Forum der Vereinigung der Sternfreunde

Comet 154P/Brewington on the morning of 2024 July 9 was magnitude G=14.1 as calculated from 25x30s images taken with no filter in an aperture diameter of 1.7'.

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Cheers, Mike
Arizona

anbei ein 154P Bild von heute morgen, Astrometrica bestimmt lumpige 16m4, während die Helden vom MPC weiterhin 11m1 melden, mit langem Schweif .....

Tach Roland,

die Helligkeitsparameter von alten Kometen werden vom MPC so gut wie nie aktualisiert. Die noch immer angezeigten Werte für Ho und n stammen vermutlich noch aus dem Entdeckungsjahr 19hundertschießmichtot. Ich empfehle Dir mal eine andere Quelle, nämlich das Jet Propulsion Laboratory JPL https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/

Hier folgt eine mit den Default-Elementen für 154P gerechnete Ephemeride Juli bis September - Deine Helligkeit paßt bestens!!!


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JPL/HORIZONS 154P/Brewington 2024-Aug-13 05:34:35
Rec #:90001092 (+COV) Soln.date: 2024-Aug-12_08:17:31 # obs: 2724 (2013-2024)

IAU76/J2000 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs):

EPOCH= 2456756.5 ! 2014-Apr-09.0000000 (TDB) RMSW= n.a.
EC= .6706330897682617 QR= 1.607801752895597 TP= 2456638.9554664139
OM= 343.4870920044983 W= 49.0225555137138 IN= 17.83199216840841
A= 4.881491439939636 MA= 10.74181609620082 ADIST= 8.155181126983676
PER= 10.785418474064 N= .091385076 ANGMOM= .028192801
DAN= 1.8656 DDN= 4.79459 L= 31.10882
B= 13.3672272 MOID= .66749501 TP= 2013-Dec-12.4554664139

Comet physical (GM= km^3/s^2; RAD= km):
GM= n.a. RAD= n.a.
M1= 8.7 M2= 15.3 k1= 25.75 k2= 5. PHCOF= .030
Comet non-gravitational force model (AMRAT=m^2/kg;A1-A3=au/d^2;DT=days;R0=au):
AMRAT= 0. DT= 0.
A1= 4.011077404022E-8 A2= -8.59297811985E-10 A3= 0.
Standard model:
ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808

