| Parameter |
Value |
| Designation |
C/1996 R1 (Hergenrother-Spahr) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1996-08-28T17:45:00.472320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:49Z |
| Obs used |
321 |
| NEO |
- |
| M1 |
6.300 |
| K1 |
24.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1996-09-28.0000000 |
| e |
0.98558370 |
| q (au) |
1.899198 |
| a (au) |
131.739702 |
| i (deg) |
145.814443 |
| Ω (om, deg) |
149.745053 |
| ω (w, deg) |
139.456909 |
| M (ma, deg) |
0.019724 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.178 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.178 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.991 |
| δ90 |
9.999 |
| 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) |
| 2026-07-29 00:00 |
12:39:13.69 |
-36:17:00.8 |
HIP 61683 |
27.59 |
| 2026-07-29 12:00 |
12:39:14.76 |
-36:16:48.2 |
HIP 61683 |
27.85 |
| 2026-07-30 00:00 |
12:39:15.84 |
-36:16:35.7 |
HIP 61683 |
28.10 |
| 2026-07-30 12:00 |
12:39:16.95 |
-36:16:23.5 |
HIP 61683 |
28.35 |
| 2026-07-31 00:00 |
12:39:18.08 |
-36:16:11.3 |
HIP 61683 |
28.61 |
| 2026-07-31 12:00 |
12:39:19.23 |
-36:15:59.3 |
HIP 61683 |
28.86 |
| 2026-08-01 00:00 |
12:39:20.40 |
-36:15:47.5 |
HIP 61683 |
29.11 |
| 2026-08-01 12:00 |
12:39:21.58 |
-36:15:35.9 |
HIP 61683 |
29.36 |
| 2026-08-02 00:00 |
12:39:22.79 |
-36:15:24.4 |
HIP 61683 |
29.61 |
| 2026-08-02 12:00 |
12:39:24.01 |
-36:15:13.1 |
HIP 61683 |
29.86 |
| 2026-08-03 00:00 |
12:39:25.25 |
-36:15:01.9 |
HIP 61683 |
30.12 |
| 2026-08-03 12:00 |
12:39:26.52 |
-36:14:50.9 |
HIP 61683 |
30.36 |
| 2026-08-04 00:00 |
12:39:27.80 |
-36:14:40.1 |
HIP 61683 |
30.61 |
| 2026-08-04 12:00 |
12:39:29.10 |
-36:14:29.4 |
HIP 61683 |
30.86 |
| 2026-08-05 00:00 |
12:39:30.41 |
-36:14:18.9 |
HIP 61683 |
31.11 |
| 2026-08-05 12:00 |
12:39:31.75 |
-36:14:08.6 |
HIP 61683 |
31.36 |
| 2026-08-06 00:00 |
12:39:33.11 |
-36:13:58.4 |
HIP 61683 |
31.61 |
| 2026-08-06 12:00 |
12:39:34.48 |
-36:13:48.4 |
HIP 61683 |
31.86 |
| 2026-08-07 00:00 |
12:39:35.87 |
-36:13:38.6 |
HIP 61683 |
32.11 |
| 2026-08-07 12:00 |
12:39:37.28 |
-36:13:28.9 |
HIP 61683 |
32.36 |
| 2026-08-08 00:00 |
12:39:38.71 |
-36:13:19.4 |
HIP 61683 |
32.61 |
| 2026-08-08 12:00 |
12:39:40.16 |
-36:13:10.1 |
HIP 61683 |
32.85 |
| 2026-08-09 00:00 |
12:39:41.62 |
-36:13:01.0 |
HIP 61683 |
33.10 |
| 2026-08-09 12:00 |
12:39:43.11 |
-36:12:52.0 |
HIP 61683 |
33.35 |
| 2026-08-10 00:00 |
12:39:44.61 |
-36:12:43.2 |
HIP 61683 |
33.60 |
| 2026-08-10 12:00 |
12:39:46.12 |
-36:12:34.6 |
HIP 61683 |
33.85 |
| 2026-08-11 00:00 |
12:39:47.66 |
-36:12:26.1 |
HIP 61683 |
34.10 |
| 2026-08-11 12:00 |
12:39:49.21 |
-36:12:17.8 |
HIP 61683 |
34.35 |
| 2026-08-12 00:00 |
12:39:50.78 |
-36:12:09.7 |
HIP 61683 |
34.60 |
| 2026-08-12 12:00 |
12:39:52.37 |
-36:12:01.8 |
HIP 61683 |
34.85 |
| 2026-08-13 00:00 |
12:39:53.97 |
-36:11:54.1 |
HIP 61683 |
35.10 |
| 2026-08-13 12:00 |
12:39:55.59 |
-36:11:46.5 |
HIP 61683 |
35.35 |
| 2026-08-14 00:00 |
12:39:57.23 |
-36:11:39.1 |
HIP 61683 |
35.60 |
| 2026-08-14 12:00 |
12:39:58.89 |
-36:11:31.9 |
HIP 61683 |
35.85 |
| 2026-08-15 00:00 |
12:40:00.56 |
-36:11:24.8 |
HIP 61683 |
36.11 |
| 2026-08-15 12:00 |
12:40:02.24 |
-36:11:18.0 |
HIP 61683 |
36.36 |
| 2026-08-16 00:00 |
12:40:03.95 |
-36:11:11.3 |
HIP 61683 |
36.61 |
| 2026-08-16 12:00 |
12:40:05.67 |
-36:11:04.8 |
HIP 61683 |
36.87 |
| 2026-08-17 00:00 |
12:40:07.40 |
-36:10:58.4 |
HIP 61683 |
37.12 |
| 2026-08-17 12:00 |
12:40:09.15 |
-36:10:52.3 |
HIP 61683 |
37.38 |
| 2026-08-18 00:00 |
12:40:10.92 |
-36:10:46.3 |
HIP 61683 |
37.63 |
| 2026-08-18 12:00 |
12:40:12.70 |
-36:10:40.5 |
HIP 62064 |
37.84 |
| 2026-08-19 00:00 |
12:40:14.50 |
-36:10:34.9 |
HIP 62064 |
37.46 |