El cometa C/2014 Q2 Lovejoy

Actualizado al 12/01/2015

Este cometa, cuya predicción lo ponía como máximo en la magnitud 8,6 (apenas visible desde cielos oscuros con binoculares), pasó a fines de diciembre la magnitud suficiente como para poder pronosticar, que llegaría a la mag. 4. Hoy, ya supero la mag 3,8, y es visible débilmente a simple vista desde cielos oscuros, Con binoculares presentas una débil cola.

El Lovejoy fotografiado por Andres Chapman.

Hoy 12/1. el cometa esta en mag 3,8..... y tal vez siga subiendo....

Adicionalmente, cruzará una zona del cielo fácil de hallar, y en un horario interesante, no demasiado tarde.

Fue descubierto el 17 de agosto de 2014 por el australiano T. Lovejoy, en magnitud 14,8. El perihelio lo alcanzará el 30 de enero de 2015.

Estará en diciembre en la constelación de Pupis, del 18/12 al 27/12 en Columba, del 28/12 al 2/1/15 en Lepus, del 3/1 al 9/1 en Eridanus, del 10/1 al 16/1 en Taurus y del 17/1 al 24/1 en Aries.

Fue publicada en Sky and Tel. Tomadas por Gerald Rhemann en Austria, trabando remotamente con un astrógrafo de 30 cm f/d 3,6 en Namibia. Son de fines de diciembre, cuando no estaba tan brillante.....

En todo este periodo esta muy cerca de Orion. Entre el 16 y 19 de enero pasa muy cerca de las Pleyades,

Desde el hemisferio sur tendrá excelentes condiciones de observación hasta fines de enero de 2015. Tal vez supere la mag. 4. El máximo de brillo lo alcanzará alrededor del 10 de enero de 2015.

El cometa el 11/1.... foto de Gerald Rhemann

Según datos suministrados por Fernando Giménez Minonne, de observaciones de De Raúl Salvo y Sergio Babino lo ponen en mag, 6,5. (17/12/2014). No esperes ver una cola demasiado larga, ya que en todo el periodo se ve en un angulo de 45 grados aproximadamente. El 20/12/2014, alcanzó la mag. 5,6. El 27/12 tuvo mag. 5 aproximadamente. El 12/1 esta en 3,8 y tal vez siga subiendo.

La curva de luz que sigue fue suministrada por Seiichi Yoshida. (al 12/1/15).

La línea roja es el brillo predicho. Los puntos negros, observaciones. Nota como hasta noviembre de 2014 se mantiene debajo de la predicción. Ahora tiene un pico, es posible una pequeña explosión. Como se ve claramente en la curva, sigue subiendo, pero se esta alejando de la Tierra, asi que es razonable que comience a bajar en cualquier momento.

Los mapas generales

Aqui podras ver aproximandamente por donde pasara el cometa. Son mapas del sitio de S. Yoshida.

Un mapa de mejor calidad del Sky and Telescope

Imágenes

Predicción exacta

La siguiente predicción es del sitio Horizon de la NASA, y tiene la magnitud vieja, por lo que debes considerar que el cometa está al menos 4 magnitudes (40 veces) mas brillante aproximadamente que lo que predice (la magnitud total, la del núcleo no se modifica).
Las coordenadas sí son exactas, geocentricas. Con esto podrás hallarlo con precisión.

