitzer's unique ability to detect CO_2 sublimation and outgassing activity from ISON. As for our previous Spitzer observations of comets Tempel 1 and Hartley 2, we will bootstrap from HST DDT imaging lightcurve and spectroscopic measurements taken over in April - May 2013. The combination of the two datasets will place strong constraints on the comet's coma morphology, and thus its pattern of outgassing jets and the rotation state of the nucleus, and the amount and kind of dust and gas emitted by the comet. Authors : L.Carey et al.

lunes, 20 de mayo de 2013

COMPARISON GAS-TO-DUST RATIO ISON vs 18 COMETS

I have measured and compared the gas-to-dust ratio ( GDR ) , the GDR of the comet C/2012 S1 ISON with 18 comets of half , the dust outflow velocity is assumed to be proportional to the heliocentric distance to the -0.5 power , the GDR for the 18 comets is not constant , the ISON's comet show the water outgassing rate of 1 kgs/sec based in SWIFT ( NASA ) and the 850 kgrs/sec of dust rate in r=4.9 au. , the next equation ( Weiller et al. 2003 ) log M gas / log Mdust = log Q ( OH ) / Afp , his solution to the ISON's comet is 0.0011 , for the 18 comets increasing gas production may be quantified by setting the dust production proportional to the gas production raised to the 0.55 (+-0.17) power interpret this increase as showing that outgassing is primarily throught a porous mantle , trough which gas can flow relatively easily but in which most of the dust grains are trapped for 18 comets , ISON's comet sublimate large amount of dust and the gas are trapped .

miércoles, 15 de mayo de 2013

NASA Comet ISON Observing Campaign , CIOC

J.P.Navarro Pina is admitted for new member of CIOC_NASA facebook group , this group (NASA_Comet ISON Observing Campaign, CIOC) provides outreach and its membership consists of comet observers, imagers, scientists, educators, etc . The administrators of NASA_CIOC : Elizabeth Warner (University of Maryland) and Padma Yanamandra-Fisher (Space Science Institute), web page : http://sungrazer.nrl.navy.mil/index.php?p=ison

viernes, 10 de mayo de 2013

COMPARISON DUST RATE PRODUCTION COMET HALE-BOPP vs COMET ISON

The preliminar analysis of comparison of dust rate production's of comets C/1995 O1 HALE-BOPP , shows the comet C/2012 S1 ISON sublimates a factor of 6 times less than the comet C/1995 O1 HALE-BOPP to heliocentric distance r = 5.0 au , the hale-bopp's comet sublimate's , Q(dust)~ 5.000 kg/sec. in r=5.0 au , the ISON's comet based in observations of SWIFT ( NASA ) sublimate the Jan. 30 UVOT reveal that ISON was shedding about 112,000 pounds (51,000 kg) of dust every minute , or 850 kg/sec. ,in R=4.9 au , the next graphic adapted the work of the M.Weiller et al.( 2.003 ) ''The dust activity of comet C/1995 O1 HALE-BOPP between 3 au and 13 au from the sun'' shows this information .

jueves, 2 de mayo de 2013

NEW PAPER : ''ON PHASE DEPENDENCIES OF COMETARY LIGHT CURVES''

Published new work titled : ON PHASE DEPENDENCIES OF COMETARY LIGHT CURVES , by author J.P.Navarro Pina ( Subscribed to the prestigious revist ASTRONOMY AND ASTROPHYSICS and EDPS Sciences Journal List account , and the CORNELL UNIVERSITY LIBRARY , arxiv.org ) , Published in WEB PAGE of facebook INTERNATIONAL COMET GROUP . Download here : https://www.dropbox.com/s/tasayuav1p6x1uu/ON%20PHASE%20DEPENDENCIES%20OF%20COMETARY%20LIGHT%20CURVES.pdf