| 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 |
10.000 |
| 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) |
| 2026-05-12 00:00 |
12:40:51.93 |
-37:10:16.5 |
HIP 61775 |
16.05 |
| 2026-05-12 12:00 |
12:40:49.72 |
-37:09:54.0 |
HIP 61775 |
15.82 |
| 2026-05-13 00:00 |
12:40:47.52 |
-37:09:31.5 |
HIP 61775 |
15.62 |
| 2026-05-13 12:00 |
12:40:45.34 |
-37:09:08.9 |
HIP 61775 |
15.43 |
| 2026-05-14 00:00 |
12:40:43.18 |
-37:08:46.3 |
HIP 61775 |
15.27 |
| 2026-05-14 12:00 |
12:40:41.03 |
-37:08:23.6 |
HIP 61775 |
15.13 |
| 2026-05-15 00:00 |
12:40:38.90 |
-37:08:00.9 |
HIP 61775 |
15.02 |
| 2026-05-15 12:00 |
12:40:36.79 |
-37:07:38.1 |
HIP 61775 |
14.93 |
| 2026-05-16 00:00 |
12:40:34.69 |
-37:07:15.3 |
HIP 61775 |
14.86 |
| 2026-05-16 12:00 |
12:40:32.61 |
-37:06:52.4 |
HIP 61775 |
14.82 |
| 2026-05-17 00:00 |
12:40:30.55 |
-37:06:29.5 |
HIP 61775 |
14.80 |
| 2026-05-17 12:00 |
12:40:28.51 |
-37:06:06.5 |
HIP 61775 |
14.81 |
| 2026-05-18 00:00 |
12:40:26.48 |
-37:05:43.5 |
HIP 61775 |
14.84 |
| 2026-05-18 12:00 |
12:40:24.47 |
-37:05:20.4 |
HIP 61775 |
14.89 |
| 2026-05-19 00:00 |
12:40:22.48 |
-37:04:57.3 |
HIP 61775 |
14.96 |
| 2026-05-19 12:00 |
12:40:20.50 |
-37:04:34.2 |
HIP 61775 |
15.06 |
| 2026-05-20 00:00 |
12:40:18.55 |
-37:04:11.0 |
HIP 61775 |
15.18 |
| 2026-05-20 12:00 |
12:40:16.61 |
-37:03:47.8 |
HIP 61775 |
15.32 |
| 2026-05-21 00:00 |
12:40:14.69 |
-37:03:24.6 |
HIP 61775 |
15.48 |
| 2026-05-21 12:00 |
12:40:12.79 |
-37:03:01.4 |
HIP 61775 |
15.66 |
| 2026-05-22 00:00 |
12:40:10.91 |
-37:02:38.1 |
HIP 61775 |
15.86 |
| 2026-05-22 12:00 |
12:40:09.04 |
-37:02:14.8 |
HIP 61775 |
16.08 |
| 2026-05-23 00:00 |
12:40:07.20 |
-37:01:51.4 |
HIP 61775 |
16.31 |
| 2026-05-23 12:00 |
12:40:05.37 |
-37:01:28.1 |
HIP 61775 |
16.56 |
| 2026-05-24 00:00 |
12:40:03.56 |
-37:01:04.7 |
HIP 61775 |
16.82 |
| 2026-05-24 12:00 |
12:40:01.78 |
-37:00:41.3 |
HIP 61775 |
17.09 |
| 2026-05-25 00:00 |
12:40:00.01 |
-37:00:17.9 |
HIP 61775 |
17.38 |
| 2026-05-25 12:00 |
12:39:58.26 |
-36:59:54.5 |
HIP 61775 |
17.68 |
| 2026-05-26 00:00 |
12:39:56.53 |
-36:59:31.0 |
HIP 61775 |
18.00 |
| 2026-05-26 12:00 |
12:39:54.81 |
-36:59:07.6 |
HIP 61775 |
18.32 |
| 2026-05-27 00:00 |
12:39:53.12 |
-36:58:44.1 |
HIP 61775 |
18.65 |
| 2026-05-27 12:00 |
12:39:51.45 |
-36:58:20.7 |
HIP 61775 |
18.99 |
| 2026-05-28 00:00 |
12:39:49.80 |
-36:57:57.2 |
HIP 61775 |
19.34 |
| 2026-05-28 12:00 |
12:39:48.16 |
-36:57:33.7 |
HIP 61683 |
19.13 |
| 2026-05-29 00:00 |
12:39:46.55 |
-36:57:10.2 |
HIP 61683 |
18.63 |
| 2026-05-29 12:00 |
12:39:44.96 |
-36:56:46.8 |
HIP 61683 |
18.12 |
| 2026-05-30 00:00 |
12:39:43.39 |
-36:56:23.3 |
HIP 61683 |
17.62 |
| 2026-05-30 12:00 |
12:39:41.83 |
-36:55:59.8 |
HIP 61683 |
17.13 |
| 2026-05-31 00:00 |
12:39:40.30 |
-36:55:36.3 |
HIP 61683 |
16.63 |
| 2026-05-31 12:00 |
12:39:38.79 |
-36:55:12.8 |
HIP 61683 |
16.14 |
| 2026-06-01 00:00 |
12:39:37.30 |
-36:54:49.4 |
HIP 61683 |
15.66 |
| 2026-06-01 12:00 |
12:39:35.83 |
-36:54:25.9 |
HIP 61683 |
15.17 |
| 2026-06-02 00:00 |
12:39:34.38 |
-36:54:02.5 |
HIP 61683 |
14.69 |