Solar Bulletin, April 2006
Solar Bulletin |
| THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS - SOLAR COMMITTEE |
Carl E. Feehrer, Editor
9 Gleason Rd.
Bedford, MA 01730 | Email: cfeehrer@hotmail.com
ISSN 0271-8480 |
|
| Volume 62 Number 4 | April 2006 |
|
Table I. Mean Sunspot Numbers for April 2006 [boldface = maximum, minimum] |
Table II. April Observers
|
| Day |
N |
Raw
Mean |
Ra |
| 1 |
28 |
51 |
38 |
| 2 |
32 |
58 |
43 |
| 3 |
24 |
68 |
49 |
| 4 |
28 |
81 |
56 |
| 5 |
20 |
79 |
56 |
| 6 |
27 |
76 |
58 |
| 7 |
32 |
67 |
50 |
| 8 |
35 |
57 |
41 |
| 9 |
31 |
48 |
35 |
| 10 |
25 |
54 |
42 |
| 11 |
29 |
60 |
43 |
| 12 |
29 |
61 |
44 |
| 13 |
32 |
58 |
43 |
| 14 |
34 |
43 |
32 |
| 15 |
34 |
29 |
21 |
| 16 |
25 |
17 |
13 |
| 17 |
33 |
13 |
10 |
| 18 |
33 |
11 |
8 |
| 19 |
32 |
3 |
2 |
| 20 |
29 |
17 |
12 |
| 21 |
20 |
13 |
9 |
| 22 |
28 |
3 |
2 |
| 23 |
26 |
11 |
8 |
| 24 |
31 |
21 |
15 |
| 25 |
26 |
41 |
30 |
| 26 |
35 |
54 |
40 |
| 27 |
31 |
64 |
46 |
| 28 |
31 |
58 |
42 |
| 29 |
23 |
49 |
37 |
| 30 |
31 |
59 |
42 |
| 31 |
--- |
--- |
--- |
|
Means: | 29.1 | 44.1 | 32.2 |
No. of Observers: 55
No. of Observations: 874
|
|
Reporting Addresses |
Sunspot Reports -- email: solar@aavso.org
- postal mail: AAVSO, 25 Birch St. Cambridge, MA 02138
- FAX (AAVSO): (617) 354-0665
| |
SID Solar Flare Reports -- email: noatak@aol.com
- postal mail: Mike Hill
114 Prospect St. Marlboro, MA 01752
|
|
| 19
|
AAP |
P.Abbott |
| 15
|
AJV |
J.Alonso |
| 28
|
ARAG |
G.Araujo |
| 12
|
BARH |
H.Barnes |
| 11
|
BATR |
R.Battaiola |
| 12
|
BEB |
R.Berg |
| 17
|
BERJ |
J.Berdejo |
| 10
|
BLAJ |
J.Blackwell |
| 13
|
BMF |
M.Boschat |
| 1
|
BRAM |
M.Bradbury |
| 19
|
BRAR |
R.Branch |
| 12
|
BROB |
R.Brown |
| 24
|
CHAG |
G.Morales |
| 29
|
CKB |
B.Cudnik |
| 11
|
CLZ |
L.Corp |
| 16
|
COMT |
T.Compton |
| 27
|
CR |
T.Cragg |
| 16
|
DEJV |
J.van Delft |
| 10
|
DEMF |
F.Dempsey |
| 17
|
DGP |
G.Dyck |
| 20
|
FERJ |
J.Fernandez |
| 21
|
FLET |
T.Fleming |
| 20
|
FUJK |
K.Fujimori |
| 6
|
GOEM |
M.Goetz |
| 6
|
HALB |
B.Halls |
| 9
|
HAYK |
K.Hay |
| 17
|
JAMD |
D.James |
| 6
|
JENS |
S.Jenner |
| 23
|
KAPJ |
J.Kaplan |
| 26
|
KNJS |
J.Knight |
| 1
|
KROL |
L.Krozel |
| 11
|
LARJ |
J.Larriba |
| 21
|
MCE |
E.Mochizuki |
| 16
|
MENM |
M.Menegotto |
| 2
|
MEU |
E.Mason |
| 9
|
MMI |
M.Moeller |
| 25
|
OATS |
S.Oatney |
| 21
|
PEKT |
R.Pektas |
| 18
|
RICE |
E.Richardson |
| 24
|
RITA |
A.Ritchie |
| 27
|
SCGL |
G.Schott |
| 12
|
SCHG |
G.Scholl |
| 3
|
SDP |
D.Sharples |
| 13
|
SIMC |
C.Simpson |
| 17
|
STEM |
G.Stemmler |
| 21
|
STQ |
N.Stoikidis |
| 20
|
SUZM |
M.Suzuki |
| 24
|
SZUM |
M.Szulc |
| 26
|
TESD |
D.Teske |
| 14
|
TJV |
J.Temprano |
| 20
|
URBP |
P.Urbanski |
| 19
|
VARG |
A.Vargas |
| 6
|
WILD |
D.Williams |
| 26
|
WILW |
W.Wilson |
| 5
|
WRP |
R.Wheeler |
|
|
 |
Click image to enlarge. Fig. 1. 10 cm Solar Flux and American Relative Sunspot Numbers (Ra) for April 2006
(10cm Source: http://www.drao.nrc.ca/icarus) |
 |
Click image to enlarge. Fig.2 Smoothed Mean Sunspot Numbers (Rsm) from January 2000 to October 2005 (Waldmeier method). |
Presented at the Spring Meeting of the AAVSO, Rockland, IL May 5-7, 2006
