| Parameter |
Value |
| Designation |
C/1977 R1 (Kohler) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1977-11-10T13:40:46.989120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:27Z |
| Obs used |
421 |
| NEO |
- |
| M1 |
7.300 |
| K1 |
13.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1977-11-01.0000000 |
| e |
0.99954935 |
| q (au) |
0.990576 |
| a (au) |
2198.096723 |
| i (deg) |
48.711865 |
| Ω (om, deg) |
182.522684 |
| ω (w, deg) |
163.486616 |
| M (ma, deg) |
359.999908 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.933 + 5.854\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.933 |
| n |
5.854 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.800 |
| δ90 |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
10:18:03.66 |
-13:08:33.0 |
HIP 50476 |
10.89 |
| 2026-03-26 12:00 |
10:18:02.35 |
-13:08:20.7 |
HIP 50476 |
11.22 |
| 2026-03-27 00:00 |
10:18:01.05 |
-13:08:08.4 |
HIP 50476 |
11.55 |
| 2026-03-27 12:00 |
10:17:59.76 |
-13:07:56.0 |
HIP 50476 |
11.88 |
| 2026-03-28 00:00 |
10:17:58.48 |
-13:07:43.6 |
HIP 50476 |
12.21 |
| 2026-03-28 12:00 |
10:17:57.20 |
-13:07:31.2 |
HIP 50476 |
12.55 |
| 2026-03-29 00:00 |
10:17:55.93 |
-13:07:18.8 |
HIP 50476 |
12.89 |
| 2026-03-29 12:00 |
10:17:54.67 |
-13:07:06.3 |
HIP 50476 |
13.23 |
| 2026-03-30 00:00 |
10:17:53.42 |
-13:06:53.8 |
HIP 50476 |
13.57 |
| 2026-03-30 12:00 |
10:17:52.18 |
-13:06:41.2 |
HIP 50476 |
13.91 |
| 2026-03-31 00:00 |
10:17:50.94 |
-13:06:28.7 |
HIP 50476 |
14.25 |
| 2026-03-31 12:00 |
10:17:49.71 |
-13:06:16.1 |
HIP 50476 |
14.59 |
| 2026-04-01 00:00 |
10:17:48.49 |
-13:06:03.5 |
HIP 50476 |
14.93 |
| 2026-04-01 12:00 |
10:17:47.28 |
-13:05:50.9 |
HIP 50344 |
14.71 |
| 2026-04-02 00:00 |
10:17:46.08 |
-13:05:38.2 |
HIP 50344 |
14.42 |
| 2026-04-02 12:00 |
10:17:44.89 |
-13:05:25.6 |
HIP 50344 |
14.14 |
| 2026-04-03 00:00 |
10:17:43.71 |
-13:05:12.9 |
HIP 50344 |
13.86 |
| 2026-04-03 12:00 |
10:17:42.53 |
-13:05:00.2 |
HIP 50344 |
13.59 |
| 2026-04-04 00:00 |
10:17:41.37 |
-13:04:47.5 |
HIP 50344 |
13.32 |
| 2026-04-04 12:00 |
10:17:40.21 |
-13:04:34.7 |
HIP 50344 |
13.07 |
| 2026-04-05 00:00 |
10:17:39.06 |
-13:04:22.0 |
HIP 50344 |
12.81 |
| 2026-04-05 12:00 |
10:17:37.92 |
-13:04:09.2 |
HIP 50344 |
12.57 |
| 2026-04-06 00:00 |
10:17:36.79 |
-13:03:56.5 |
HIP 50344 |
12.33 |
| 2026-04-06 12:00 |
10:17:35.67 |
-13:03:43.7 |
HIP 50344 |
12.10 |
| 2026-04-07 00:00 |
10:17:34.56 |
-13:03:30.9 |
HIP 50344 |
11.87 |
| 2026-04-07 12:00 |
10:17:33.46 |
-13:03:18.1 |
HIP 50344 |
11.66 |
| 2026-04-08 00:00 |
10:17:32.37 |
-13:03:05.2 |
HIP 50344 |
11.45 |
| 2026-04-08 12:00 |
10:17:31.29 |
-13:02:52.4 |
HIP 50344 |
11.25 |
| 2026-04-09 00:00 |
10:17:30.22 |
-13:02:39.6 |
HIP 50344 |
11.07 |
| 2026-04-09 12:00 |
10:17:29.16 |
-13:02:26.7 |
HIP 50344 |
10.89 |
| 2026-04-10 00:00 |
10:17:28.11 |
-13:02:13.9 |
HIP 50344 |
10.72 |
| 2026-04-10 12:00 |
10:17:27.06 |
-13:02:01.0 |
HIP 50344 |
10.56 |
| 2026-04-11 00:00 |
10:17:26.03 |
-13:01:48.1 |
HIP 50344 |
10.41 |
| 2026-04-11 12:00 |
10:17:25.01 |
-13:01:35.3 |
HIP 50344 |
10.27 |
| 2026-04-12 00:00 |
10:17:24.00 |
-13:01:22.4 |
HIP 50344 |
10.15 |
| 2026-04-12 12:00 |
10:17:23.00 |
-13:01:09.6 |
HIP 50344 |
10.03 |
| 2026-04-13 00:00 |
10:17:22.01 |
-13:00:56.7 |
HIP 50344 |
9.93 |
| 2026-04-13 12:00 |
10:17:21.03 |
-13:00:43.8 |
HIP 50344 |
9.83 |
| 2026-04-14 00:00 |
10:17:20.06 |
-13:00:31.0 |
HIP 50344 |
9.75 |
| 2026-04-14 12:00 |
10:17:19.10 |
-13:00:18.1 |
HIP 50344 |
9.68 |
| 2026-04-15 00:00 |
10:17:18.16 |
-13:00:05.2 |
HIP 50344 |
9.63 |
| 2026-04-15 12:00 |
10:17:17.22 |
-12:59:52.4 |
HIP 50344 |
9.58 |
| 2026-04-16 00:00 |
10:17:16.29 |
-12:59:39.5 |
HIP 50344 |
9.55 |