Jupiter Trojan Lightcurve Project

 

Joshua Emery of the University of Tennessee needs lightcurves on Jupiter Trojans:

Along with several colleagues, I have a program to observe several Trojans with the Spitzer Space Telescope.  None of the objects on our target list has very good light curve data, and many of them have no info whatsoever.

Rotational data on these objects would really make our analysis of the Spitzer data more robust, especially if the light curve observations are close in time to the Spitzer observations, and I was wondering if you could help us let people know that we would appreciate such observations.

Unfortunately, Spitzer only announces its schedule a few weeks in advance, so right now we don't know exactly when our targets will be observed.  But since most of the targets don't have any light curve info, anytime anyone can observe would help.  I could send a list of dates when each object is observable with Spitzer, if it would be helpful.

What I want kind of depends on what I can get.  The following list is arranged from "really need" to "would be terrific if possible."

  1. Amplitude - if I get nothing else, this allows me to put a realistic estimate on my albedo estimate from thermal observations (since I won't have simultaneous visible, unless . . .

  2. Period - necessary to reasonably constrain thermal inertia of the surface.

  3. Calibrated brightness - H magnitudes of some of these guys are not very good, probably because they haven't had lightcurve and phase effects removed.

  4. Close-in-time light curve - A flux calibrated light curve within a few rotations of the Spitzer observations would be heaven.  Knowing the rotational phase of of the Spitzer observations would let me get a very good size and albedo (and would tighten estimates of thermal inertia, though a pole position is needed to do this well.

0.01 to 0.03 mag precision would be just fine, and I would very much enjoy having the data sent to me.

I very much encourage anyone who collects data to publish it as soon as they can.   Please don't have them wait for me.  That gives everyone the chance to do as much as they can with the data.


    

Upcoming Jupiter Trojans

 
Mag1 and Mag2 are the V mags on the first and last dates of the search period
Declination and Date are for brightest mag in the search period
Positions are geocentric, 00:00 UT
                                                          
     #  Name                      Mag1    Mag2   Dec      Date
-----------------------------------------------------------------
    617 Patroclus                15.47   15.25   -27   2009/05/21
    884 Priamus                  15.64   15.37   -31   2009/05/21
   1172 Aneas                    15.33   15.07   -18   2009/05/21
   1173 Anchises                 15.94   15.88   -25   2009/05/11
   1867 Deiphobus                15.74   15.51   -40   2009/05/21
   2241 Alcathous                15.70   15.43   -29   2009/05/21
   2357 Phereclos                16.20   15.96   -20   2009/05/21
   2674 Pandarus                 16.22   15.98   -21   2009/05/21
   2893 Peiroos                  16.06   15.92   -05   2009/05/21
   3317 Paris                    15.27   15.07   +05   2009/05/21
   3451 Mentor                   15.32   15.13   +06   2009/05/21
   7352 1994 CO                  15.91   15.71   -11   2009/05/21

*****************************************************************


617 Patroclus     H: 8.19   Min: 15.25   Date: 2009/05/21
-------------------------------------------------------------------------
   DATE       RA(2000)   DC(2000)    E.D.     S.D.     Mag     PA      E
-------------------------------------------------------------------------
2009/05/01    15 51.25   -26 43.9    4.470    5.419   15.47     3.9   158
2009/05/06    15 48.41   -26 48.2    4.440    5.414   15.40     3.1   163
2009/05/11    15 45.43   -26 51.5    4.417    5.409   15.33     2.2   168
2009/05/16    15 42.37   -26 53.7    4.402    5.404   15.27     1.5   172
2009/05/21    15 39.27   -26 54.9    4.394    5.399   15.25     1.4   173
*************************************************************************