*******************************************************************************
Ephemeris / WWW_USER Wed Dec 17 07:11:27 2014 Pasadena, USA      / Horizons    
*******************************************************************************
Target body name: Lovejoy (C/2014 Q2)             {source: JPL#14}
Center body name: Earth (399)                     {source: DE-0431LE-0431}
Center-site name: GEOCENTRIC
*******************************************************************************
Start time      : A.D. 2014-Dec-10 00:00:00.0000 UT      
Stop  time      : A.D. 2015-Feb-28 00:00:00.0000 UT      
Step-size       : 1440 minutes
*******************************************************************************
Target pole/equ : No model available
Target radii    : (unavailable)                                                
Center geodetic : 0.00000000,0.00000000,0.0000000 {E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: 0.00000000,0.00000000,0.0000000 {E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : High-precision EOP model        {East-longitude +}
Center radii    : 6378.1 x 6378.1 x 6356.8 km     {Equator, meridian, pole}    
Target primary  : Sun
Vis. interferer : MOON (R_eq= 1737.400) km        {source: DE-0431LE-0431}
Rel. light bend : Sun, EARTH                      {source: DE-0431LE-0431}
Rel. lght bnd GM: 1.3271E+11, 3.9860E+05 km^3/s^2                              
Small-body perts: Yes                             {source: SB431-BIG16}
Atmos refraction: NO (AIRLESS)
RA format       : HMS
Time format     : CAL 
EOP file        : eop.141216.p150309                                           
EOP coverage    : DATA-BASED 1962-JAN-20 TO 2014-DEC-16. PREDICTS-> 2015-MAR-08
Units conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s 
Table cut-offs 1: Elevation (-90.0deg=NO ),Airmass (>38.000=NO), Daylight (NO )
Table cut-offs 2: Solar Elongation (  0.0,180.0=NO ),Local Hour Angle( 0.0=NO )
*******************************************************************************
Initial FK5/J2000.0 heliocentric ecliptic osculating elements (au, days, deg.):
  EPOCH=  2456948.5 != 2014-Oct-18.0000000 (CT)   RMSW= n.a.                   
   EC= .997726325391938    QR= 1.290377419757231   TP= 2457052.5726738246      
   OM= 94.97595375294146   W= 12.39528778787404    IN= 80.30286418086281       
Comet physical (GM= km^3/s^2; RAD= km):                                        
   GM= n.a.                RAD= n.a.                                           
   M1=  9.       M2=  12.      k1=  10.    k2=  5.      PHCOF=  .030           
*************************************************************************************************
 Date__(UT)__HR:MN     R.A._(ICRF/J2000.0)_DEC  T-mag  N-mag   1-way_LT    S-O-T /r    S-T-O Cnst
*************************************************************************************************
$$SOE
 2014-Dec-10 00:00     07 10 15.46 -42 23 18.1  10.42  13.70   7.124011 108.7441 /L  38.4800  Pup
 2014-Dec-11 00:00     07 06 24.34 -42 02 47.5  10.35  13.63   6.953323 109.7038 /L  38.4324  Pup
 2014-Dec-12 00:00     07 02 22.18 -41 39 58.8  10.27  13.57   6.784030 110.6858 /L  38.3624  Pup
 2014-Dec-13 00:00     06 58 08.75 -41 14 39.7  10.20  13.50   6.616313 111.6903 /L  38.2685  Pup
 2014-Dec-14 00:00     06 53 43.85 -40 46 36.5  10.12  13.43   6.450371 112.7173 /L  38.1497  Pup
 2014-Dec-15 00:00     06 49 07.33 -40 15 34.9  10.04  13.36   6.286420 113.7667 /L  38.0049  Pup
 2014-Dec-16 00:00     06 44 19.07 -39 41 19.3   9.97  13.29   6.124695 114.8380 /L  37.8331  Pup
 2014-Dec-17 00:00     06 39 19.01 -39 03 33.1   9.89  13.21   5.965451 115.9304 /L  37.6336  Pup
