NOTES ON SUNSPOT GROUPS Group No 0 - = Greenwich group No 23738. (Cf. Photoheliographic Results 1972-1976, Royal Observatory Annals No 13, R.Greenwich Obs.,1980, pp.83,93,102.) This is the only group which survived from 1976 to 1977. Its spot 1 has been rotated onto the disc on 1976 Dec 24 as the original leader of the group. 1 - Belongs to the OLD Cycle (No 20). It is the return of Greenwich group No 23733, born on Dec 7 and passed round the west limb on Dec 17. Our spot 1 is the original Dec 7 leader, i.e.lasting for 30 days. 2 - Cf. group No 6. 4 - On Jan 11-12 both parts of the group form an arc-like configuration. On Jan 13 the leader is strikingly elongated. On Jan 14 a new umbra (U=4) also joins spot 2.1-3 for one day's duration. 6 - Return of group No 2; spot 1 of group 2 returns as spot 1 of group 6; this high latitude spot has a 26-day duration. 10 - On Jan 28 the p-part shows an arc-like configuration. Cf. also group No 18. 11 - After Feb 1 the group develops into a long stream of spots (embedded in an east-west elongated narrow facular region, clearly visible on the 2nd and 3rd); especially the p-part of the group reveals a train-like configuration, it is dissolved by Feb 6. 12 - Initially a single spot at the east limb on Feb 5-6; after a one-day intermittency the p-part shows an arc-like configuration and the whole group develops rapidly to form a long multiple bipolar group. On the southern hemisphere this group is observed to be the farthest from the equator in 1977. 15 - A regular bipolar group of 7-day duration, belonging to the OLD Cycle (No 20). 18 - In the beginning a single spot. Spot 1.12 of group 10 returns as spot 1 of group 18 and passes round the west limb, i.e. lasting longer than 31 days. On Feb 18 five short-lived little following spots appeared; a few seen even on the following days, too. 27 - On Apr 2 a one-day group of an unknown polarity single spot (U+P=5, B=27.9, L=247.6) is observed NE of spot 2. 29 - This spot region is rather a complex of two groups of spots. Spots 1 and 3 rotate onto the disc and are probably the remnants of two old groups. On Apr 13 an emergence of new spots occurs in the middle of the region. All these new spots spread out and fade away by Apr 23. The remaining spot 1 passes round (cf. group 35), while spot 3 also dies out before reaching the west limb. 31 - On Apr 23 both parts of the group may be regarded as arc-like configurations. Cf. also group No 35. 32 - The group rotates onto the disc as a single spot and disintegrates slowly in 8 days. A one-day group of an unknown polarity single spot (U+P=2, B=-26.7, L=200.0) is observed SW of the group on the last day of its life on May 4. 33 - In a single extended facular region a clear double group. After rapidly approaching one another spots 3.12 and 2.1 are blown up into several pieces by May 5. On May 4, at the maximal development of the group, a one-day group of a single unknown polarity spot (U+P=1, B=28.9, L=128.8) appears S of spot 3.12. 35 - On May 9, spot 1 of group 35 is the return of spot 1.12, the only survivor at the west limb of group 29, and spot 3 rotates onto the disc on the next day, the return of spot 1.2 of group 31. Both of these two old leader spots stand alone for a couple of days. Spot 3 gradually decays and disappeares by May 16, when spot 1 starts to decline rapidly and dies out in two days. Spot 1 lives more than 38 days, while spot 3 lasts 25 days. On may 15, the little spot 2 emerges and remains the last to disappear (May 19). However, in the meantime, on May 16 in the vicinity where spot 3 disappeared, a bipolar cluster of several little spots emerges suddenly, where the opposite polarities lie roughly in a north-south direction. West of spot 1 a similarly directed spot pair is also visible. 42 - On May 30 spots 2.0, 2.1, 2.2, 2.3, 2.4 and 2.5 form a train-like spot configuration along an arc, which remains perceivable for three more days. Cf. also group No 51. 43 - On June 2, the f-part shows an arc-like configuration. Cf. group No 52. 44 - On June 3, in the slowly decaying simple bipolar group after the disappearance of the f-part, a new bipolar pair of spots emerges which should also be regarded as a close but different group. 45 - On June 7 the spot 2.1-3 has a C-shape and it reveals a fairly similar form on the next day. 47 - On June 15 W of spot 1 an ephemeral bipolar pair of two little spots are observed exactly north-south of one another. Cf. also group No 60. 51 - The group is nearly always a slowly shrinking single spot. This spot 1 is the return of spot 1.1-4 of group 42. On June 27, on the last day of the spot which lasts for 31 days, north of it, a one-day group of two unknown polarity spots emerges (U+P=2, B=26.8, L=211.3 and U+P=2, B=23.9, L=208.2). 52 - Spot 1.1 of the group, which is for two days near the east limb a separated spot, is the return of spot 3 of group 43. Spot 1.1 (a part of spot 1.1-3) passes over the west limb, i.e. it lives more than 31 days. 53 - The largest group of the New Cycle (No 21) in 1977. On June 26 almost all of their umbrae are embedded in a single penumbra. Its leading umbra (1.1) enters the disc as U > 60 and passes the west limb as (1.12) U > 30. Cf. also group No 61. 54 - The smallest group of the OLD Cycle (No 20) in 1977. 60 - Spot 1 is the return of spot 1 of group 47. It is the only spot of group 60. Over five days spot 1 remains quite stable but starts to disintegrate slowly by July 10 and disappears on July 14. This spot lives for more than 37 days. On July 9 a spot of north polarity appears south-west of spot 1, which after an intermittence of two days probably reappears as one of the members of a reversed polarity little spot pair. 61 - The group consists only of spot 1, the return of spot 1.12 of group 53. The spot is in slow decay, however a weak activity is noticeable around it for four days beginning with the fifth day of its passage over the disc. A few little spots represent an ephemeral f-part for three days. Moreover, two one-day groups also emerge not far from spot 1. On June 24, a p-polarity spot of U+P=2, B=12.6, L=141.0 and on July 26, an unknown polarity spot of U+P=1, B=11.7, L=149.3. 