COMET comments
1: soln ref.= JPL#K242/4, data arc: 2013-07-06 to 2024-08-10
2: k1=25.75, k2=5., phase coef.=0.03;
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Ephemeris / WWW_USER Tue Aug 13 05:34:35 2024 Pasadena, USA / Horizons
*******************************************************************************
Target body name: 154P/Brewington {source: JPL#K242/4}
Center body name: Earth (399) {source: DE441}
Center-site name: GEOCENTRIC
*******************************************************************************
Start time : A.D. 2024-Jul-01 00:00:00.0000 UT
Stop time : A.D. 2024-Sep-30 00:00:00.0000 UT
Step-size : 1440 minutes
*******************************************************************************
Target pole/equ : undefined
Target radii : undefined
Center geodetic : 0.0, 0.0, -6378.137 {E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: 0.0, 0.0, 0.0 {E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : ITRF93 {East-longitude positive}
Center radii : 6378.137, 6378.137, 6356.752 km {Equator_a, b, pole_c}
Target primary : Sun
Vis. interferer : MOON (R_eq= 1737.400) km {source: DE441}
Rel. light bend : Sun {source: DE441}
Rel. lght bnd GM: 1.3271E+11 km^3/s^2
Small-body perts: Yes {source: SB441-N16}
Atmos refraction: NO (AIRLESS)
RA format : HMS
Time format : CAL
Calendar mode : Mixed Julian/Gregorian
EOP file : eop.240812.p241105
EOP coverage : DATA-BASED 1962-JAN-20 TO 2024-AUG-12. PREDICTS-> 2024-NOV-04
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 )
Table cut-offs 3: RA/DEC angular rate ( 0.0=NO )
*******************************************************************************
Initial IAU76/J2000 heliocentric ecliptic osculating elements (au, days, deg.):
EPOCH= 2456756.5 ! 2014-Apr-09.0000000 (TDB) RMSW= n.a.
EC= .6706330897682617 QR= 1.607801752895597 TP= 2456638.9554664139
OM= 343.4870920044983 W= 49.0225555137138 IN= 17.83199216840841
Equivalent ICRF heliocentric cartesian coordinates (au, au/d):
X=-1.875776074911795E-01 Y= 1.555918902527969E+00 Z= 1.311052061138183E+00
VX=-1.425776358739821E-02 VY= 4.545960511259302E-03 VZ= 2.253401302259104E-03
Comet physical (GM= km^3/s^2; RAD= km):
GM= n.a. RAD= n.a.
M1= 8.7 M2= 15.3 k1= 25.75 k2= 5. PHCOF= .030
Comet non-gravitational force model (AMRAT=m^2/kg;A1-A3=au/d^2;DT=days;R0=au):
AMRAT= 0. DT= 0.
A1= 4.011077404022E-8 A2= -8.59297811985E-10 A3= 0.
Standard model:
ALN= .1112620426 NK= 4.6142 NM= 2.15 NN= 5.093 R0= 2.808
******************************************************************************************************************************************************************************
Date__(UT)__HR:MN R.A._____(ICRF)_____DEC T-mag N-mag delta deldot S-O-T /r S-T-O Sky_motion Sky_mot_PA RelVel-ANG Lun_Sky_Brt sky_SNR
******************************************************************************************************************************************************************************
$$SOE
2024-Jul-01 00:00 03 59 40.77 +31 11 47.9 15.487 18.728 2.26184996502560 -3.0028859 36.4879 /L 22.7129 1.8949964 71.777892 -3.321678 n.a. n.a.
2024-Jul-02 00:00 04 03 02.84 +31 25 58.4 15.496 18.731 2.26014192998211 -2.9125587 36.6896 /L 22.8045 1.8905648 72.131413 -3.232061 n.a. n.a.
2024-Jul-03 00:00 04 06 25.35 +31 39 50.8 15.506 18.734 2.25848538224824 -2.8245689 36.8924 /L 22.8950 1.8859681 72.488089 -3.144656 n.a. n.a.
2024-Jul-04 00:00 04 09 48.25 +31 53 25.1 15.516 18.738 2.25687899947993 -2.7388216 37.0965 /L 22.9845 1.8812076 72.847810 -3.059362 n.a. n.a.
2024-Jul-05 00:00 04 13 11.52 +32 06 41.1 15.527 18.741 2.25532151167161 -2.6552322 37.3020 /L 23.0728 1.8762863 73.210462 -2.976089 n.a. n.a.
2024-Jul-06 00:00 04 16 35.13 +32 19 38.6 15.538 18.745 2.25381169259448 -2.5737351 37.5089 /L 23.1602 1.8712080 73.575927 -2.894765 n.a. n.a.
2024-Jul-07 00:00 04 19 59.04 +32 32 17.5 15.550 18.749 2.25234834683541 -2.4942897 37.7171 /L 23.2465 1.8659774 73.944089 -2.815345 n.a. n.a.
2024-Jul-08 00:00 04 23 23.22 +32 44 37.8 15.563 18.752 2.25093029463366 -2.4168823 37.9269 /L 23.3318 1.8605999 74.314823 -2.737816 n.a. n.a.
