| Parameter |
Value |
| Designation |
C/1898 R1 (Perrine-Chofardet) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1898-10-21T00:56:12.053760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:56Z |
| Obs used |
71 |
| NEO |
- |
| M1 |
7.500 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1898-09-21.0000000 |
| e |
1.00003407 |
| q (au) |
0.420481 |
| a (au) |
-12342.273054 |
| i (deg) |
28.858333 |
| Ω (om, deg) |
36.291475 |
| ω (w, deg) |
162.363692 |
| M (ma, deg) |
-0.000022 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
01:13:58.76 |
-04:16:08.3 |
HIP 5620 |
30.47 |
| 2026-05-12 12:00 |
01:13:59.43 |
-04:16:05.6 |
HIP 5620 |
30.63 |
| 2026-05-13 00:00 |
01:14:00.09 |
-04:16:03.0 |
HIP 5620 |
30.80 |
| 2026-05-13 12:00 |
01:14:00.75 |
-04:16:00.4 |
HIP 5620 |
30.97 |
| 2026-05-14 00:00 |
01:14:01.40 |
-04:15:57.8 |
HIP 5620 |
31.13 |
| 2026-05-14 12:00 |
01:14:02.05 |
-04:15:55.3 |
HIP 5620 |
31.30 |
| 2026-05-15 00:00 |
01:14:02.70 |
-04:15:52.8 |
HIP 5620 |
31.46 |
| 2026-05-15 12:00 |
01:14:03.34 |
-04:15:50.4 |
HIP 5620 |
31.62 |
| 2026-05-16 00:00 |
01:14:03.98 |
-04:15:48.0 |
HIP 5620 |
31.78 |
| 2026-05-16 12:00 |
01:14:04.62 |
-04:15:45.6 |
HIP 5620 |
31.95 |
| 2026-05-17 00:00 |
01:14:05.25 |
-04:15:43.3 |
HIP 5845 |
31.99 |
| 2026-05-17 12:00 |
01:14:05.88 |
-04:15:41.0 |
HIP 5845 |
31.89 |
| 2026-05-18 00:00 |
01:14:06.51 |
-04:15:38.7 |
HIP 5845 |
31.79 |
| 2026-05-18 12:00 |
01:14:07.13 |
-04:15:36.5 |
HIP 5845 |
31.69 |
| 2026-05-19 00:00 |
01:14:07.74 |
-04:15:34.4 |
HIP 5845 |
31.60 |
| 2026-05-19 12:00 |
01:14:08.36 |
-04:15:32.2 |
HIP 5845 |
31.50 |
| 2026-05-20 00:00 |
01:14:08.97 |
-04:15:30.2 |
HIP 5845 |
31.41 |
| 2026-05-20 12:00 |
01:14:09.57 |
-04:15:28.1 |
HIP 5845 |
31.31 |
| 2026-05-21 00:00 |
01:14:10.17 |
-04:15:26.1 |
HIP 5845 |
31.22 |
| 2026-05-21 12:00 |
01:14:10.77 |
-04:15:24.2 |
HIP 5845 |
31.13 |
| 2026-05-22 00:00 |
01:14:11.36 |
-04:15:22.2 |
HIP 5845 |
31.05 |
| 2026-05-22 12:00 |
01:14:11.95 |
-04:15:20.4 |
HIP 5845 |
30.96 |
| 2026-05-23 00:00 |
01:14:12.54 |
-04:15:18.5 |
HIP 5845 |
30.87 |
| 2026-05-23 12:00 |
01:14:13.12 |
-04:15:16.8 |
HIP 5845 |
30.79 |
| 2026-05-24 00:00 |
01:14:13.69 |
-04:15:15.0 |
HIP 5845 |
30.71 |
| 2026-05-24 12:00 |
01:14:14.26 |
-04:15:13.3 |
HIP 5845 |
30.63 |
| 2026-05-25 00:00 |
01:14:14.83 |
-04:15:11.6 |
HIP 5845 |
30.55 |
| 2026-05-25 12:00 |
01:14:15.39 |
-04:15:10.0 |
HIP 5845 |
30.47 |
| 2026-05-26 00:00 |
01:14:15.95 |
-04:15:08.4 |
HIP 5845 |
30.40 |
| 2026-05-26 12:00 |
01:14:16.50 |
-04:15:06.9 |
HIP 5845 |
30.32 |
| 2026-05-27 00:00 |
01:14:17.05 |
-04:15:05.4 |
HIP 5845 |
30.25 |
| 2026-05-27 12:00 |
01:14:17.60 |
-04:15:04.0 |
HIP 5845 |
30.18 |
| 2026-05-28 00:00 |
01:14:18.14 |
-04:15:02.6 |
HIP 5845 |
30.11 |
| 2026-05-28 12:00 |
01:14:18.67 |
-04:15:01.2 |
HIP 5845 |
30.04 |
| 2026-05-29 00:00 |
01:14:19.20 |
-04:14:59.9 |
HIP 5845 |
29.98 |
| 2026-05-29 12:00 |
01:14:19.73 |
-04:14:58.6 |
HIP 5845 |
29.91 |
| 2026-05-30 00:00 |
01:14:20.25 |
-04:14:57.4 |
HIP 5845 |
29.85 |
| 2026-05-30 12:00 |
01:14:20.77 |
-04:14:56.2 |
HIP 5845 |
29.78 |
| 2026-05-31 00:00 |
01:14:21.28 |
-04:14:55.0 |
HIP 5845 |
29.72 |
| 2026-05-31 12:00 |
01:14:21.78 |
-04:14:53.9 |
HIP 5845 |
29.67 |
| 2026-06-01 00:00 |
01:14:22.29 |
-04:14:52.9 |
HIP 5845 |
29.61 |
| 2026-06-01 12:00 |
01:14:22.78 |
-04:14:51.8 |
HIP 5845 |
29.55 |
| 2026-06-02 00:00 |
01:14:23.27 |
-04:14:50.9 |
HIP 5845 |
29.50 |