AAVSO: Solar Bulletin February, 2001

Solar Bulletin
THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS - SOLAR DIVISION
Carl E. Feehrer, Editor 9 Gleason Rd. Bedford, MA 01730	Email: cfeehrer@hotmail.com ISSN 0271-8480

Volume 57 Number 2	February 2001

Table I. Mean Sunspot Numbers for February

Table II. February Observers

Day	N	Raw	s.d.	K-corrected	s.d.	s.e.
1	24	98	4.3	76	2.9	0.59
2	28	112	5.5	88	3.6	0.68
3	38	128	7.0	102	4.5	0.73
4	23	134	6.7	107	4.5	0.94
5	26	139	8.2	112	5.5	1.08
6	32	148	8.7	122	6.1	1.08
7	30	147	8.5	125	5.6	1.02
8	32	151	7.7	124	5.1	0.90
9	32	154	9.7	128	6.3	1.11
10	39	129	6.5	103	4.6	0.74
11	35	120	5.4	100	4.6	0.78
12	33	90	5.3	75	4.3	0.75
13	27	104	4.0	84	2.9	0.56
14	21	95	3.5	81	2.0	0.44
15	29	97	3.0	79	2.5	0.46
16	29	78	4.9	68	3.3	0.61
17	35	80	4.1	66	3.0	0.51
18	38	96	4.9	81	3.4	0.55
19	34	103	5.3	84	3.2	0.55
20	35	109	5.0	88	3.7	0.63
21	37	129	5.5	102	3.9	0.64
22	35	107	6.0	84	3.8	0.64
23	36	86	5.7	72	3.8	0.63
24	27	79	5.1	66	3.7	0.71
25	35	78	3.9	62	2.5	0.42
26	39	73	4.4	61	3.0	0.48
27	31	62	3.6	53	2.6	0.47
28	36	68	4.1	57	3.1	0.52
29	---	---	---	---	---	---
30	---	---	---	---	---	---
31	---	---	---	---	---	---
Means:	32	106.9		87.5
No. of Observations: 896 No. of Observers: 65

Reporting Addresses

Sunspot Reports -- email: solar@aavso.org: postal mail: AAVSO, 25 Birch St. Cambridge, MA 02138; FAX (AAVSO): (617) 354-0665
SES Reports -- email: noatak@aol.com: postal mail: Mike Hill 114 Prospect St. Marlboro, MA 01752
Magnetometer Reports -- email: capaavso@aol.com: postal mail: Casper Hossfield PO Box 23, New Milford, NY 10959; FAX: (973) 853-2588 or (407) 482-3963

Table III. Means of Raw Group Counts for February 2001
Day	Mn. Grps.	Day	Mn. Grps.	Day	Mn. Grps.	Day	Mn. Grps.
1	6.7	9	10.0	17	6.1	25	4.6
2	6.8	10	8.4	18	7.0	26	4.0
3	7.9	11	8.5	19	7.0	27	3.7
4	8.9	12	6.8	20	6.7	28	4.2
5	8.6	13	7.7	21	8.2	29	---
6	8.3	14	7.3	22	6.8	30	---
7	8.3	15	7.6	23	5.4	31	---
8	9.6	16	6.1	24	5.0	Mn.	7.01

Fig.1 Comparison of Ri (provisional) and Ra estimates for February.
(Ri Source: http://sidc..oma.be/index.php3)

Smoothed Mean Sunspot Number (Rsm) for August 2000: 123.0

Fig.2 Monthly Ra and Smoothed Mean Sunspot Numbers (Waldmeier method).