2024-Jul-09 00:00 04 26 47.65 +32 56 39.2 15.576 18.756 2.24955635690770 -2.3415238 38.1382 /L 23.4160 1.8550806 74.688003 -2.662191 n.a. n.a.
2024-Jul-10 00:00 04 30 12.28 +33 08 21.7 15.590 18.761 2.24822534243020 -2.2682443 38.3511 /L 23.4993 1.8494247 75.063498 -2.588509 n.a. n.a.
2024-Jul-11 00:00 04 33 37.10 +33 19 45.2 15.604 18.765 2.24693603825128 -2.1970879 38.5657 /L 23.5816 1.8436371 75.441173 -2.516826 n.a. n.a.
2024-Jul-12 00:00 04 37 02.05 +33 30 49.6 15.619 18.769 2.24568720352696 -2.1281063 38.7819 /L 23.6630 1.8377223 75.820890 -2.447210 n.a. n.a.
2024-Jul-13 00:00 04 40 27.12 +33 41 35.0 15.634 18.774 2.24447756614831 -2.0613556 38.9998 /L 23.7435 1.8316848 76.202507 -2.379736 n.a. n.a.
2024-Jul-14 00:00 04 43 52.27 +33 52 01.2 15.650 18.778 2.24330582108692 -1.9968936 39.2196 /L 23.8230 1.8255288 76.585880 -2.314482 n.a. n.a.
2024-Jul-15 00:00 04 47 17.46 +34 02 08.2 15.667 18.783 2.24217062914168 -1.9347811 39.4412 /L 23.9017 1.8192586 76.970861 -2.251533 n.a. n.a.
2024-Jul-16 00:00 04 50 42.66 +34 11 56.0 15.683 18.788 2.24107061471578 -1.8750841 39.6647 /L 23.9795 1.8128787 77.357302 -2.190983 n.a. n.a.
2024-Jul-17 00:00 04 54 07.84 +34 21 24.6 15.701 18.792 2.24000436133810 -1.8178790 39.8902 /L 24.0564 1.8063935 77.745050 -2.132940 n.a. n.a.
2024-Jul-18 00:00 04 57 32.96 +34 30 34.0 15.719 18.797 2.23897040392972 -1.7632588 40.1177 /L 24.1326 1.7998079 78.133948 -2.077533 n.a. n.a.
2024-Jul-19 00:00 05 00 57.99 +34 39 24.3 15.737 18.802 2.23796721745341 -1.7113392 40.3472 /L 24.2080 1.7931261 78.523833 -2.024923 n.a. n.a.
2024-Jul-20 00:00 05 04 22.89 +34 47 55.4 15.756 18.808 2.23699320273228 -1.6622613 40.5789 /L 24.2826 1.7863521 78.914536 -1.975304 n.a. n.a.
2024-Jul-21 00:00 05 07 47.64 +34 56 07.4 15.776 18.813 2.23604667186937 -1.6161902 40.8128 /L 24.3564 1.7794885 79.305877 -1.928905 n.a. n.a.
2024-Jul-22 00:00 05 11 12.19 +35 04 00.4 15.796 18.818 2.23512583738930 -1.5733032 41.0489 /L 24.4296 1.7725364 79.697672 -1.885976 n.a. n.a.
2024-Jul-23 00:00 05 14 36.52 +35 11 34.4 15.816 18.824 2.23422880999304 -1.5337720 41.2874 /L 24.5021 1.7654949 80.089731 -1.846767 n.a. n.a.
2024-Jul-24 00:00 05 18 00.58 +35 18 49.5 15.837 18.829 2.23335360862436 -1.4977388 41.5282 /L 24.5739 1.7583611 80.481864 -1.811499 n.a. n.a.
2024-Jul-25 00:00 05 21 24.35 +35 25 45.9 15.858 18.835 2.23249818323682 -1.4652976 41.7715 /L 24.6450 1.7511306 80.873884 -1.780341 n.a. n.a.
2024-Jul-26 00:00 05 24 47.79 +35 32 23.5 15.880 18.840 2.23166044657957 -1.4364827 42.0174 /L 24.7156 1.7437984 81.265614 -1.753395 n.a. n.a.
2024-Jul-27 00:00 05 28 10.85 +35 38 42.6 15.902 18.846 2.23083830867620 -1.4112702 42.2659 /L 24.7855 1.7363599 81.656883 -1.730692 n.a. n.a.
2024-Jul-28 00:00 05 31 33.51 +35 44 43.3 15.925 18.852 2.23002970777356 -1.3895885 42.5170 /L 24.8548 1.7288110 82.047526 -1.712205 n.a. n.a.
2024-Jul-29 00:00 05 34 55.72 +35 50 25.6 15.948 18.858 2.22923263386367 -1.3713325 42.7709 /L 24.9235 1.7211493 82.437386 -1.697868 n.a. n.a.
2024-Jul-30 00:00 05 38 17.44 +35 55 49.8 15.971 18.864 2.22844514374636 -1.3563781 43.0276 /L 24.9916 1.7133735 82.826312 -1.687585 n.a. n.a.
2024-Jul-31 00:00 05 41 38.65 +36 00 55.9 15.995 18.870 2.22766536859415 -1.3445936 43.2871 /L 25.0591 1.7054836 83.214153 -1.681254 n.a. n.a.
2024-Aug-01 00:00 05 44 59.29 +36 05 44.3 16.019 18.876 2.22689151570234 -1.3358483 43.5495 /L 25.1260 1.6974809 83.600765 -1.678767 n.a. n.a.
2024-Aug-02 00:00 05 48 19.34 +36 10 14.9 16.044 18.882 2.22612186594897 -1.3300189 43.8149 /L 25.1924 1.6893677 83.986006 -1.680027 n.a. n.a.
2024-Aug-03 00:00 05 51 38.75 +36 14 28.1 16.068 18.888 2.22535476805665 -1.3269946 44.0832 /L 25.2581 1.6811472 84.369737 -1.684951 n.a. n.a.
2024-Aug-04 00:00 05 54 57.48 +36 18 24.0 16.094 18.895 2.22458863045667 -1.3266798 44.3546 /L 25.3233 1.6728232 84.751822 -1.693472 n.a. n.a.
2024-Aug-05 00:00 05 58 15.52 +36 22 02.8 16.119 18.901 2.22382191152854 -1.3289973 44.6290 /L 25.3879 1.6644001 85.132127 -1.705548 n.a. n.a.