884 Priamus     H: 8.81   Min: 15.37   Date: 2009/05/21
-------------------------------------------------------------------------
   DATE       RA(2000)   DC(2000)    E.D.     S.D.     Mag     PA      E 
-------------------------------------------------------------------------
2009/05/01    17 52.93   -30 40.9    3.818    4.552   15.64     9.5   132
2009/05/06    17 51.72   -30 42.5    3.763    4.551   15.57     8.7   137
2009/05/11    17 50.13   -30 43.5    3.712    4.549   15.51     7.9   142
2009/05/16    17 48.18   -30 43.7    3.667    4.548   15.44     7.0   147
2009/05/21    17 45.90   -30 42.9    3.627    4.547   15.37     6.0   152
*************************************************************************

1172 Aneas     H: 8.33   Min: 15.07   Date: 2009/05/21
-------------------------------------------------------------------------
   DATE       RA(2000)   DC(2000)    E.D.     S.D.     Mag     PA      E 
-------------------------------------------------------------------------
2009/05/01    17 54.27   -19 10.0    4.009    4.741   15.33     9.1   132
2009/05/06    17 53.10   -18 56.2    3.951    4.738   15.27     8.4   137
2009/05/11    17 51.59   -18 42.2    3.899    4.736   15.20     7.5   142
2009/05/16    17 49.77   -18 28.2    3.852    4.734   15.14     6.6   147
2009/05/21    17 47.68   -18 14.2    3.811    4.731   15.07     5.7   152
*************************************************************************

1173 Anchises     H: 8.89   Min: 15.82   Date: 2009/05/11
-------------------------------------------------------------------------
   DATE       RA(2000)   DC(2000)    E.D.     S.D.     Mag     PA      E 
-------------------------------------------------------------------------
2009/05/01    15 15.36   -25 08.6    4.278    5.260   15.94     2.7   166
2009/05/06    15 12.72   -24 58.0    4.258    5.255   15.87     1.9   170
2009/05/11    15 10.03   -24 46.3    4.246    5.250   15.82     1.3   173
2009/05/16    15 07.34   -24 33.7    4.241    5.245   15.82     1.5   172
2009/05/21    15 04.70   -24 20.3    4.244    5.240   15.88     2.2   168
*************************************************************************

1867 Deiphobus     H: 8.61   Min: 15.51   Date: 2009/05/21
-------------------------------------------------------------------------
   DATE       RA(2000)   DC(2000)    E.D.     S.D.     Mag     PA      E 
-------------------------------------------------------------------------
2009/05/01    17 20.41   -39 56.3    4.161    4.934   15.74     8.2   136
2009/05/06    17 18.24   -39 53.5    4.112    4.933   15.68     7.5   141
2009/05/11    17 15.73   -39 48.8    4.068    4.932   15.63     6.7   145
2009/05/16    17 12.92   -39 41.9    4.031    4.931   15.57     5.9   150
2009/05/21    17 09.85   -39 32.9    3.999    4.931   15.51     5.1   154
*************************************************************************

2241 Alcathous     H: 8.64   Min: 15.43   Date: 2009/05/21
-------------------------------------------------------------------------
   DATE       RA(2000)   DC(2000)    E.D.     S.D.     Mag     PA      E 
-------------------------------------------------------------------------
2009/05/01    16 55.41   -29 18.6    4.108    4.960   15.70     6.8   144
2009/05/06    16 53.30   -29 10.6    4.067    4.962   15.63     5.9   149
2009/05/11    16 50.93   -29 01.3    4.032    4.964   15.57     5.0   155
2009/05/16    16 48.34   -28 50.7    4.004    4.966   15.50     4.0   160
2009/05/21    16 45.58   -28 39.0    3.983    4.968   15.43     3.0   165
*************************************************************************

2357 Phereclos     H: 8.94   Min: 15.96   Date: 2009/05/21
-------------------------------------------------------------------------
   DATE       RA(2000)   DC(2000)    E.D.     S.D.     Mag     PA      E 
-------------------------------------------------------------------------
2009/05/01    18 15.17   -20 19.1    4.294    4.966   16.20     9.3   127
2009/05/06    18 14.34   -20 16.6    4.234    4.967   16.15     8.7   132
2009/05/11    18 13.17   -20 14.4    4.179    4.967   16.09     8.0   137
2009/05/16    18 11.69   -20 12.5    4.129    4.967   16.03     7.2   142
2009/05/21    18 09.91   -20 10.7    4.084    4.968   15.96     6.3   147
*************************************************************************

