메타데이터

항목	값
Designation	8P/Tuttle
Type	P
Perihelion (tp_cal, UTC)	2008-01-27T00:25:56.539200Z
Orbit solution date (soln_date, UTC)	2022-05-02T08:47:13Z
Obs used	1768
NEO	Yes
M1	14.600
K1	4.500
PC	-

Osculating 궤도요소

항목	값
Epoch (epoch_cal, TDB)	2008-08-23.0000000
e	0.81978762
q (au)	1.027263
a (au)	5.700291
i (deg)	54.981969
Ω (om, deg)	270.342162
ω (w, deg)	207.511518
M (ma, deg)	15.134474

밝기

산란 + 전체 선형

$$ M_a = (9.885 + 4.854\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

모델 상수

항목	값
H0	9.885
n	4.854
gf	1.000
gb	-0.500
k	1.000
δ90	10.000

파라미터	기호	범위	설명
태양·지구거리 1 AU에서의 절대등급	H0	-5 to 20	혜성의 고유 밝기
광도 기울기 파라미터	n	2 to 6	태양거리 변화에 따른 밝기 변화율
전방 산란 비대칭 계수	gf	0.8 to 1	전방 산란의 강도
후방 산란 비대칭 계수	gb	-1 to -0.5	후방 산란의 강도
분할 계수	k	0.8 to 1	전·후방 산란 기여도 비율
먼지/가스 밝기 비	δ90	1 to 10	코마에서 먼지 산란 대비 가스 방출의 상대 기여

참고: EPSC-DPS2025-160

잔차 (구간 선형)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

시작일 (UTC)	끝 (UTC)	a	b
2020-06-21	2021-10-15	-12.4684	-1.024
2021-10-15	2021-08-27	+7.6790	-2.670
2021-08-27	2022-03-19	-2.4327	+1.020

log10 r = log10(태양거리/AU), Δ = 지구거리(AU)

천체력

Date/Time (UTC)	RA (J2000)	Dec (J2000)	Nearest HIP	Dist from HIP (arcmin)
2026-07-29 00:00	18:31:49.35	-06:37:55.6	HIP 90976	29.23
2026-07-29 12:00	18:31:38.96	-06:38:08.7	HIP 90976	31.31
2026-07-30 00:00	18:31:28.64	-06:38:22.2	HIP 90847	32.34
2026-07-30 12:00	18:31:18.38	-06:38:36.0	HIP 90847	33.23
2026-07-31 00:00	18:31:08.18	-06:38:50.1	HIP 90847	34.29
2026-07-31 12:00	18:30:58.05	-06:39:04.6	HIP 90847	35.50
2026-08-01 00:00	18:30:47.99	-06:39:19.4	HIP 90847	36.84
2026-08-01 12:00	18:30:38.00	-06:39:34.5	HIP 90847	38.29
2026-08-02 00:00	18:30:28.08	-06:39:49.9	HIP 90617	38.47
2026-08-02 12:00	18:30:18.22	-06:40:05.7	HIP 90652	37.76
2026-08-03 00:00	18:30:08.44	-06:40:21.8	HIP 90652	37.14
2026-08-03 12:00	18:29:58.72	-06:40:38.2	HIP 90652	36.66
2026-08-04 00:00	18:29:49.08	-06:40:54.9	HIP 90652	36.33
2026-08-04 12:00	18:29:39.51	-06:41:11.9	HIP 90652	36.16
2026-08-05 00:00	18:29:30.02	-06:41:29.3	HIP 90652	36.13
2026-08-05 12:00	18:29:20.60	-06:41:46.9	HIP 90652	36.25
2026-08-06 00:00	18:29:11.25	-06:42:04.8	HIP 90652	36.51
2026-08-06 12:00	18:29:01.98	-06:42:23.1	HIP 90512	36.02
2026-08-07 00:00	18:28:52.79	-06:42:41.6	HIP 90512	35.51
2026-08-07 12:00	18:28:43.67	-06:43:00.4	HIP 90512	35.15
2026-08-08 00:00	18:28:34.64	-06:43:19.6	HIP 90512	34.94
2026-08-08 12:00	18:28:25.68	-06:43:39.0	HIP 90512	34.89
2026-08-09 00:00	18:28:16.80	-06:43:58.6	HIP 90512	34.99
2026-08-09 12:00	18:28:08.01	-06:44:18.6	HIP 90379	33.72
2026-08-10 00:00	18:27:59.29	-06:44:38.8	HIP 90379	31.95
2026-08-10 12:00	18:27:50.66	-06:44:59.3	HIP 90379	30.24
2026-08-11 00:00	18:27:42.11	-06:45:20.1	HIP 90379	28.61
2026-08-11 12:00	18:27:33.65	-06:45:41.1	HIP 90379	27.06
2026-08-12 00:00	18:27:25.27	-06:46:02.4	HIP 90379	25.59
2026-08-12 12:00	18:27:16.98	-06:46:24.0	HIP 90379	24.23
2026-08-13 00:00	18:27:08.77	-06:46:45.7	HIP 90379	22.99
2026-08-13 12:00	18:27:00.65	-06:47:07.8	HIP 90379	21.87
2026-08-14 00:00	18:26:52.62	-06:47:30.1	HIP 90379	20.89
2026-08-14 12:00	18:26:44.68	-06:47:52.6	HIP 90379	20.08
2026-08-15 00:00	18:26:36.82	-06:48:15.3	HIP 90379	19.44
2026-08-15 12:00	18:26:29.06	-06:48:38.3	HIP 90379	18.97
2026-08-16 00:00	18:26:21.38	-06:49:01.5	HIP 90379	18.70
2026-08-16 12:00	18:26:13.80	-06:49:25.0	HIP 90379	18.62
2026-08-17 00:00	18:26:06.30	-06:49:48.6	HIP 90379	18.73
2026-08-17 12:00	18:25:58.90	-06:50:12.5	HIP 90379	19.02
2026-08-18 00:00	18:25:51.59	-06:50:36.6	HIP 90379	19.46
2026-08-18 12:00	18:25:44.38	-06:51:00.8	HIP 90379	20.06
2026-08-19 00:00	18:25:37.26	-06:51:25.3	HIP 90238	18.98