2024-Aug-06 00:00 06 01 32.80 +36 25 24.7 16.145 18.907 2.22305310911650 -1.3338877 44.9066 /L 25.4519 1.6558823 85.510521 -1.721158 n.a. n.a.
2024-Aug-07 00:00 06 04 49.32 +36 28 30.0 16.172 18.914 2.22228075031977 -1.3413086 45.1873 /L 25.5153 1.6472744 85.886875 -1.740305 n.a. n.a.
2024-Aug-08 00:00 06 08 05.02 +36 31 18.9 16.198 18.920 2.22150338246844 -1.3512319 45.4712 /L 25.5782 1.6385811 86.261061 -1.763010 n.a. n.a.
2024-Aug-09 00:00 06 11 19.88 +36 33 51.6 16.225 18.927 2.22071956590234 -1.3636400 45.7583 /L 25.6404 1.6298065 86.632952 -1.789311 n.a. n.a.
2024-Aug-10 00:00 06 14 33.87 +36 36 08.3 16.253 18.933 2.21992786873205 -1.3785231 46.0487 /L 25.7021 1.6209550 87.002424 -1.819258 n.a. n.a.
2024-Aug-11 00:00 06 17 46.96 +36 38 09.4 16.280 18.940 2.21912686328899 -1.3958762 46.3424 /L 25.7633 1.6120304 87.369355 -1.852907 n.a. n.a.
2024-Aug-12 00:00 06 20 59.11 +36 39 55.0 16.308 18.946 2.21831512354165 -1.4156985 46.6394 /L 25.8239 1.6030369 87.733627 -1.890325 n.a. n.a.
2024-Aug-13 00:00 06 24 10.31 +36 41 25.5 16.336 18.953 2.21749122241041 -1.4379949 46.9399 /L 25.8839 1.5939785 88.095121 -1.931585 n.a. n.a.
2024-Aug-14 00:00 06 27 20.52 +36 42 41.1 16.365 18.960 2.21665372766554 -1.4627792 47.2437 /L 25.9433 1.5848593 88.453725 -1.976779 n.a. n.a.
2024-Aug-15 00:00 06 30 29.71 +36 43 42.1 16.393 18.966 2.21580119499725 -1.4900806 47.5510 /L 26.0022 1.5756839 88.809323 -2.026017 n.a. n.a.
2024-Aug-16 00:00 06 33 37.87 +36 44 28.7 16.422 18.973 2.21493215704669 -1.5199510 47.8619 /L 26.0606 1.5664564 89.161801 -2.079448 n.a. n.a.
2024-Aug-17 00:00 06 36 44.97 +36 45 01.3 16.451 18.980 2.21404510794924 -1.5524730 48.1762 /L 26.1184 1.5571811 89.511038 -2.137264 n.a. n.a.
2024-Aug-18 00:00 06 39 50.98 +36 45 20.1 16.481 18.986 2.21313848455052 -1.5877624 48.4942 /L 26.1757 1.5478612 89.856907 -2.199711 n.a. n.a.
2024-Aug-19 00:00 06 42 55.89 +36 45 25.4 16.510 18.993 2.21221064789560 -1.6259640 48.8158 /L 26.2325 1.5384980 90.199271 -2.267085 n.a. n.a.
2024-Aug-20 00:00 06 45 59.67 +36 45 17.6 16.540 19.000 2.21125987106744 -1.6672338 49.1411 /L 26.2887 1.5290910 90.537989 -2.339709 n.a. n.a.
2024-Aug-21 00:00 06 49 02.31 +36 44 56.9 16.570 19.006 2.21028434022118 -1.7117117 49.4702 /L 26.3443 1.5196367 90.872915 -2.417895 n.a. n.a.
2024-Aug-22 00:00 06 52 03.78 +36 44 23.6 16.601 19.013 2.20928217299954 -1.7594903 49.8031 /L 26.3995 1.5101296 91.203910 -2.501906 n.a. n.a.
2024-Aug-23 00:00 06 55 04.06 +36 43 38.1 16.631 19.020 2.20825145263124 -1.8105938 50.1399 /L 26.4541 1.5005627 91.530848 -2.591915 n.a. n.a.
2024-Aug-24 00:00 06 58 03.14 +36 42 40.6 16.662 19.027 2.20719026997516 -1.8649724 50.4805 /L 26.5082 1.4909287 91.853618 -2.688000 n.a. n.a.
2024-Aug-25 00:00 07 01 00.98 +36 41 31.5 16.693 19.033 2.20609676339555 -1.9225142 50.8252 /L 26.5617 1.4812216 92.172123 -2.790152 n.a. n.a.
2024-Aug-26 00:00 07 03 57.58 +36 40 11.1 16.724 19.040 2.20496914880448 -1.9830664 51.1739 /L 26.6146 1.4714366 92.486282 -2.898301 n.a. n.a.
2024-Aug-27 00:00 07 06 52.91 +36 38 39.8 16.755 19.047 2.20380573719054 -2.0464557 51.5267 /L 26.6669 1.4615707 92.796022 -3.012348 n.a. n.a.
2024-Aug-28 00:00 07 09 46.96 +36 36 57.8 16.786 19.054 2.20260494122456 -2.1125054 51.8837 /L 26.7186 1.4516224 93.101280 -3.132183 n.a. n.a.
2024-Aug-29 00:00 07 12 39.69 +36 35 05.4 16.818 19.060 2.20136527446264 -2.1810440 52.2448 /L 26.7696 1.4415912 93.401997 -3.257702 n.a. n.a.
2024-Aug-30 00:00 07 15 31.10 +36 33 03.1 16.849 19.067 2.20008534654178 -2.2519106 52.6102 /L 26.8200 1.4314776 93.698118 -3.388813 n.a. n.a.
2024-Aug-31 00:00 07 18 21.17 +36 30 51.1 16.881 19.073 2.19876385667631 -2.3249561 52.9798 /L 26.8696 1.4212828 93.989595 -3.525439 n.a. n.a.
2024-Sep-01 00:00 07 21 09.87 +36 28 29.7 16.913 19.080 2.19739958661605 -2.4000438 53.3537 /L 26.9185 1.4110086 94.276380 -3.667521 n.a. n.a.
2024-Sep-02 00:00 07 23 57.20 +36 25 59.4 16.945 19.087 2.19599139345238 -2.4770495 53.7319 /L 26.9667 1.4006569 94.558434 -3.815015 n.a. n.a.
2024-Sep-03 00:00 07 26 43.14 +36 23 20.3 16.977 19.093 2.19453820232370 -2.5558617 54.1144 /L 27.0141 1.3902302 94.835716 -3.967896 n.a. n.a.
