| Parameter |
Value |
| Designation |
274P/Tombaugh-Tenagra |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2013-02-23T13:58:11.107200Z |
| Orbit solution date (soln_date, UTC) |
2024-04-13T16:43:06Z |
| Obs used |
915 |
| NEO |
- |
| M1 |
10.900 |
| K1 |
14.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-12-01.0000000 |
| e |
0.43970884 |
| q (au) |
2.445176 |
| a (au) |
4.364118 |
| i (deg) |
15.832722 |
| Ω (om, deg) |
81.368553 |
| ω (w, deg) |
38.590174 |
| M (ma, deg) |
109.234659 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.175 + 5.885\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.175 |
| n |
5.885 |
| gf |
1.000 |
| gb |
-0.893 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
20:13:11.76 |
-28:35:14.0 |
HIP 99489 |
23.92 |
| 2026-05-12 12:00 |
20:13:11.12 |
-28:36:18.7 |
HIP 99489 |
23.52 |
| 2026-05-13 00:00 |
20:13:10.30 |
-28:37:24.0 |
HIP 99489 |
23.11 |
| 2026-05-13 12:00 |
20:13:09.29 |
-28:38:29.8 |
HIP 99489 |
22.72 |
| 2026-05-14 00:00 |
20:13:08.11 |
-28:39:36.1 |
HIP 99489 |
22.33 |
| 2026-05-14 12:00 |
20:13:06.74 |
-28:40:43.0 |
HIP 99489 |
21.95 |
| 2026-05-15 00:00 |
20:13:05.19 |
-28:41:50.5 |
HIP 99489 |
21.59 |
| 2026-05-15 12:00 |
20:13:03.46 |
-28:42:58.4 |
HIP 99489 |
21.24 |
| 2026-05-16 00:00 |
20:13:01.54 |
-28:44:06.9 |
HIP 99489 |
20.92 |
| 2026-05-16 12:00 |
20:12:59.45 |
-28:45:15.9 |
HIP 99489 |
20.63 |
| 2026-05-17 00:00 |
20:12:57.17 |
-28:46:25.4 |
HIP 99489 |
20.38 |
| 2026-05-17 12:00 |
20:12:54.71 |
-28:47:35.4 |
HIP 99489 |
20.16 |
| 2026-05-18 00:00 |
20:12:52.07 |
-28:48:46.0 |
HIP 99489 |
19.99 |
| 2026-05-18 12:00 |
20:12:49.24 |
-28:49:57.0 |
HIP 99489 |
19.88 |
| 2026-05-19 00:00 |
20:12:46.24 |
-28:51:08.5 |
HIP 99489 |
19.82 |
| 2026-05-19 12:00 |
20:12:43.05 |
-28:52:20.5 |
HIP 99489 |
19.82 |
| 2026-05-20 00:00 |
20:12:39.68 |
-28:53:33.0 |
HIP 99489 |
19.90 |
| 2026-05-20 12:00 |
20:12:36.13 |
-28:54:45.9 |
HIP 99489 |
20.05 |
| 2026-05-21 00:00 |
20:12:32.40 |
-28:55:59.3 |
HIP 99489 |
20.28 |
| 2026-05-21 12:00 |
20:12:28.49 |
-28:57:13.2 |
HIP 99489 |
20.59 |
| 2026-05-22 00:00 |
20:12:24.39 |
-28:58:27.5 |
HIP 99489 |
20.99 |
| 2026-05-22 12:00 |
20:12:20.12 |
-28:59:42.3 |
HIP 99489 |
21.48 |
| 2026-05-23 00:00 |
20:12:15.67 |
-29:00:57.5 |
HIP 99489 |
22.05 |
| 2026-05-23 12:00 |
20:12:11.04 |
-29:02:13.2 |
HIP 99489 |
22.71 |
| 2026-05-24 00:00 |
20:12:06.23 |
-29:03:29.2 |
HIP 99489 |
23.45 |
| 2026-05-24 12:00 |
20:12:01.24 |
-29:04:45.7 |
HIP 99489 |
24.28 |
| 2026-05-25 00:00 |
20:11:56.07 |
-29:06:02.6 |
HIP 99489 |
25.19 |
| 2026-05-25 12:00 |
20:11:50.73 |
-29:07:19.9 |
HIP 99489 |
26.18 |
| 2026-05-26 00:00 |
20:11:45.20 |
-29:08:37.6 |
HIP 99553 |
25.25 |
| 2026-05-26 12:00 |
20:11:39.50 |
-29:09:55.7 |
HIP 99553 |
24.32 |
| 2026-05-27 00:00 |
20:11:33.63 |
-29:11:14.2 |
HIP 99553 |
23.50 |
| 2026-05-27 12:00 |
20:11:27.57 |
-29:12:33.0 |
HIP 99553 |
22.81 |
| 2026-05-28 00:00 |
20:11:21.34 |
-29:13:52.3 |
HIP 99553 |
22.27 |
| 2026-05-28 12:00 |
20:11:14.94 |
-29:15:11.8 |
HIP 99553 |
21.89 |
| 2026-05-29 00:00 |
20:11:08.36 |
-29:16:31.8 |
HIP 99553 |
21.70 |
| 2026-05-29 12:00 |
20:11:01.60 |
-29:17:52.0 |
HIP 99553 |
21.71 |
| 2026-05-30 00:00 |
20:10:54.67 |
-29:19:12.6 |
HIP 99553 |
21.92 |
| 2026-05-30 12:00 |
20:10:47.57 |
-29:20:33.6 |
HIP 99350 |
21.01 |
| 2026-05-31 00:00 |
20:10:40.30 |
-29:21:54.8 |
HIP 99350 |
19.01 |
| 2026-05-31 12:00 |
20:10:32.85 |
-29:23:16.4 |
HIP 99350 |
17.01 |
| 2026-06-01 00:00 |
20:10:25.23 |
-29:24:38.3 |
HIP 99350 |
15.02 |
| 2026-06-01 12:00 |
20:10:17.43 |
-29:26:00.4 |
HIP 99350 |
13.05 |
| 2026-06-02 00:00 |
20:10:09.47 |
-29:27:22.9 |
HIP 99350 |
11.15 |