2674 Pandarus     H: 9.00   Min: 15.98   Date: 2009/05/21
-------------------------------------------------------------------------
   DATE       RA(2000)   DC(2000)    E.D.     S.D.     Mag     PA      E 
-------------------------------------------------------------------------
2009/05/01    18 15.87   -21 15.1    4.244    4.915   16.22     9.4   127
2009/05/06    18 15.03   -21 13.5    4.185    4.917   16.16     8.8   132
2009/05/11    18 13.85   -21 12.0    4.132    4.919   16.11     8.0   137
2009/05/16    18 12.35   -21 10.8    4.083    4.921   16.04     7.2   142
2009/05/21    18 10.55   -21 09.8    4.040    4.923   15.98     6.4   147
*************************************************************************

2893 Peiroos     H: 9.23   Min: 15.92   Date: 2009/05/21
-------------------------------------------------------------------------
   DATE       RA(2000)   DC(2000)    E.D.     S.D.     Mag     PA      E 
-------------------------------------------------------------------------
2009/05/01    16 02.60   -05 45.3    3.939    4.878   16.06     4.8   156
2009/05/06    16 00.19   -05 38.0    3.915    4.876   16.00     4.0   160
2009/05/11    15 57.63   -05 31.8    3.897    4.874   15.95     3.4   163
2009/05/16    15 54.97   -05 26.9    3.887    4.871   15.92     3.0   165
2009/05/21    15 52.27   -05 23.4    3.884    4.869   15.92     3.0   165
*************************************************************************

3317 Paris     H: 8.30   Min: 15.07   Date: 2009/05/21
-------------------------------------------------------------------------
   DATE       RA(2000)   DC(2000)    E.D.     S.D.     Mag     PA      E 
-------------------------------------------------------------------------
2009/05/01    17 57.75   +04 46.1    3.959    4.618   15.27    10.2   126
2009/05/06    17 56.68   +04 59.8    3.907    4.615   15.21     9.7   130
2009/05/11    17 55.29   +05 11.7    3.859    4.613   15.16     9.1   134
2009/05/16    17 53.59   +05 21.5    3.817    4.611   15.11     8.6   137
2009/05/21    17 51.61   +05 28.9    3.779    4.609   15.07     8.0   141
*************************************************************************

3451 Mentor     H: 8.10   Min: 15.13   Date: 2009/05/21
-------------------------------------------------------------------------
   DATE       RA(2000)   DC(2000)    E.D.     S.D.     Mag     PA      E 
-------------------------------------------------------------------------
2009/05/01    18 19.16   +04 57.9    4.242    4.832   15.32    10.3   121
2009/05/06    18 18.48   +05 22.5    4.187    4.830   15.27     9.9   125
2009/05/11    18 17.48   +05 45.7    4.135    4.828   15.23     9.4   128
2009/05/16    18 16.17   +06 07.3    4.089    4.826   15.18     8.9   132
2009/05/21    18 14.58   +06 26.9    4.047    4.825   15.13     8.4   136
*************************************************************************

7352 1994 CO     H: 9.00   Min: 15.71   Date: 2009/05/21
-------------------------------------------------------------------------
   DATE       RA(2000)   DC(2000)    E.D.     S.D.     Mag     PA      E 
-------------------------------------------------------------------------
2009/05/01    16 07.14   -11 05.2    4.031    4.972   15.91     4.6   157
2009/05/06    16 04.81   -10 56.1    4.005    4.972   15.84     3.7   161
2009/05/11    16 02.34   -10 47.6    3.986    4.971   15.78     2.9   166
2009/05/16    15 59.76   -10 39.7    3.974    4.971   15.73     2.2   169
2009/05/21    15 57.12   -10 32.6    3.970    4.970   15.71     2.0   170
*************************************************************************
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Brian D. Warner
Palmer Divide Observatory (716)
17995 Bakers Farm Rd.
Colorado Springs, CO 80908