| Parameter |
Value |
| Designation |
C/2002 Y1 (Juels-Holvorcem) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2003-04-13T05:57:14.526720Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:25Z |
| Obs used |
760 |
| NEO |
- |
| M1 |
9.500 |
| K1 |
16.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2003-02-10.0000000 |
| e |
0.99715189 |
| q (au) |
0.713810 |
| a (au) |
250.625452 |
| i (deg) |
103.781543 |
| Ω (om, deg) |
166.220096 |
| ω (w, deg) |
128.815568 |
| M (ma, deg) |
359.984537 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.760 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.760 |
| n |
6.000 |
| 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 |
| 2002-01-12 |
2003-01-11 |
-33.2594 |
+10.778 |
| 2003-01-11 |
2003-04-12 |
+5.2439 |
+0.172 |
| 2003-04-13 |
2004-01-23 |
-2.2806 |
-1.257 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
09:59:46.82 |
-59:21:59.5 |
HIP 48996 |
5.55 |
| 2026-03-26 12:00 |
09:59:42.83 |
-59:21:31.5 |
HIP 48996 |
5.10 |
| 2026-03-27 00:00 |
09:59:38.87 |
-59:21:03.2 |
HIP 48996 |
4.69 |
| 2026-03-27 12:00 |
09:59:34.94 |
-59:20:34.8 |
HIP 48996 |
4.36 |
| 2026-03-28 00:00 |
09:59:31.04 |
-59:20:06.0 |
HIP 48996 |
4.10 |
| 2026-03-28 12:00 |
09:59:27.16 |
-59:19:37.1 |
HIP 48996 |
3.95 |
| 2026-03-29 00:00 |
09:59:23.32 |
-59:19:07.9 |
HIP 48993 |
3.89 |
| 2026-03-29 12:00 |
09:59:19.51 |
-59:18:38.5 |
HIP 48993 |
3.92 |
| 2026-03-30 00:00 |
09:59:15.73 |
-59:18:08.8 |
HIP 48993 |
4.06 |
| 2026-03-30 12:00 |
09:59:11.98 |
-59:17:38.9 |
HIP 48993 |
4.31 |
| 2026-03-31 00:00 |
09:59:08.26 |
-59:17:08.8 |
HIP 48993 |
4.64 |
| 2026-03-31 12:00 |
09:59:04.57 |
-59:16:38.5 |
HIP 48993 |
5.05 |
| 2026-04-01 00:00 |
09:59:00.91 |
-59:16:07.9 |
HIP 48993 |
5.50 |
| 2026-04-01 12:00 |
09:58:57.29 |
-59:15:37.1 |
HIP 48993 |
6.00 |
| 2026-04-02 00:00 |
09:58:53.69 |
-59:15:06.1 |
HIP 48993 |
6.53 |
| 2026-04-02 12:00 |
09:58:50.13 |
-59:14:34.9 |
HIP 48993 |
7.09 |
| 2026-04-03 00:00 |
09:58:46.60 |
-59:14:03.5 |
HIP 48993 |
7.66 |
| 2026-04-03 12:00 |
09:58:43.10 |
-59:13:31.8 |
HIP 48993 |
8.25 |
| 2026-04-04 00:00 |
09:58:39.64 |
-59:13:00.0 |
HIP 48993 |
8.85 |
| 2026-04-04 12:00 |
09:58:36.21 |
-59:12:27.9 |
HIP 48993 |
9.47 |
| 2026-04-05 00:00 |
09:58:32.81 |
-59:11:55.7 |
HIP 48993 |
10.09 |
| 2026-04-05 12:00 |
09:58:29.45 |
-59:11:23.2 |
HIP 48993 |
10.71 |
| 2026-04-06 00:00 |
09:58:26.12 |
-59:10:50.6 |
HIP 48993 |
11.34 |
| 2026-04-06 12:00 |
09:58:22.82 |
-59:10:17.7 |
HIP 48993 |
11.98 |
| 2026-04-07 00:00 |
09:58:19.56 |
-59:09:44.7 |
HIP 48993 |
12.62 |
| 2026-04-07 12:00 |
09:58:16.33 |
-59:09:11.4 |
HIP 48993 |
13.27 |
| 2026-04-08 00:00 |
09:58:13.14 |
-59:08:38.0 |
HIP 48993 |
13.91 |
| 2026-04-08 12:00 |
09:58:09.98 |
-59:08:04.4 |
HIP 48993 |
14.56 |
| 2026-04-09 00:00 |
09:58:06.86 |
-59:07:30.6 |
HIP 48993 |
15.21 |
| 2026-04-09 12:00 |
09:58:03.77 |
-59:06:56.7 |
HIP 48993 |
15.86 |
| 2026-04-10 00:00 |
09:58:00.72 |
-59:06:22.5 |
HIP 48993 |
16.52 |
| 2026-04-10 12:00 |
09:57:57.70 |
-59:05:48.2 |
HIP 48993 |
17.17 |
| 2026-04-11 00:00 |
09:57:54.72 |
-59:05:13.7 |
HIP 48679 |
17.07 |
| 2026-04-11 12:00 |
09:57:51.78 |
-59:04:39.0 |
HIP 48679 |
16.75 |
| 2026-04-12 00:00 |
09:57:48.87 |
-59:04:04.2 |
HIP 48679 |
16.45 |
| 2026-04-12 12:00 |
09:57:46.00 |
-59:03:29.2 |
HIP 48679 |
16.18 |
| 2026-04-13 00:00 |
09:57:43.16 |
-59:02:54.1 |
HIP 48679 |
15.95 |
| 2026-04-13 12:00 |
09:57:40.37 |
-59:02:18.7 |
HIP 48679 |
15.74 |
| 2026-04-14 00:00 |
09:57:37.60 |
-59:01:43.3 |
HIP 48679 |
15.57 |
| 2026-04-14 12:00 |
09:57:34.88 |
-59:01:07.7 |
HIP 48679 |
15.43 |
| 2026-04-15 00:00 |
09:57:32.20 |
-59:00:31.9 |
HIP 48679 |
15.33 |
| 2026-04-15 12:00 |
09:57:29.55 |
-58:59:56.0 |
HIP 48679 |
15.26 |
| 2026-04-16 00:00 |
09:57:26.94 |
-58:59:19.9 |
HIP 48679 |
15.23 |