 2014-Dec-18 00:00     06 34 07.18 -38 21 58.7   9.81  13.14   5.808966 117.0425 /L  37.4060  Col
 2014-Dec-19 00:00     06 28 43.65 -37 36 17.6   9.73  13.06   5.655542 118.1723 /L  37.1500  Col
 2014-Dec-20 00:00     06 23 08.57 -36 46 10.6   9.66  12.99   5.505505 119.3172 /L  36.8662  Col
 2014-Dec-21 00:00     06 17 22.19 -35 51 17.5   9.58  12.91   5.359210 120.4735 /L  36.5555  Col
 2014-Dec-22 00:00     06 11 24.87 -34 51 18.4   9.50  12.83   5.217038 121.6363 /L  36.2198  Col
 2014-Dec-23 00:00     06 05 17.02 -33 45 53.0   9.43  12.75   5.079399 122.7994 /L  35.8618  Col
 2014-Dec-24 00:00     05 58 59.21 -32 34 41.7   9.35  12.68   4.946732 123.9551 /T  35.4856  Col
 2014-Dec-25 00:00     05 52 32.07 -31 17 25.9   9.28  12.60   4.819504 125.0937 /T  35.0965  Col
 2014-Dec-26 00:00     05 45 56.34 -29 53 49.0   9.20  12.52   4.698210 126.2032 /T  34.7014  Col
 2014-Dec-27 00:00     05 39 12.86 -28 23 36.9   9.13  12.45   4.583369 127.2696 /T  34.3092  Col
 2014-Dec-28 00:00     05 32 22.57 -26 46 39.2   9.06  12.38   4.475521 128.2763 /T  33.9304  Lep
 2014-Dec-29 00:00     05 25 26.46 -25 02 49.8   9.00  12.31   4.375222 129.2042 /T  33.5777  Lep
 2014-Dec-30 00:00     05 18 25.62 -23 12 08.7   8.93  12.24   4.283035 130.0325 /T  33.2654  Lep
 2014-Dec-31 00:00     05 11 21.19 -21 14 42.1   8.88  12.19   4.199526 130.7383 /T  33.0091  Lep
 2015-Jan-01 00:00     05 04 14.33 -19 10 44.2   8.82  12.13   4.125243 131.2983 /T  32.8252  Lep
 2015-Jan-02 00:00     04 57 06.25 -17 00 37.5   8.77  12.09   4.060714 131.6900 /T  32.7298  Lep
 2015-Jan-03 00:00     04 49 58.17 -14 44 53.0   8.73  12.05   4.006422 131.8926 /T  32.7376  Eri
 2015-Jan-04 00:00     04 42 51.29 -12 24 10.7   8.69  12.03   3.962796 131.8894 /T  32.8607  Eri
 2015-Jan-05 00:00     04 35 46.80 -09 59 18.6   8.66  12.01   3.930192 131.6692 /T  33.1072  Eri
 2015-Jan-06 00:00     04 28 45.83 -07 31 11.6   8.63  12.00   3.908881 131.2272 /T  33.4801  Eri
 2015-Jan-07 00:00     04 21 49.48 -05 00 50.4   8.61  12.00   3.899036 130.5662 /T  33.9772  Eri
 2015-Jan-08 00:00     04 14 58.77 -02 29 18.5   8.60  12.02   3.900728 129.6960 /T  34.5906  Eri
 2015-Jan-09 00:00     04 08 14.64 +00 02 19.2   8.60  12.04   3.913914 128.6329 /T  35.3078  Eri
 2015-Jan-10 00:00     04 01 37.94 +02 32 59.4   8.60  12.07   3.938449 127.3983 /T  36.1125  Tau
 2015-Jan-11 00:00     03 55 09.43 +05 01 42.3   8.61  12.11   3.974082 126.0168 /T  36.9858  Tau
 2015-Jan-12 00:00     03 48 49.78 +07 27 34.0   8.62  12.16   4.020473 124.5146 /T  37.9078  Tau
 2015-Jan-13 00:00     03 42 39.54 +09 49 47.2   8.64  12.21   4.077203 122.9180 /T  38.8588  Tau
 2015-Jan-14 00:00     03 36 39.18 +12 07 42.9   8.67  12.27   4.143787 121.2522 /T  39.8202  Tau
 2015-Jan-15 00:00     03 30 49.09 +14 20 49.9   8.70  12.34   4.219695 119.5401 /T  40.7752  Tau
 2015-Jan-16 00:00     03 25 09.53 +16 28 45.7   8.74  12.40   4.304363 117.8020 /T  41.7093  Tau
 2015-Jan-17 00:00     03 19 40.71 +18 31 15.3   8.77  12.47   4.397207 116.0552 /T  42.6106  Ari
 2015-Jan-18 00:00     03 14 22.75 +20 28 10.5   8.82  12.54   4.497638 114.3142 /T  43.4694  Ari
 2015-Jan-19 00:00     03 09 15.71 +22 19 29.3   8.86  12.62   4.605073 112.5908 /T  44.2784  Ari
 2015-Jan-20 00:00     03 04 19.55 +24 05 14.7   8.91  12.69   4.718941 110.8940 /T  45.0326  Ari
 2015-Jan-21 00:00     02 59 34.22 +25 45 33.7   8.96  12.76   4.838689 109.2309 /T  45.7284  Ari
 2015-Jan-22 00:00     02 54 59.59 +27 20 36.4   9.01  12.83   4.963791 107.6064 /T  46.3640  Ari
 2015-Jan-23 00:00     02 50 35.48 +28 50 35.1   9.06  12.90   5.093746 106.0242 /T  46.9387  Ari
