| 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) |
| 2026-03-26 00:00 |
01:12:48.48 |
-04:22:40.9 |
HIP 5620 |
11.99 |
| 2026-03-26 12:00 |
01:12:49.23 |
-04:22:35.7 |
HIP 5620 |
12.20 |
| 2026-03-27 00:00 |
01:12:49.99 |
-04:22:30.5 |
HIP 5620 |
12.40 |
| 2026-03-27 12:00 |
01:12:50.74 |
-04:22:25.3 |
HIP 5620 |
12.60 |
| 2026-03-28 00:00 |
01:12:51.50 |
-04:22:20.1 |
HIP 5620 |
12.81 |
| 2026-03-28 12:00 |
01:12:52.25 |
-04:22:14.9 |
HIP 5620 |
13.01 |
| 2026-03-29 00:00 |
01:12:53.01 |
-04:22:09.8 |
HIP 5620 |
13.22 |
| 2026-03-29 12:00 |
01:12:53.77 |
-04:22:04.6 |
HIP 5620 |
13.42 |
| 2026-03-30 00:00 |
01:12:54.53 |
-04:21:59.5 |
HIP 5620 |
13.63 |
| 2026-03-30 12:00 |
01:12:55.30 |
-04:21:54.4 |
HIP 5620 |
13.83 |
| 2026-03-31 00:00 |
01:12:56.06 |
-04:21:49.3 |
HIP 5620 |
14.04 |
| 2026-03-31 12:00 |
01:12:56.82 |
-04:21:44.2 |
HIP 5620 |
14.25 |
| 2026-04-01 00:00 |
01:12:57.59 |
-04:21:39.2 |
HIP 5620 |
14.45 |
| 2026-04-01 12:00 |
01:12:58.36 |
-04:21:34.1 |
HIP 5620 |
14.66 |
| 2026-04-02 00:00 |
01:12:59.12 |
-04:21:29.1 |
HIP 5620 |
14.86 |
| 2026-04-02 12:00 |
01:12:59.89 |
-04:21:24.1 |
HIP 5620 |
15.07 |
| 2026-04-03 00:00 |
01:13:00.66 |
-04:21:19.1 |
HIP 5620 |
15.28 |
| 2026-04-03 12:00 |
01:13:01.43 |
-04:21:14.1 |
HIP 5620 |
15.48 |
| 2026-04-04 00:00 |
01:13:02.20 |
-04:21:09.1 |
HIP 5620 |
15.69 |
| 2026-04-04 12:00 |
01:13:02.98 |
-04:21:04.2 |
HIP 5620 |
15.90 |
| 2026-04-05 00:00 |
01:13:03.75 |
-04:20:59.3 |
HIP 5620 |
16.10 |
| 2026-04-05 12:00 |
01:13:04.52 |
-04:20:54.4 |
HIP 5620 |
16.31 |
| 2026-04-06 00:00 |
01:13:05.29 |
-04:20:49.5 |
HIP 5620 |
16.52 |
| 2026-04-06 12:00 |
01:13:06.07 |
-04:20:44.6 |
HIP 5620 |
16.72 |
| 2026-04-07 00:00 |
01:13:06.84 |
-04:20:39.8 |
HIP 5620 |
16.93 |
| 2026-04-07 12:00 |
01:13:07.62 |
-04:20:34.9 |
HIP 5620 |
17.14 |
| 2026-04-08 00:00 |
01:13:08.39 |
-04:20:30.1 |
HIP 5620 |
17.34 |
| 2026-04-08 12:00 |
01:13:09.17 |
-04:20:25.3 |
HIP 5620 |
17.55 |
| 2026-04-09 00:00 |
01:13:09.94 |
-04:20:20.6 |
HIP 5620 |
17.76 |
| 2026-04-09 12:00 |
01:13:10.72 |
-04:20:15.8 |
HIP 5620 |
17.96 |
| 2026-04-10 00:00 |
01:13:11.49 |
-04:20:11.1 |
HIP 5620 |
18.17 |
| 2026-04-10 12:00 |
01:13:12.27 |
-04:20:06.4 |
HIP 5620 |
18.37 |
| 2026-04-11 00:00 |
01:13:13.04 |
-04:20:01.7 |
HIP 5620 |
18.58 |
| 2026-04-11 12:00 |
01:13:13.82 |
-04:19:57.1 |
HIP 5620 |
18.79 |
| 2026-04-12 00:00 |
01:13:14.60 |
-04:19:52.5 |
HIP 5620 |
18.99 |
| 2026-04-12 12:00 |
01:13:15.37 |
-04:19:47.8 |
HIP 5620 |
19.20 |
| 2026-04-13 00:00 |
01:13:16.15 |
-04:19:43.3 |
HIP 5620 |
19.40 |
| 2026-04-13 12:00 |
01:13:16.92 |
-04:19:38.7 |
HIP 5620 |
19.61 |
| 2026-04-14 00:00 |
01:13:17.69 |
-04:19:34.2 |
HIP 5620 |
19.81 |
| 2026-04-14 12:00 |
01:13:18.47 |
-04:19:29.7 |
HIP 5620 |
20.02 |
| 2026-04-15 00:00 |
01:13:19.24 |
-04:19:25.2 |
HIP 5620 |
20.22 |
| 2026-04-15 12:00 |
01:13:20.01 |
-04:19:20.7 |
HIP 5620 |
20.43 |
| 2026-04-16 00:00 |
01:13:20.79 |
-04:19:16.3 |
HIP 5620 |
20.63 |