C/1898 R1 (Perrine-Chofardet)
| 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) |
| 2026-02-03 00:00 |
01:11:49.71 |
-04:31:27.1 |
HIP 5620 |
5.17 |
| 2026-02-03 12:00 |
01:11:50.04 |
-04:31:22.7 |
HIP 5620 |
5.07 |
| 2026-02-04 00:00 |
01:11:50.37 |
-04:31:18.2 |
HIP 5620 |
4.97 |
| 2026-02-04 12:00 |
01:11:50.71 |
-04:31:13.8 |
HIP 5620 |
4.86 |
| 2026-02-05 00:00 |
01:11:51.06 |
-04:31:09.3 |
HIP 5620 |
4.75 |
| 2026-02-05 12:00 |
01:11:51.41 |
-04:31:04.7 |
HIP 5620 |
4.65 |
| 2026-02-06 00:00 |
01:11:51.76 |
-04:31:00.2 |
HIP 5620 |
4.54 |
| 2026-02-06 12:00 |
01:11:52.13 |
-04:30:55.6 |
HIP 5620 |
4.43 |
| 2026-02-07 00:00 |
01:11:52.49 |
-04:30:51.0 |
HIP 5620 |
4.32 |
| 2026-02-07 12:00 |
01:11:52.87 |
-04:30:46.3 |
HIP 5620 |
4.20 |
| 2026-02-08 00:00 |
01:11:53.25 |
-04:30:41.7 |
HIP 5620 |
4.09 |
| 2026-02-08 12:00 |
01:11:53.64 |
-04:30:37.0 |
HIP 5620 |
3.98 |
| 2026-02-09 00:00 |
01:11:54.03 |
-04:30:32.3 |
HIP 5620 |
3.86 |
| 2026-02-09 12:00 |
01:11:54.43 |
-04:30:27.6 |
HIP 5620 |
3.74 |
| 2026-02-10 00:00 |
01:11:54.83 |
-04:30:22.8 |
HIP 5620 |
3.63 |
| 2026-02-10 12:00 |
01:11:55.24 |
-04:30:18.0 |
HIP 5620 |
3.51 |
| 2026-02-11 00:00 |
01:11:55.66 |
-04:30:13.2 |
HIP 5620 |
3.39 |
| 2026-02-11 12:00 |
01:11:56.08 |
-04:30:08.4 |
HIP 5620 |
3.27 |
| 2026-02-12 00:00 |
01:11:56.50 |
-04:30:03.6 |
HIP 5620 |
3.15 |
| 2026-02-12 12:00 |
01:11:56.94 |
-04:29:58.7 |
HIP 5620 |
3.03 |
| 2026-02-13 00:00 |
01:11:57.38 |
-04:29:53.8 |
HIP 5620 |
2.91 |
| 2026-02-13 12:00 |
01:11:57.82 |
-04:29:48.9 |
HIP 5620 |
2.80 |
| 2026-02-14 00:00 |
01:11:58.27 |
-04:29:44.0 |
HIP 5620 |
2.68 |
| 2026-02-14 12:00 |
01:11:58.73 |
-04:29:39.1 |
HIP 5620 |
2.56 |
| 2026-02-15 00:00 |
01:11:59.19 |
-04:29:34.1 |
HIP 5620 |
2.44 |
| 2026-02-15 12:00 |
01:11:59.65 |
-04:29:29.1 |
HIP 5620 |
2.32 |
| 2026-02-16 00:00 |
01:12:00.13 |
-04:29:24.1 |
HIP 5620 |
2.21 |
| 2026-02-16 12:00 |
01:12:00.60 |
-04:29:19.1 |
HIP 5620 |
2.10 |
| 2026-02-17 00:00 |
01:12:01.09 |
-04:29:14.1 |
HIP 5620 |
1.99 |
| 2026-02-17 12:00 |
01:12:01.57 |
-04:29:09.0 |
HIP 5620 |
1.88 |
| 2026-02-18 00:00 |
01:12:02.07 |
-04:29:04.0 |
HIP 5620 |
1.78 |
| 2026-02-18 12:00 |
01:12:02.56 |
-04:28:58.9 |
HIP 5620 |
1.69 |
| 2026-02-19 00:00 |
01:12:03.07 |
-04:28:53.8 |
HIP 5620 |
1.60 |
| 2026-02-19 12:00 |
01:12:03.58 |
-04:28:48.6 |
HIP 5620 |
1.52 |
| 2026-02-20 00:00 |
01:12:04.09 |
-04:28:43.5 |
HIP 5620 |
1.46 |
| 2026-02-20 12:00 |
01:12:04.61 |
-04:28:38.4 |
HIP 5620 |
1.40 |
| 2026-02-21 00:00 |
01:12:05.13 |
-04:28:33.2 |
HIP 5620 |
1.37 |
| 2026-02-21 12:00 |
01:12:05.66 |
-04:28:28.0 |
HIP 5620 |
1.34 |
| 2026-02-22 00:00 |
01:12:06.20 |
-04:28:22.9 |
HIP 5620 |
1.34 |
| 2026-02-22 12:00 |
01:12:06.74 |
-04:28:17.7 |
HIP 5620 |
1.35 |
| 2026-02-23 00:00 |
01:12:07.28 |
-04:28:12.4 |
HIP 5620 |
1.39 |
| 2026-02-23 12:00 |
01:12:07.83 |
-04:28:07.2 |
HIP 5620 |
1.44 |
| 2026-02-24 00:00 |
01:12:08.38 |
-04:28:02.0 |
HIP 5620 |
1.50 |