 2015-Jan-24 00:00     02 46 21.69 +30 15 43.9   9.11  12.97   5.228084 104.4864 /T  47.4530  Ari
 2015-Jan-25 00:00     02 42 17.98 +31 36 17.8   9.16  13.04   5.366368 102.9942 /T  47.9080  Tri
 2015-Jan-26 00:00     02 38 24.09 +32 52 32.0   9.22  13.11   5.508188 101.5479 /T  48.3053  Tri
 2015-Jan-27 00:00     02 34 39.74 +34 04 42.1   9.27  13.18   5.653167 100.1473 /T  48.6470  Tri
 2015-Jan-28 00:00     02 31 04.63 +35 13 03.4   9.33  13.24   5.800955  98.7917 /T  48.9357  Tri
 2015-Jan-29 00:00     02 27 38.47 +36 17 50.8   9.38  13.30   5.951231  97.4800 /T  49.1739  Tri
 2015-Jan-30 00:00     02 24 20.96 +37 19 18.7   9.44  13.36   6.103697  96.2108 /T  49.3642  And
 2015-Jan-31 00:00     02 21 11.79 +38 17 40.7   9.49  13.42   6.258081  94.9829 /T  49.5094  And
 2015-Feb-01 00:00     02 18 10.66 +39 13 09.9   9.54  13.48   6.414130  93.7947 /T  49.6122  And
 2015-Feb-02 00:00     02 15 17.29 +40 05 58.4   9.60  13.53   6.571614  92.6446 /T  49.6752  And
 2015-Feb-03 00:00     02 12 31.37 +40 56 17.7   9.65  13.59   6.730318  91.5310 /T  49.7011  And
 2015-Feb-04 00:00     02 09 52.64 +41 44 18.7   9.71  13.64   6.890044  90.4525 /T  49.6923  And
 2015-Feb-05 00:00     02 07 20.81 +42 30 11.2   9.76  13.69   7.050612  89.4075 /T  49.6513  And
 2015-Feb-06 00:00     02 04 55.62 +43 14 04.6   9.81  13.74   7.211852  88.3945 /T  49.5802  And
 2015-Feb-07 00:00     02 02 36.82 +43 56 07.7   9.86  13.79   7.373608  87.4123 /T  49.4813  And
 2015-Feb-08 00:00     02 00 24.16 +44 36 28.4   9.92  13.83   7.535735  86.4594 /T  49.3567  And
 2015-Feb-09 00:00     01 58 17.40 +45 15 14.2   9.97  13.88   7.698098  85.5347 /T  49.2083  And
 2015-Feb-10 00:00     01 56 16.32 +45 52 32.0  10.02  13.92   7.860573  84.6369 /T  49.0380  And
 2015-Feb-11 00:00     01 54 20.70 +46 28 28.3  10.07  13.96   8.023042  83.7651 /T  48.8475  And
 2015-Feb-12 00:00     01 52 30.32 +47 03 09.1  10.12  14.00   8.185396  82.9181 /T  48.6384  And
 2015-Feb-13 00:00     01 50 44.99 +47 36 39.8  10.17  14.04   8.347533  82.0951 /T  48.4123  And
 2015-Feb-14 00:00     01 49 04.52 +48 09 05.7  10.22  14.08   8.509357  81.2951 /T  48.1708  Per
 2015-Feb-15 00:00     01 47 28.72 +48 40 31.4  10.27  14.12   8.670778  80.5173 /T  47.9151  And
 2015-Feb-16 00:00     01 45 57.42 +49 11 01.4  10.32  14.16   8.831713  79.7609 /T  47.6465  And
 2015-Feb-17 00:00     01 44 30.44 +49 40 39.8  10.37  14.19   8.992079  79.0253 /T  47.3663  And
 2015-Feb-18 00:00     01 43 07.61 +50 09 30.4  10.42  14.23   9.151804  78.3099 /T  47.0757  And
 2015-Feb-19 00:00     01 41 48.79 +50 37 36.8  10.47  14.26   9.310815  77.6139 /T  46.7756  And
 2015-Feb-20 00:00     01 40 33.80 +51 05 02.4  10.52  14.29   9.469046  76.9368 /T  46.4673  Per
 2015-Feb-21 00:00     01 39 22.50 +51 31 50.0  10.56  14.32   9.626435  76.2782 /T  46.1516  Per
 2015-Feb-22 00:00     01 38 14.74 +51 58 02.6  10.61  14.36   9.782925  75.6374 /T  45.8295  Per
 2015-Feb-23 00:00     01 37 10.39 +52 23 42.8  10.66  14.39   9.938462  75.0141 /T  45.5018  Per
 2015-Feb-24 00:00     01 36 09.29 +52 48 53.0  10.70  14.42  10.092998  74.4078 /T  45.1694  Per
 2015-Feb-25 00:00     01 35 11.34 +53 13 35.4  10.75  14.45  10.246486  73.8181 /T  44.8330  Per
 2015-Feb-26 00:00     01 34 16.40 +53 37 52.1  10.80  14.48  10.398887  73.2446 /T  44.4934  Per
 2015-Feb-27 00:00     01 33 24.36 +54 01 45.1  10.84  14.50  10.550161  72.6869 /T  44.1513  Per
 2015-Feb-28 00:00     01 32 35.12 +54 25 16.1  10.89  14.53  10.700273  72.1448 /T  43.8073  Per
$$EOE
*************************************************************************************************
Column meaning:
 