62 - Cf. group No 75. 70 - A single old leader rotates onto the disc and remains a quite stable spot which hardly grows less as it disappears at the west limb. It returns as the leader of group 84 again alone after a forthnight and as a diminished spot once more survives alone when it passes round the west limb (it lives more than 41 days). During both its disc passages new spot activities develop close eastwards of this old leader. The extended NE part of group 70 in itself (i.e. without the old leader) becomes a compact multiple spot group for a couple of days, while the group 84 may be regarded only as a rather simple double group. 72 - The group mainly consists of three successive bipolar spot pairs. The latest passes round the west limb and its leader, spot 5, lasting for 21 days, returns as spot 1 of group 87. 75 - Spot 1 lasting for 23 days is the return of spot 5 of group 62. The life history of group 62 has some resemblance to group 72. 78 - The only group of higher heliographic latitude than 10 deg, whose polarity distribution corresponds to that of the OLD Cycle (No 20). 79 - On Aug 25 the f-part of the group shows an arc-like configuration. The spots of the group reveal an almost straight line on the disc during the last six days of its disc passage. 84 - Cf. group 70. 87 - Cf. group 72. 90 - The very largest group of the year 1977 belongs to the OLD Cycle (No 20). The group, born on the far side of the Sun, rotates onto the disc as a great compact group of several quasi-parallel close bipolar spot pairs. The most persistent pair of umbrae 1.1 and 2.1 (which returns in the next rotation), together with the pair of 3 and 4.12, reveals the principal characteristics of the group, most clearly on Sep 17. The main leader comprises two umbrae of unequal areas; their joining line displays rotation. 92 - On Sep 26, south of the f-part of the group, a one-day group of an unknown polarity spot (U+P=2, B=-28.5, L=95.1). 101 - On the northern hemisphere this small group is observed farthest from the equator in 1977. 104 - Return of the OLD Cycle group 90. Spots 1 and 2 of group 104 are the survivors of spots 1.1 and 2.1 of group 90. Spot 1 slowly disintegrates and disappears near the central meridian, i.e. the spot lasts for more than 33 days. Closely following the spot pair 1-2, the bipolar "subgroup" 3-4 also rotates onto the disc. One of their new spots (3.0) emerges just within the penumbra of spot 2, and they build a classic delta-spot for a week. Finally, after separation, only spot 2 survives and passes round the west limb as the only spot of the whole group, i.e. it twice crosses the solar disc and lasts for more than 40 days. On Oct 16, NE of the group, there is also an unknown polarity single spot of a one-day group. (U+P=2, B=10.1, L=197.7) In the next rotation, on Nov 7, a one-day group is observed (near the central meridian) approximately at the same heliographic coordinates as the group 104. The ephemeral little group of unknown polarity may be regarded as the revival of group 104. It consists of a single spot (U+P=1, B=6.3, L=215.1) and a small cluster of three near-by spots (U+P=4, B=4.3, L=205.5). 112 - By Oct 19 the group abruptly develops in a one-day period and develops further while rapidly moving. On Oct 21, W of the leader of the group, an unknown polarity single spot of a one-day group is seen (U+P=1, B=-26.0, L=98.0). 115 - A multiple group where altogether six small unrelated bipolar spot pairs can be observed; the places of their emergence (with one exception) are successively shifted toward west. On Oct 29, at maximal development, all of its spots are almost in a straight line. 119 - From Oct 30 to Nov 3, west of spot 1, at least one little spot of opposite polarity is observed. These ephemeral spots of N polarity, together with the S polarity spot 1.01, may be regarded as a small group of inverted polarity. 123 - Between Nov 9 and 11 spot 2.0 moves parallelly with spot 1, i.e. quite unusually. 124 - On Nov 17, SE of the group, an unknown polarity single spot of a one-day group is seen (U+P=1, B=34.5, L=75.5). 125 - Cf. group 136. 129 - The group has an abrupt rise and development by Nov 17. (During the same one-day period the group 124 also develops into a delta-group in spite of the fact that they are more than 10 deg apart in both coordinates.) 135 - An old leader enters the disc with a few close companions of the same polarity. At central meridian passage, close north of it, a new bipolar group of several small spots emerges which disappears in a few days. The original large leader (1) alone passes round the west limb and on Dec 27 returns as spot 1 of group 153 (it crosses the solar disc a second time, slowly disintegrating, i.e. lasting for more than 39 days). 136 - Spot 1 of the group, passing over the disc as a fairly stable leader, is the return of spot 1.12 of group 125, born near the west limb and lasting more than 29 days. 140 - Enters the disc in the same photospheric facular region in which group 123 and 128 emerged and passes round the west limb. The group elongated to 17 longitudinal degrees reveals an almost straight line on the disc, especially on Dec 12-13. On Dec 10 an unknown polarity spot of a one-day group is also seen (U+P=5, B=-23.3, L=123.7). 143 - The lowest latitude group in 1977. Accordingly to a polarity determination it belongs to the NEW Cycle (No 21). 147 - SE of the group on Dec 16, a one-day group of two N-polarity spots are observed (U=2, U+P=10, B=-27.2, L=53.5 and U=2, U+P=9, B=-26.3, L=51.9). 151-154 are not yet included in the General Catalogue of Sunspot Groups as they survive to 1978 and therefore no more notes are given here (cf. also group 135).