| Parameter |
Value |
| Designation |
270P/Gehrels |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2013-07-18T12:29:23.700480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:10Z |
| Obs used |
381 |
| NEO |
- |
| M1 |
13.700 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-07-20.0000000 |
| e |
0.46760427 |
| q (au) |
3.594521 |
| a (au) |
6.751596 |
| i (deg) |
2.859570 |
| Ω (om, deg) |
225.681440 |
| ω (w, deg) |
211.476072 |
| M (ma, deg) |
257.495456 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.875 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.875 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.503 |
| k |
1.000 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
20:07:18.50 |
-17:31:24.7 |
HIP 99095 |
20.02 |
| 2026-03-26 12:00 |
20:07:28.97 |
-17:30:43.0 |
HIP 99095 |
19.95 |
| 2026-03-27 00:00 |
20:07:39.33 |
-17:30:01.4 |
HIP 99095 |
20.20 |
| 2026-03-27 12:00 |
20:07:49.61 |
-17:29:20.1 |
HIP 99095 |
20.76 |
| 2026-03-28 00:00 |
20:07:59.79 |
-17:28:38.9 |
HIP 99095 |
21.60 |
| 2026-03-28 12:00 |
20:08:09.87 |
-17:27:58.0 |
HIP 99095 |
22.67 |
| 2026-03-29 00:00 |
20:08:19.86 |
-17:27:17.2 |
HIP 99095 |
23.94 |
| 2026-03-29 12:00 |
20:08:29.76 |
-17:26:36.7 |
HIP 99095 |
25.38 |
| 2026-03-30 00:00 |
20:08:39.55 |
-17:25:56.4 |
HIP 99349 |
26.22 |
| 2026-03-30 12:00 |
20:08:49.25 |
-17:25:16.3 |
HIP 99349 |
24.21 |
| 2026-03-31 00:00 |
20:08:58.86 |
-17:24:36.4 |
HIP 99349 |
22.29 |
| 2026-03-31 12:00 |
20:09:08.36 |
-17:23:56.7 |
HIP 99349 |
20.49 |
| 2026-04-01 00:00 |
20:09:17.77 |
-17:23:17.3 |
HIP 99349 |
18.83 |
| 2026-04-01 12:00 |
20:09:27.07 |
-17:22:38.1 |
HIP 99349 |
17.34 |
| 2026-04-02 00:00 |
20:09:36.28 |
-17:21:59.1 |
HIP 99349 |
16.05 |
| 2026-04-02 12:00 |
20:09:45.39 |
-17:21:20.3 |
HIP 99349 |
15.01 |
| 2026-04-03 00:00 |
20:09:54.40 |
-17:20:41.8 |
HIP 99349 |
14.26 |
| 2026-04-03 12:00 |
20:10:03.30 |
-17:20:03.5 |
HIP 99349 |
13.84 |
| 2026-04-04 00:00 |
20:10:12.11 |
-17:19:25.5 |
HIP 99349 |
13.77 |
| 2026-04-04 12:00 |
20:10:20.81 |
-17:18:47.7 |
HIP 99349 |
14.03 |
| 2026-04-05 00:00 |
20:10:29.42 |
-17:18:10.1 |
HIP 99349 |
14.61 |
| 2026-04-05 12:00 |
20:10:37.91 |
-17:17:32.8 |
HIP 99349 |
15.45 |
| 2026-04-06 00:00 |
20:10:46.31 |
-17:16:55.8 |
HIP 99349 |
16.50 |
| 2026-04-06 12:00 |
20:10:54.60 |
-17:16:19.0 |
HIP 99349 |
17.73 |
| 2026-04-07 00:00 |
20:11:02.79 |
-17:15:42.4 |
HIP 99455 |
17.66 |
| 2026-04-07 12:00 |
20:11:10.87 |
-17:15:06.2 |
HIP 99455 |
17.01 |
| 2026-04-08 00:00 |
20:11:18.84 |
-17:14:30.2 |
HIP 99455 |
16.57 |
| 2026-04-08 12:00 |
20:11:26.71 |
-17:13:54.4 |
HIP 99455 |
16.36 |
| 2026-04-09 00:00 |
20:11:34.47 |
-17:13:19.0 |
HIP 99455 |
16.39 |
| 2026-04-09 12:00 |
20:11:42.13 |
-17:12:43.8 |
HIP 99455 |
16.64 |
| 2026-04-10 00:00 |
20:11:49.68 |
-17:12:08.8 |
HIP 99455 |
17.09 |
| 2026-04-10 12:00 |
20:11:57.12 |
-17:11:34.2 |
HIP 99455 |
17.72 |
| 2026-04-11 00:00 |
20:12:04.45 |
-17:10:59.8 |
HIP 99455 |
18.50 |
| 2026-04-11 12:00 |
20:12:11.67 |
-17:10:25.8 |
HIP 99455 |
19.41 |
| 2026-04-12 00:00 |
20:12:18.78 |
-17:09:52.0 |
HIP 99455 |
20.42 |
| 2026-04-12 12:00 |
20:12:25.78 |
-17:09:18.5 |
HIP 99455 |
21.51 |
| 2026-04-13 00:00 |
20:12:32.67 |
-17:08:45.3 |
HIP 99455 |
22.67 |
| 2026-04-13 12:00 |
20:12:39.45 |
-17:08:12.4 |
HIP 99455 |
23.88 |
| 2026-04-14 00:00 |
20:12:46.12 |
-17:07:39.8 |
HIP 99455 |
25.12 |
| 2026-04-14 12:00 |
20:12:52.67 |
-17:07:07.6 |
HIP 99455 |
26.39 |
| 2026-04-15 00:00 |
20:12:59.11 |
-17:06:35.6 |
HIP 99455 |
27.67 |
| 2026-04-15 12:00 |
20:13:05.44 |
-17:06:03.9 |
HIP 99708 |
28.92 |
| 2026-04-16 00:00 |
20:13:11.65 |
-17:05:32.6 |
HIP 99708 |
27.81 |