2024-Sep-04 00:00 07 29 27.68 +36 20 32.9 17.010 19.100 2.19303899906016 -2.6363817 54.5014 /L 27.0607 1.3797309 95.108192 -4.126160 n.a. n.a.
2024-Sep-05 00:00 07 32 10.79 +36 17 37.4 17.042 19.106 2.19149282294529 -2.7185230 54.8927 /L 27.1065 1.3691616 95.375829 -4.289819 n.a. n.a.
2024-Sep-06 00:00 07 34 52.48 +36 14 34.2 17.074 19.112 2.18989875989846 -2.8022104 55.2885 /L 27.1513 1.3585251 95.638595 -4.458905 n.a. n.a.
2024-Sep-07 00:00 07 37 32.72 +36 11 23.6 17.107 19.119 2.18825593638682 -2.8873785 55.6888 /L 27.1954 1.3478239 95.896461 -4.633468 n.a. n.a.
2024-Sep-08 00:00 07 40 11.51 +36 08 05.8 17.139 19.125 2.18656351422507 -2.9739699 56.0935 /L 27.2384 1.3370606 96.149399 -4.813569 n.a. n.a.
2024-Sep-09 00:00 07 42 48.85 +36 04 41.4 17.172 19.131 2.18482068613086 -3.0619348 56.5028 /L 27.2806 1.3262378 96.397382 -4.999286 n.a. n.a.
2024-Sep-10 00:00 07 45 24.71 +36 01 10.4 17.205 19.137 2.18302667153217 -3.1512309 56.9166 /L 27.3218 1.3153582 96.640385 -5.190711 n.a. n.a.
2024-Sep-11 00:00 07 47 59.09 +35 57 33.3 17.238 19.143 2.18118071172838 -3.2418252 57.3349 /L 27.3620 1.3044243 96.878381 -5.387952 n.a. n.a.
2024-Sep-12 00:00 07 50 31.99 +35 53 50.3 17.271 19.149 2.17928206316614 -3.3336991 57.7579 /L 27.4012 1.2934393 97.111346 -5.591145 n.a. n.a.
2024-Sep-13 00:00 07 53 03.40 +35 50 01.8 17.303 19.155 2.17732998743385 -3.4268549 58.1855 /L 27.4393 1.2824061 97.339250 -5.800462 n.a. n.a.
2024-Sep-14 00:00 07 55 33.31 +35 46 08.1 17.336 19.161 2.17532373683690 -3.5213237 58.6177 /L 27.4764 1.2713277 97.562054 -6.016132 n.a. n.a.
2024-Sep-15 00:00 07 58 01.72 +35 42 09.4 17.369 19.167 2.17326253545615 -3.6171729 59.0547 /L 27.5123 1.2602065 97.779709 -6.238454 n.a. n.a.
2024-Sep-16 00:00 08 00 28.63 +35 38 06.1 17.402 19.173 2.17114555773584 -3.7145064 59.4964 /L 27.5472 1.2490435 97.992146 -6.467806 n.a. n.a.
2024-Sep-17 00:00 08 02 54.03 +35 33 58.4 17.436 19.179 2.16897190971535 -3.8134541 59.9428 /L 27.5809 1.2378378 98.199278 -6.704638 n.a. n.a.
2024-Sep-18 00:00 08 05 17.92 +35 29 46.6 17.469 19.184 2.16674062067173 -3.9141467 60.3940 /L 27.6135 1.2265854 98.401005 -6.949433 n.a. n.a.
2024-Sep-19 00:00 08 07 40.30 +35 25 31.1 17.502 19.190 2.16445065271301 -4.0166799 60.8502 /L 27.6448 1.2152794 98.597216 -7.202653 n.a. n.a.
2024-Sep-20 00:00 08 10 01.16 +35 21 12.1 17.535 19.195 2.16210093091493 -4.1210817 61.3112 /L 27.6749 1.2039109 98.787813 -7.464674 n.a. n.a.
2024-Sep-21 00:00 08 12 20.49 +35 16 50.0 17.568 19.200 2.15969038844030 -4.2272952 61.7772 /L 27.7038 1.1924699 98.972708 -7.735749 n.a. n.a.
2024-Sep-22 00:00 08 14 38.30 +35 12 24.9 17.601 19.206 2.15721801476254 -4.3351851 62.2483 /L 27.7313 1.1809474 99.151841 -8.016000 n.a. n.a.
2024-Sep-23 00:00 08 16 54.57 +35 07 57.3 17.634 19.211 2.15468289500624 -4.4445600 62.7244 /L 27.7575 1.1693357 99.325168 -8.305450 n.a. n.a.
2024-Sep-24 00:00 08 19 09.31 +35 03 27.3 17.667 19.216 2.15208423396035 -4.5552013 63.2057 /L 27.7822 1.1576295 99.492663 -8.604066 n.a. n.a.
2024-Sep-25 00:00 08 21 22.49 +34 58 55.4 17.700 19.221 2.14942136506748 -4.6668853 63.6922 /L 27.8055 1.1458249 99.654310 -8.911797 n.a. n.a.
2024-Sep-26 00:00 08 23 34.12 +34 54 21.7 17.733 19.226 2.14669374881631 -4.7793971 64.1839 /L 27.8273 1.1339198 99.810094 -9.228599 n.a. n.a.
2024-Sep-27 00:00 08 25 44.19 +34 49 46.7 17.766 19.230 2.14390096571215 -4.8925363 64.6808 /L 27.8475 1.1219130 99.960005 -9.554452 n.a. n.a.
2024-Sep-28 00:00 08 27 52.69 +34 45 10.4 17.799 19.235 2.14104270771323 -5.0061172 65.1831 /L 27.8661 1.1098038 100.10403 -9.889359 n.a. n.a.
2024-Sep-29 00:00 08 29 59.62 +34 40 33.3 17.832 19.240 2.13811877023538 -5.1199668 65.6908 /L 27.8830 1.0975921 100.24216 -10.23335 n.a. n.a.
2024-Sep-30 00:00 08 32 04.97 +34 35 55.6 17.865 19.244 2.13512904540173 -5.2339228 66.2038 /L 27.8982 1.0852781 100.37439 -10.58646 n.a. n.a.
$$EOE
******************************************************************************************************************************************************************************
Column meaning:

