| 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) |
| 2026-05-12 00:00 |
05:17:34.82 |
+03:23:06.1 |
HIP 24729 |
10.40 |
| 2026-05-12 12:00 |
05:17:35.61 |
+03:23:09.3 |
HIP 24729 |
10.26 |
| 2026-05-13 00:00 |
05:17:36.40 |
+03:23:12.4 |
HIP 24729 |
10.12 |
| 2026-05-13 12:00 |
05:17:37.20 |
+03:23:15.5 |
HIP 24729 |
9.97 |
| 2026-05-14 00:00 |
05:17:38.01 |
+03:23:18.6 |
HIP 24729 |
9.84 |
| 2026-05-14 12:00 |
05:17:38.81 |
+03:23:21.6 |
HIP 24729 |
9.70 |
| 2026-05-15 00:00 |
05:17:39.62 |
+03:23:24.6 |
HIP 24729 |
9.56 |
| 2026-05-15 12:00 |
05:17:40.43 |
+03:23:27.6 |
HIP 24729 |
9.43 |
| 2026-05-16 00:00 |
05:17:41.25 |
+03:23:30.5 |
HIP 24729 |
9.29 |
| 2026-05-16 12:00 |
05:17:42.07 |
+03:23:33.4 |
HIP 24729 |
9.16 |
| 2026-05-17 00:00 |
05:17:42.89 |
+03:23:36.3 |
HIP 24729 |
9.03 |
| 2026-05-17 12:00 |
05:17:43.72 |
+03:23:39.1 |
HIP 24729 |
8.90 |
| 2026-05-18 00:00 |
05:17:44.55 |
+03:23:41.9 |
HIP 24729 |
8.78 |
| 2026-05-18 12:00 |
05:17:45.38 |
+03:23:44.7 |
HIP 24729 |
8.66 |
| 2026-05-19 00:00 |
05:17:46.22 |
+03:23:47.4 |
HIP 24729 |
8.54 |
| 2026-05-19 12:00 |
05:17:47.05 |
+03:23:50.1 |
HIP 24729 |
8.42 |
| 2026-05-20 00:00 |
05:17:47.90 |
+03:23:52.8 |
HIP 24729 |
8.31 |
| 2026-05-20 12:00 |
05:17:48.74 |
+03:23:55.4 |
HIP 24729 |
8.19 |
| 2026-05-21 00:00 |
05:17:49.59 |
+03:23:58.0 |
HIP 24729 |
8.09 |
| 2026-05-21 12:00 |
05:17:50.44 |
+03:24:00.5 |
HIP 24729 |
7.98 |
| 2026-05-22 00:00 |
05:17:51.29 |
+03:24:03.1 |
HIP 24729 |
7.88 |
| 2026-05-22 12:00 |
05:17:52.14 |
+03:24:05.6 |
HIP 24729 |
7.79 |
| 2026-05-23 00:00 |
05:17:53.00 |
+03:24:08.0 |
HIP 24729 |
7.69 |
| 2026-05-23 12:00 |
05:17:53.86 |
+03:24:10.4 |
HIP 24729 |
7.60 |
| 2026-05-24 00:00 |
05:17:54.72 |
+03:24:12.8 |
HIP 24729 |
7.52 |
| 2026-05-24 12:00 |
05:17:55.59 |
+03:24:15.2 |
HIP 24729 |
7.44 |
| 2026-05-25 00:00 |
05:17:56.45 |
+03:24:17.5 |
HIP 24729 |
7.37 |
| 2026-05-25 12:00 |
05:17:57.32 |
+03:24:19.8 |
HIP 24729 |
7.30 |
| 2026-05-26 00:00 |
05:17:58.19 |
+03:24:22.0 |
HIP 24729 |
7.23 |
| 2026-05-26 12:00 |
05:17:59.07 |
+03:24:24.2 |
HIP 24729 |
7.18 |
| 2026-05-27 00:00 |
05:17:59.94 |
+03:24:26.4 |
HIP 24729 |
7.12 |
| 2026-05-27 12:00 |
05:18:00.82 |
+03:24:28.5 |
HIP 24729 |
7.08 |
| 2026-05-28 00:00 |
05:18:01.70 |
+03:24:30.6 |
HIP 24729 |
7.04 |
| 2026-05-28 12:00 |
05:18:02.58 |
+03:24:32.7 |
HIP 24729 |
7.00 |
| 2026-05-29 00:00 |
05:18:03.46 |
+03:24:34.7 |
HIP 24729 |
6.97 |
| 2026-05-29 12:00 |
05:18:04.34 |
+03:24:36.7 |
HIP 24729 |
6.95 |
| 2026-05-30 00:00 |
05:18:05.23 |
+03:24:38.7 |
HIP 24729 |
6.93 |
| 2026-05-30 12:00 |
05:18:06.12 |
+03:24:40.6 |
HIP 24729 |
6.92 |
| 2026-05-31 00:00 |
05:18:07.00 |
+03:24:42.5 |
HIP 24729 |
6.92 |
| 2026-05-31 12:00 |
05:18:07.89 |
+03:24:44.3 |
HIP 24729 |
6.93 |
| 2026-06-01 00:00 |
05:18:08.79 |
+03:24:46.1 |
HIP 24729 |
6.94 |
| 2026-06-01 12:00 |
05:18:09.68 |
+03:24:47.9 |
HIP 24729 |
6.95 |
| 2026-06-02 00:00 |
05:18:10.57 |
+03:24:49.6 |
HIP 24729 |
6.98 |