Committee Chair and Sunspot Observing Group Leader: Carl E. Feehrer
Solar Flare/SID Observing Group Leader: Mike Hill
Observer Reporting
The progressive diminution in the sun's activity as solar minimum approaches has resulted in a reduced amount of reporting by the corps of sunspot and SID observers. During the period covered by this summary, a total of 333 sunspot reports containing 4611 observations were received, while a total of 102 SID reports were received. The sunspot and SID reports were contributed by 82 and 20 observers, respectively. As always, the contributions were made by an active, widely distributed group of observers from the United States, Canada, Europe, South America, South Africa, India and Australia.
Observer Awards
Three new observers have now met the criteria established for awarding of certificates that recognize significant contributions. SID observer Paul Campbell from Canada and sunspot observers Gerd-Lutz Schott from Germany and James Knight from South Africa have now joined the earlier group of 26 that have achieved this distinction. In accord with tradition, these new observers will be recognized and receive their certificates at the AAVSO's Fall meeting.
Website Activity
Contributions of photos continue to be received and posted to the AAVSO website, though at a much reduced level. Presumably this outcome, like the reduction in reports, is due to the relatively small amount of solar activity.
Reorganization of Solar Committee
Carl Feehrer, chair of the Solar Committee and Sunspot Group Leader since 2000 will step down from his responsibilities in May. Taking his place as chair of the Committee will be Paul Mortfield, a SID observer who lives in Canada. Paul participates in the SOHO program and is active in solar outreach efforts. Daniel Williams, a new volunteer interested in H-alpha and white-light sunspot observing lives in Nebraska and will take over as Sunspot Group Leader. Mike Hill, SID/Solar Flare Group Leader and SID analyst will continue in his present position.
The current chair wishes to thank observers and AAVSO staff all of those for their unstinting support during his tenure and expresses the hope that they will welcome the new team and help to make their service as interesting and enjoyable as they made his.
Acknowledgements
As always, the successful performance of the Solar Committee's work during the reporting period was due to the dedication and activities of our solar observers, AAVSO staff, and headquarters' volunteer Arthur Ritchie. We are grateful to this group for their extensive support.
-------------------------
NOTE: As of May 15, I will no longer be able to guarantee that reports received by postal mail at my local address will be able to be forwarded to AAVSO headquarters in time for processing. Therefore, please be sure to send all regular mail reports and other communiques to the AAVSO headquarters address shown at the bottom of page 1.
Thank you.
-CEF
Michael Hill, SID Analyst
114 Prospect St
Marlborough, MA 01752 USA
noatak@aol.com |
 |
Sudden Ionospheric Disturbances (SID) Recorded During April 2006