TIME

Times PRIOR to 1962 are UT1, a mean-solar time closely related to the
prior but now-deprecated GMT. Times AFTER 1962 are in UTC, the current
civil or "wall-clock" time-scale. UTC is kept within 0.9 seconds of UT1
using integer leap-seconds for 1972 and later years.

Conversion from the internal Barycentric Dynamical Time (TDB) of solar
system dynamics to the non-uniform civil UT time-scale requested for output
has not been determined for UTC times after the next July or January 1st.
Therefore, the last known leap-second is used as a constant over future
intervals.

Time tags refer to the UT time-scale conversion from TDB on Earth
regardless of observer location within the solar system, although clock
rates may differ due to the local gravity field and no analog to "UT"
may be defined for that location.

Any 'b' symbol in the 1st-column denotes a B.C. date. First-column blank
(" ") denotes an A.D. date.

CALENDAR SYSTEM

Mixed calendar mode was active such that calendar dates after AD 1582-Oct-15
(if any) are in the modern Gregorian system. Dates prior to 1582-Oct-5 (if any)
are in the Julian calendar system, which is automatically extended for dates
prior to its adoption on 45-Jan-1 BC. The Julian calendar is useful for
matching historical dates. The Gregorian calendar more accurately corresponds
to the Earth's orbital motion and seasons. A "Gregorian-only" calendar mode is
available if such physical events are the primary interest.

NOTE: "n.a." in output means quantity "not available" at the print-time.

'R.A._____(ICRF)_____DEC' =
Astrometric right ascension and declination of the target center with
respect to the observing site (coordinate origin) in the reference frame of
the planetary ephemeris (ICRF). Compensated for down-leg light-time delay
aberration.

Units: RA in hours-minutes-seconds of time, HH MM SS.ff{ffff}
DEC in degrees-minutes-seconds of arc, sDD MN SC.f{ffff}

'T-mag N-mag' =
Comets' apparent visual total magnitude ("T-mag") and nuclear magnitude
("N-mag") using the standard IAU model:

T-mag= M1 + 5*log10(delta) + k1*log10(r)
N-mag= M2 + 5*log10(delta) + k2*log10(r) + phcof*beta

Units: MAGNITUDES

'delta deldot' =
Apparent range ("delta", light-time aberrated) and range-rate ("delta-dot")
of the target center relative to the observer. A positive "deldot" means the
target center is moving away from the observer, negative indicates movement
toward the observer. Units: AU and KM/S

'S-O-T /r' =
Sun-Observer-Target apparent SOLAR ELONGATION ANGLE seen from the observers'
location at print-time.

The '/r' column provides a code indicating the targets' apparent position
relative to the Sun in the observers' sky, as described below:

Case A: For an observing location on the surface of a rotating body, that
body rotational sense is considered:

/T indicates target TRAILS Sun (evening sky: rises and sets AFTER Sun)
/L indicates target LEADS Sun (morning sky: rises and sets BEFORE Sun)

Case B: For an observing point that does not have a rotational model (such
as a spacecraft), the "leading" and "trailing" condition is defined by the
observers' heliocentric ORBITAL motion:

* If continuing in the observers' current direction of heliocentric
motion would encounter the targets' apparent longitude first, followed
by the Sun's, the target LEADS the Sun as seen by the observer.

* If the Sun's apparent longitude would be encountered first, followed
by the targets', the target TRAILS the Sun.

