C/1997 J2 (Meunier-Dupouy)
| Parameter |
Value |
| Designation |
C/1997 J2 (Meunier-Dupouy) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1998-03-10T10:24:04.697280Z |
| Orbit solution date (soln_date, UTC) |
2022-02-03T20:42:52Z |
| Obs used |
1420 |
| NEO |
- |
| M1 |
8.400 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1998-01-22.0000000 |
| e |
1.00055829 |
| q (au) |
3.051149 |
| a (au) |
-5465.167454 |
| i (deg) |
91.273399 |
| Ω (om, deg) |
148.844533 |
| ω (w, deg) |
122.671679 |
| M (ma, deg) |
-0.000116 |
Magnitude
Scatter + Global Linear
$$
M_a = (3.859 + 3.586\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
3.859 |
| n |
3.586 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
10.000 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1997-05-07 |
1998-03-10 |
-1.5585 |
+0.533 |
| 1998-03-10 |
1999-10-09 |
+7.0916 |
-3.331 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
06:29:34.18 |
-66:24:14.2 |
HIP 30775 |
23.07 |
| 2026-02-03 12:00 |
06:29:29.53 |
-66:23:50.9 |
HIP 31003 |
23.09 |
| 2026-02-04 00:00 |
06:29:24.91 |
-66:23:27.3 |
HIP 31003 |
22.82 |
| 2026-02-04 12:00 |
06:29:20.33 |
-66:23:03.5 |
HIP 31003 |
22.57 |
| 2026-02-05 00:00 |
06:29:15.79 |
-66:22:39.4 |
HIP 31003 |
22.32 |
| 2026-02-05 12:00 |
06:29:11.28 |
-66:22:15.1 |
HIP 31003 |
22.07 |
| 2026-02-06 00:00 |
06:29:06.81 |
-66:21:50.5 |
HIP 31003 |
21.84 |
| 2026-02-06 12:00 |
06:29:02.38 |
-66:21:25.6 |
HIP 31003 |
21.62 |
| 2026-02-07 00:00 |
06:28:57.98 |
-66:21:00.5 |
HIP 31003 |
21.41 |
| 2026-02-07 12:00 |
06:28:53.62 |
-66:20:35.2 |
HIP 31003 |
21.20 |
| 2026-02-08 00:00 |
06:28:49.30 |
-66:20:09.6 |
HIP 31003 |
21.01 |
| 2026-02-08 12:00 |
06:28:45.02 |
-66:19:43.8 |
HIP 31003 |
20.83 |
| 2026-02-09 00:00 |
06:28:40.77 |
-66:19:17.7 |
HIP 31003 |
20.66 |
| 2026-02-09 12:00 |
06:28:36.57 |
-66:18:51.4 |
HIP 31003 |
20.50 |
| 2026-02-10 00:00 |
06:28:32.40 |
-66:18:24.8 |
HIP 31003 |
20.35 |
| 2026-02-10 12:00 |
06:28:28.27 |
-66:17:58.0 |
HIP 31003 |
20.21 |
| 2026-02-11 00:00 |
06:28:24.19 |
-66:17:31.0 |
HIP 31003 |
20.09 |
| 2026-02-11 12:00 |
06:28:20.14 |
-66:17:03.7 |
HIP 31003 |
19.98 |
| 2026-02-12 00:00 |
06:28:16.13 |
-66:16:36.3 |
HIP 31003 |
19.88 |
| 2026-02-12 12:00 |
06:28:12.17 |
-66:16:08.6 |
HIP 31003 |
19.80 |
| 2026-02-13 00:00 |
06:28:08.25 |
-66:15:40.6 |
HIP 31003 |
19.73 |
| 2026-02-13 12:00 |
06:28:04.36 |
-66:15:12.5 |
HIP 31003 |
19.67 |
| 2026-02-14 00:00 |
06:28:00.53 |
-66:14:44.1 |
HIP 31003 |
19.62 |
| 2026-02-14 12:00 |
06:27:56.73 |
-66:14:15.5 |
HIP 31003 |
19.59 |
| 2026-02-15 00:00 |
06:27:52.97 |
-66:13:46.7 |
HIP 31003 |
19.57 |
| 2026-02-15 12:00 |
06:27:49.26 |
-66:13:17.6 |
HIP 31003 |
19.57 |
| 2026-02-16 00:00 |
06:27:45.59 |
-66:12:48.4 |
HIP 31003 |
19.58 |
| 2026-02-16 12:00 |
06:27:41.97 |
-66:12:19.0 |
HIP 31003 |
19.60 |
| 2026-02-17 00:00 |
06:27:38.39 |
-66:11:49.3 |
HIP 31003 |
19.64 |
| 2026-02-17 12:00 |
06:27:34.85 |
-66:11:19.5 |
HIP 31003 |
19.69 |
| 2026-02-18 00:00 |
06:27:31.36 |
-66:10:49.4 |
HIP 31003 |
19.76 |
| 2026-02-18 12:00 |
06:27:27.91 |
-66:10:19.2 |
HIP 31003 |
19.83 |
| 2026-02-19 00:00 |
06:27:24.51 |
-66:09:48.7 |
HIP 31003 |
19.93 |
| 2026-02-19 12:00 |
06:27:21.15 |
-66:09:18.1 |
HIP 31003 |
20.03 |
| 2026-02-20 00:00 |
06:27:17.83 |
-66:08:47.2 |
HIP 31003 |
20.15 |
| 2026-02-20 12:00 |
06:27:14.57 |
-66:08:16.2 |
HIP 31003 |
20.28 |
| 2026-02-21 00:00 |
06:27:11.35 |
-66:07:45.0 |
HIP 31003 |
20.42 |
| 2026-02-21 12:00 |
06:27:08.17 |
-66:07:13.7 |
HIP 31003 |
20.57 |
| 2026-02-22 00:00 |
06:27:05.04 |
-66:06:42.1 |
HIP 31003 |
20.74 |
| 2026-02-22 12:00 |
06:27:01.96 |
-66:06:10.4 |
HIP 31003 |
20.92 |
| 2026-02-23 00:00 |
06:26:58.93 |
-66:05:38.5 |
HIP 31003 |
21.11 |
| 2026-02-23 12:00 |
06:26:55.94 |
-66:05:06.4 |
HIP 31003 |
21.31 |
| 2026-02-24 00:00 |
06:26:53.00 |
-66:04:34.1 |
HIP 31003 |
21.52 |