| Parameter |
Value |
| Designation |
C/1972 F1 (Gehrels) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1971-01-06T12:19:44.146560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:19Z |
| Obs used |
18 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1972-08-05.0000000 |
| e |
0.99788599 |
| q (au) |
3.276471 |
| a (au) |
1549.882081 |
| i (deg) |
175.610745 |
| Ω (om, deg) |
24.754752 |
| ω (w, deg) |
128.702717 |
| M (ma, deg) |
0.009312 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.957 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.957 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.900 |
| k |
0.800 |
| 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 |
06:37:13.09 |
+18:57:46.0 |
HIP 31618 |
12.13 |
| 2026-05-12 12:00 |
06:37:14.09 |
+18:57:46.3 |
HIP 31618 |
12.18 |
| 2026-05-13 00:00 |
06:37:15.10 |
+18:57:46.6 |
HIP 31618 |
12.23 |
| 2026-05-13 12:00 |
06:37:16.12 |
+18:57:46.9 |
HIP 31618 |
12.29 |
| 2026-05-14 00:00 |
06:37:17.14 |
+18:57:47.2 |
HIP 31618 |
12.35 |
| 2026-05-14 12:00 |
06:37:18.18 |
+18:57:47.4 |
HIP 31618 |
12.42 |
| 2026-05-15 00:00 |
06:37:19.23 |
+18:57:47.7 |
HIP 31618 |
12.50 |
| 2026-05-15 12:00 |
06:37:20.29 |
+18:57:47.9 |
HIP 31618 |
12.58 |
| 2026-05-16 00:00 |
06:37:21.35 |
+18:57:48.1 |
HIP 31618 |
12.66 |
| 2026-05-16 12:00 |
06:37:22.43 |
+18:57:48.2 |
HIP 31618 |
12.76 |
| 2026-05-17 00:00 |
06:37:23.51 |
+18:57:48.4 |
HIP 31618 |
12.85 |
| 2026-05-17 12:00 |
06:37:24.60 |
+18:57:48.5 |
HIP 31618 |
12.95 |
| 2026-05-18 00:00 |
06:37:25.70 |
+18:57:48.6 |
HIP 31618 |
13.06 |
| 2026-05-18 12:00 |
06:37:26.81 |
+18:57:48.7 |
HIP 31618 |
13.18 |
| 2026-05-19 00:00 |
06:37:27.93 |
+18:57:48.8 |
HIP 31618 |
13.29 |
| 2026-05-19 12:00 |
06:37:29.06 |
+18:57:48.8 |
HIP 31618 |
13.42 |
| 2026-05-20 00:00 |
06:37:30.19 |
+18:57:48.9 |
HIP 31618 |
13.55 |
| 2026-05-20 12:00 |
06:37:31.34 |
+18:57:48.9 |
HIP 31618 |
13.68 |
| 2026-05-21 00:00 |
06:37:32.49 |
+18:57:48.9 |
HIP 31618 |
13.82 |
| 2026-05-21 12:00 |
06:37:33.65 |
+18:57:48.9 |
HIP 31618 |
13.97 |
| 2026-05-22 00:00 |
06:37:34.82 |
+18:57:48.8 |
HIP 31618 |
14.12 |
| 2026-05-22 12:00 |
06:37:36.00 |
+18:57:48.8 |
HIP 31618 |
14.27 |
| 2026-05-23 00:00 |
06:37:37.18 |
+18:57:48.7 |
HIP 31618 |
14.43 |
| 2026-05-23 12:00 |
06:37:38.37 |
+18:57:48.6 |
HIP 31618 |
14.60 |
| 2026-05-24 00:00 |
06:37:39.57 |
+18:57:48.5 |
HIP 31618 |
14.77 |
| 2026-05-24 12:00 |
06:37:40.78 |
+18:57:48.3 |
HIP 31618 |
14.94 |
| 2026-05-25 00:00 |
06:37:41.99 |
+18:57:48.2 |
HIP 31618 |
15.12 |
| 2026-05-25 12:00 |
06:37:43.22 |
+18:57:48.0 |
HIP 31618 |
15.31 |
| 2026-05-26 00:00 |
06:37:44.45 |
+18:57:47.8 |
HIP 31618 |
15.50 |
| 2026-05-26 12:00 |
06:37:45.68 |
+18:57:47.6 |
HIP 31618 |
15.69 |
| 2026-05-27 00:00 |
06:37:46.93 |
+18:57:47.4 |
HIP 31618 |
15.89 |
| 2026-05-27 12:00 |
06:37:48.18 |
+18:57:47.1 |
HIP 31618 |
16.09 |
| 2026-05-28 00:00 |
06:37:49.44 |
+18:57:46.9 |
HIP 31618 |
16.29 |
| 2026-05-28 12:00 |
06:37:50.70 |
+18:57:46.6 |
HIP 31618 |
16.50 |
| 2026-05-29 00:00 |
06:37:51.97 |
+18:57:46.3 |
HIP 31618 |
16.72 |
| 2026-05-29 12:00 |
06:37:53.25 |
+18:57:46.0 |
HIP 31618 |
16.94 |
| 2026-05-30 00:00 |
06:37:54.53 |
+18:57:45.6 |
HIP 31618 |
17.16 |
| 2026-05-30 12:00 |
06:37:55.83 |
+18:57:45.3 |
HIP 31618 |
17.39 |
| 2026-05-31 00:00 |
06:37:57.12 |
+18:57:44.9 |
HIP 31618 |
17.62 |
| 2026-05-31 12:00 |
06:37:58.43 |
+18:57:44.5 |
HIP 31618 |
17.85 |
| 2026-06-01 00:00 |
06:37:59.74 |
+18:57:44.1 |
HIP 31618 |
18.09 |
| 2026-06-01 12:00 |
06:38:01.05 |
+18:57:43.7 |
HIP 31618 |
18.33 |
| 2026-06-02 00:00 |
06:38:02.37 |
+18:57:43.2 |
HIP 31618 |
18.57 |