Two other codes can be output:
/* indicates observer is Sun-centered (undefined)
/? Target is aligned with Sun center (no lead or trail)

The S-O-T solar elongation angle is numerically the minimum separation
angle of the Sun and target in the sky in any direction. It does NOT indicate
the amount of separation in the leading or trailing directions, which would
be defined along the equator of a spherical coordinate system.

Units: DEGREES

'S-T-O' =
The Sun-Target-Observer angle; the interior vertex angle at target center
formed by a vector from the target to the apparent center of the Sun (at
reflection time on the target) and the apparent vector from target 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

'Sky_motion Sky_mot_PA RelVel-ANG' =
Total apparent angular rate of the target in the plane-of-sky. "Sky_mot_PA"
is the position angle of the target's direction of motion in the plane-of-sky,
measured counter-clockwise from the apparent of-date north pole direction.
"RelVel-ANG" is the flight path angle of the target's relative motion with
respect to the observer's line-of-sight, in the range [-90,+90], where positive
values indicate motion away from the observer, negative values are toward the
observer:

-90 = target is moving directly toward the observer
0 = target is moving at right angles to the observer's line-of-sight
+90 = target is moving directly away from the observer

UNITS: ARCSECONDS/MINUTE, DEGREES, DEGREES

'Lun_Sky_Brt sky_SNR' =
Sky brightness due to moonlight scattered by Earth's atmosphere at the
target's position in the sky. "sky_SNR" is the visual signal-to-noise ratio
(SNR) of the target's surface brightness relative to background sky. Output
only for topocentric Earth observers when both the Moon and target are above
the local horizon and the Sun is in astronomical twilight (or further) below
the horizon, and the target is not the Moon or Sun. If all conditions are
not met, "n.a." is output. Galactic brightness, local sky light-pollution
and weather are NOT considered. Lunar opposition surge is considered. The
value returned is accurate under ideal conditions at the approximately 8-23%
level, so is a useful but not definitive value.

If the target-body radius is also known, "sky_SNR" is output. This is the
approximate visual signal-to-noise ratio of the target's brightness divided
by lunar sky brightness. When sky_SNR < 1, the target is dimmer than the
ideal moonlight-scattering background sky, so unlikely to be detectable at
visual wavelengths. In practice, visibility requires sky_SNR > 1 and a
detector sensitive enough to reach the target's magnitude, even if it isn't
washed out by moonlight. When relating magnitudes and brightness values,
keep in mind their logarithmic relationship m2-m1 = -2.5*log_10(b2/b1).

UNITS: VISUAL MAGNITUDES / ARCSECOND^2, and unitless ratio

Computations by ...

Solar System Dynamics Group, Horizons On-Line Ephemeris System
4800 Oak Grove Drive, Jet Propulsion Laboratory
Pasadena, CA 91109 USA

General site: https://ssd.jpl.nasa.gov/
Mailing list: https://ssd.jpl.nasa.gov/email_list.html
System news : https://ssd.jpl.nasa.gov/horizons/news.html
User Guide : https://ssd.jpl.nasa.gov/horizons/manual.html
Connect : browser https://ssd.jpl.nasa.gov/horizons/app.html#/x
API https://ssd-api.jpl.nasa.gov/doc/horizons.html
command-line telnet ssd.jpl.nasa.gov 6775
e-mail/batch https://ssd.jpl.nasa.gov/ftp/ssd/hrzn_batch.txt
scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS
Author : Jon.D.Giorgini@jpl.nasa.gov

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

_________________
Michael Möller (MMI)

Roland, now I know why I could not find 154P a couple mornings ago with the 50mm f/3.5 setup which can only find comets down to about magnitude 16 on a perfectly clear night. What is interesting about this comet is that during its time around perihelion, magnitude reports ranged from magnitude 10 to 17 which makes one wonder if this comet was having some temporary outbursts that quickly dissipated or if reports were made on stars instead of the comet in this very crowded star field. The nice thing about software like Astrometrica, it takes the human element out of the equation once one figures out the correct parameters for the equipment setup being used. Seiichi Yoshida's curves suggest the comet should be about magnitude 13-14 right now, but from what I have observed the comet has been several magnitudes fainter than predicted during this orbit into the inner solar system. It looks like Michael's JPL data is predicting the magnitude fairly accurately right now compared to the MPC.

_________________
Cheers, Mike
Arizona

I should clarify my last post. When Uwe, Otto and some others make visual magnitude estimates of comets I find those estimates to be very reliable and they always fit into the statistical mean curve of what both visual and electronic estimates are observing when taking into consideration an accepted coma size. But statistically when an estimate is well outside the mean, either the comet has had an unexpected event which will be verified by other observations, or the estimate simply can't be taken seriously and should be rejected from the data.

_________________
Cheers, Mike
Arizona

@michael: interessant, dass das MPC die Daten periodischer Kometen nicht updated wusste ich garnicht ...... Ansonsten habe ich natürlich keine 11m erwartet, es gibt ja andere Quellen (Yoshida, COBS). Das JPL Interface finde ich etwas unhandlich.