TIME

  Prior to 1962, times are UT1. Dates thereafter are UTC. Any 'b' symbol in
the 1st-column denotes a B.C. date. First-column blank (" ") denotes an A.D.
date. Calendar dates prior to 1582-Oct-15 are in the Julian calendar system.
Later calendar dates are in the Gregorian system.

  Time tags refer to the same instant throughout the universe, regardless of
where the observer is located.

  The dynamical Coordinate Time scale is used internally. It is equivalent to
the current IAU definition of "TDB". Conversion between CT and the selected
non-uniform UT output scale has not been determined for UTC times after the
next July or January 1st.  The last known leap-second is used over any future
interval.

  NOTE: "n.a." in output means quantity "not available" at the print-time.
 
 R.A._(ICRF/J2000.0)_DEC =
   J2000.0 astrometric right ascension and declination of target center.
Adjusted for light-time. Units: HMS (HH MM SS.ff) and DMS (DD MM SS.f)
 
 T-mag N-mag =
   Comet's approximate apparent visual total magnitude ("T-mag") and nuclear
magnitude ("N-mag") by following standard IAU definitions:
    T-mag =  M1 + 5*log10(delta) + k1*log10(r)
    N-mag =  M2 + 5*log10(delta) + k2*log10(r) + phcof*beta
   Units: MAGNITUDES
 
 1-way_LT =
   1-way down-leg light-time from target center to observer. The elapsed time
since light (observed at print-time) would have left or reflected off a point
at the center of the target. Units: MINUTES
 
 S-O-T /r =
    Sun-Observer-Target angle; target's apparent solar elongation seen from
observer location at print-time. If negative, the target center is behind
the Sun. Angular units: DEGREES.

    The '/r' column is a Sun-relative code, output for observing sites
with defined rotation models only.

         /T indicates target trails Sun (evening sky)
         /L indicates target leads Sun  (morning sky)

    NOTE: The S-O-T solar elongation angle is the total separation in any
direction. It does not indicate the angle of Sun leading or trailing.
 
 S-T-O =
   "S-T-O" is the Sun->Target->Observer angle; the interior vertex angle at
target center formed by a vector to the apparent center of the Sun at
reflection time on the target and the apparent vector to the observer at
print-time. Slightly different from true PHASE ANGLE (requestable separately)
at the few arcsecond level in that it includes stellar aberration on the
down-leg from target to observer.  Units: DEGREES
 
 Cnst =
   Constellation ID; the 3-letter abbreviation for the name of the
constellation containing the target center's astrometric position,
as defined by IAU (1930) boundary delineation.  See documentation
for list of abbreviations.


 Computations by ...
     Solar System Dynamics Group, Horizons On-Line Ephemeris System
     4800 Oak Grove Drive, Jet Propulsion Laboratory
     Pasadena, CA  91109   USA
     Information: http://ssd.jpl.nasa.gov/
     Connect    : telnet://ssd.jpl.nasa.gov:6775  (via browser)
                  telnet ssd.jpl.nasa.gov 6775    (via command-line)
     Author     : Jon.Giorgini@jpl.nasa.gov