| Parameter |
Value |
| Designation |
C/1917 H1 (Schaumasse) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1917-05-18T16:57:51.399360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:02Z |
| Obs used |
45 |
| NEO |
- |
| M1 |
12.000 |
| K1 |
31.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1917-05-25.0000000 |
| e |
1.00006471 |
| q (au) |
0.764170 |
| a (au) |
-11809.001775 |
| i (deg) |
158.739267 |
| Ω (om, deg) |
10.829618 |
| ω (w, deg) |
119.148065 |
| M (ma, deg) |
0.000005 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.089 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.089 |
| n |
6.000 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
1.000 |
| 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) |
| 2026-09-20 00:00 |
05:20:15.08 |
+03:16:47.6 |
HIP 24830 |
16.15 |
| 2026-09-20 12:00 |
05:20:14.96 |
+03:16:42.8 |
HIP 24830 |
16.08 |
| 2026-09-21 00:00 |
05:20:14.82 |
+03:16:37.9 |
HIP 24830 |
16.01 |
| 2026-09-21 12:00 |
05:20:14.69 |
+03:16:33.1 |
HIP 24830 |
15.93 |
| 2026-09-22 00:00 |
05:20:14.54 |
+03:16:28.3 |
HIP 24830 |
15.86 |
| 2026-09-22 12:00 |
05:20:14.38 |
+03:16:23.5 |
HIP 24830 |
15.78 |
| 2026-09-23 00:00 |
05:20:14.22 |
+03:16:18.6 |
HIP 24830 |
15.70 |
| 2026-09-23 12:00 |
05:20:14.05 |
+03:16:13.8 |
HIP 24830 |
15.62 |
| 2026-09-24 00:00 |
05:20:13.87 |
+03:16:09.0 |
HIP 24830 |
15.54 |
| 2026-09-24 12:00 |
05:20:13.68 |
+03:16:04.1 |
HIP 24830 |
15.45 |
| 2026-09-25 00:00 |
05:20:13.49 |
+03:15:59.3 |
HIP 24830 |
15.37 |
| 2026-09-25 12:00 |
05:20:13.29 |
+03:15:54.5 |
HIP 24830 |
15.28 |
| 2026-09-26 00:00 |
05:20:13.08 |
+03:15:49.6 |
HIP 24830 |
15.19 |
| 2026-09-26 12:00 |
05:20:12.86 |
+03:15:44.8 |
HIP 24830 |
15.10 |
| 2026-09-27 00:00 |
05:20:12.63 |
+03:15:40.0 |
HIP 24830 |
15.01 |
| 2026-09-27 12:00 |
05:20:12.40 |
+03:15:35.1 |
HIP 24830 |
14.92 |
| 2026-09-28 00:00 |
05:20:12.16 |
+03:15:30.3 |
HIP 24830 |
14.82 |
| 2026-09-28 12:00 |
05:20:11.91 |
+03:15:25.4 |
HIP 24830 |
14.73 |
| 2026-09-29 00:00 |
05:20:11.65 |
+03:15:20.6 |
HIP 24830 |
14.63 |
| 2026-09-29 12:00 |
05:20:11.38 |
+03:15:15.8 |
HIP 24830 |
14.53 |
| 2026-09-30 00:00 |
05:20:11.11 |
+03:15:11.0 |
HIP 24830 |
14.43 |
| 2026-09-30 12:00 |
05:20:10.83 |
+03:15:06.1 |
HIP 24830 |
14.33 |
| 2026-10-01 00:00 |
05:20:10.54 |
+03:15:01.3 |
HIP 24830 |
14.22 |
| 2026-10-01 12:00 |
05:20:10.25 |
+03:14:56.5 |
HIP 24830 |
14.12 |
| 2026-10-02 00:00 |
05:20:09.94 |
+03:14:51.7 |
HIP 24830 |
14.01 |
| 2026-10-02 12:00 |
05:20:09.63 |
+03:14:46.9 |
HIP 24830 |
13.90 |
| 2026-10-03 00:00 |
05:20:09.31 |
+03:14:42.1 |
HIP 24830 |
13.79 |
| 2026-10-03 12:00 |
05:20:08.99 |
+03:14:37.3 |
HIP 24830 |
13.68 |
| 2026-10-04 00:00 |
05:20:08.65 |
+03:14:32.5 |
HIP 24830 |
13.57 |
| 2026-10-04 12:00 |
05:20:08.31 |
+03:14:27.7 |
HIP 24830 |
13.45 |
| 2026-10-05 00:00 |
05:20:07.96 |
+03:14:22.9 |
HIP 24830 |
13.33 |
| 2026-10-05 12:00 |
05:20:07.60 |
+03:14:18.1 |
HIP 24830 |
13.22 |
| 2026-10-06 00:00 |
05:20:07.24 |
+03:14:13.4 |
HIP 24830 |
13.10 |
| 2026-10-06 12:00 |
05:20:06.87 |
+03:14:08.6 |
HIP 24830 |
12.98 |
| 2026-10-07 00:00 |
05:20:06.49 |
+03:14:03.8 |
HIP 24830 |
12.86 |
| 2026-10-07 12:00 |
05:20:06.10 |
+03:13:59.1 |
HIP 24830 |
12.73 |
| 2026-10-08 00:00 |
05:20:05.70 |
+03:13:54.4 |
HIP 24830 |
12.61 |
| 2026-10-08 12:00 |
05:20:05.30 |
+03:13:49.6 |
HIP 24830 |
12.48 |
| 2026-10-09 00:00 |
05:20:04.89 |
+03:13:44.9 |
HIP 24830 |
12.35 |
| 2026-10-09 12:00 |
05:20:04.47 |
+03:13:40.2 |
HIP 24830 |
12.22 |
| 2026-10-10 00:00 |
05:20:04.05 |
+03:13:35.5 |
HIP 24830 |
12.09 |
| 2026-10-10 12:00 |
05:20:03.62 |
+03:13:30.8 |
HIP 24830 |
11.96 |
| 2026-10-11 00:00 |
05:20:03.18 |
+03:13:26.1 |
HIP 24830 |
11.82 |