Nun bin ich doch neugierig geworden und habe mir bei Gary Kronk's Cometography mal die Eintragung zu 154P angesehen. Der Komet wurde am 28. August 1992 entdeckt. C.S.Morris (30.08.) und A.Hale (31.08) schätzten den Kometen zu 11.5 mag. Ich habe für den 30.08.92 daraus mal die absolute Helligkeit mit 2.5n=10 berechnet: Ho=7.0 und bin fast vom Hocker gefallen. Das MPC benutzt tatsächlich die photometrischen Parameter von 1992!!!

Bei dem Unterschied von 5 Größenklassen zur aktuellen Helligkeit kann eigentlich mit Sicherheit angenommen werden, dass 154P im August 1992 einen Ausbruch hatte.

Auch in SuW wird die Helligkeit mit ca. 11 mag angegeben, ein Indiz, dass Uwe auch nur mit Wasser kocht, so wie ich es über 21 Jahre lang gemacht habe. So'n Schiet...

MOE (Michael Möller)

_________________
Michael Möller (MMI)

Michael, thank you for your research into what may explain why 154P is much fainter than the MPC predictions. I enjoyed your thoughts and humor about what you have discovered! Evidently JPL is using more recent data, not sure what Seiichi uses to determine his magnitude curves. As usual, Roland lets us know when the MPC has it wrong, which is always interesting to hear. The only question is how did a couple observations find this comet to be magnitude 10 around perihelion on 2024 June 12? It would be nice if these observations included some images to support such brightness. If these magnitude observations are correct, the comet sure did fade quickly since my 2024 July 9 observation found the comet to be magnitude G=14.1. Maybe an eruption which quickly dispersed, but most other observations reported at the same time had the comet at magnitudes 12 to 16, still a very wide range. I can find no images until the second week of July of this comet and none of them observed a bright comet. I tend to think the comet probably never got much brighter than magnitude 13 and the magnitude 10 observations were not very accurate since the comet was just above the eastern horizon as morning twilight appeared. By the way, if you look at the comet image pages you will find that Roland has been very active lately with many images of faint comets including magnitude calculations using Astrometrica, well done Roland.

_________________
Cheers, Mike
Arizona

> dass Uwe auch nur mit Wasser kocht

Als ich das geschrieben habe, gab es noch keine frischen Messungen. Ich habe mich auf das Perihel 2013/2014 gestützt. Damals erreichte er ca. 10 mag.

_________________
Uwe Pilz, Fachgruppen Kometen und Astrophysik/Algorithmen.
Oft benutzte Instrumente: Fujinon 16x70 FMT-SX-2, TMB Apo 105/650, Skywatcher Evostar 120/900 ED, Ninja Dobson 320/1440, Smartscope Dwarf-3

Lieber Uwe,

da habe ich nicht aufgepaßt und bitte um Entschuldigung.

Heute Vormittag habe ich auf COBS herumgestöbrt - 154P - und das Merkwürdige ist, dass für den aktuellen Beobachtungszeitraum kaum visuelle Schätzungen vorliegen. Im Vergleich mit den vorausgegangenen Periheldurchgängen fällt mir der große Unterschied zwischen visuellen und CCD-Helligkeiten auf. Ist das so oder phantasiere ich?

cs
MOE

_________________
Michael Möller (MMI)

> große Unterschied zwischen visuellen und CCD-Helligkeiten auf.

Das hatten wir hier schon öfter. Die normalen CCD-Helligkeiten benutzen eine 10"-Apertur, also nur den inneren Teil. Je größer und diffuser der Komet ist, desto größer die Abweichung. 3 mag sind keine Seltenheit.
Von diesem Perihel haben wir diese Gesamthelligkeiten:

2024 07 30.08  Z 14.7 BG 27.9L 2A023   1                        FRI02I 
2024 07 29.07  Z 14.9 BG 27.9L 2a511   0.7                      FRI02I 
2024 07 02.10  S 10.1 TK 20.3T10 100   3.5  2/           ICQ XX GON05  
2024 06 13.35  M 11.6 AQ 30.0L 5 100   1    3/           ICQ XX DES01  
2024 06 12.36  M 11.9 AQ 30.0L 5 100   1    3            ICQ XX DES01  
2024 06 11.12  S  9.7 TK 20.3T10 100   3    2/           ICQ XX GON05  

Die ersten beiden von Steffen (FRI02I ) sind elektronisch, erfassen aber die ganze Koma. Mr. Gonzales (GON05 )liegt oft deutlich höher, ich blende ihn bei meinen Analysen aus. Und da bin ich nicht der einzige.

_________________
Uwe Pilz, Fachgruppen Kometen und Astrophysik/Algorithmen.
Oft benutzte Instrumente: Fujinon 16x70 FMT-SX-2, TMB Apo 105/650, Skywatcher Evostar 120/900 ED, Ninja Dobson 320/1440, Smartscope Dwarf-3

Der Komet ist schon sehr diffus. Auch mit dem RASA11 habe ich da bei tief stehendem Kometen gut zu tun, um ihn bei 14 ... 15 mag deutlich drauf zu haben. Anbei das Bild vom Morgen des 11.08.2024.

Viele Grüße