Tha ainm Gàidhlig air fear de na reul-bhadan a’ cur nar cuimhne tachartas iongantach anns na speuran gach bliadhna / The Gaelic name for the constellation Ursa Minor reminds us to keep our eyes open this month for an unusual cosmic event.
Reul-bhad nan Dreagan
Tha an t-ainm Gàidhlig air fear de na reul-bhadan as follaisiche a’ cuimhneachadh tachartas iongantach bliadhnail a ghabhas faicinn anns an Dùbhlachd. ’S e an reul-bhad An Dreagbhod no Ursa Minor ‘mathan beag’, no an Little Dipper mar a chanar ris ann an Ameireagaidh. Tha e mu choinneimh reul-bhad eile car coltach, a tha eadhon nas ainmeile – An Crann-arain. Fhuair An Dreagbhod ainm air sgàth ’s gum bithear a’ faicinn frasan dhreagan anns a’ cheàrnaidh sin dhen iarmailt a h-uile bliadhna anns an t-seachdain ron Nollaig.
Bha aithneachadh an Dreagbhoid riamh cudromach do mhac-an-duine, gu h-àraidh do mharaichean na seann aimsire. Air a cheann a-mach dheth tha an reul bhrèagha, An Reul-iùil, a tha air leth feumail oir bidh i a’ comharrachadh na h-àird’ a tuath fad na h-oidhche is fad na bliadhna.
Tha dùil am-bliadhna gum faicear na dreagan seo (‘dreagan mathain’ no ursids) eadar 17 agus 24 Dùbhlachd, agus iad aig an ìre as fheàrr aig grian-stad a’ gheamhraidh nuair a chithear suas ri deich dreagan gach uair a thìde. Airson am faicinn, coimheadaibh air ceann a tuath na h-iarmailt. Ge-tà, bidh a’ ghealach làn am-bliadhna aig an aon àm, agus cha bhi iad cho faicsinneach ’s as àbhaist.
The Meteor Constellation
An unusual annual cosmic phenomenon is remembered in the Gaelic name for one of the best-known of constellations, which is readily visible at this time of year. The star-cluster in question is Ursa Minor ‘little bear’, also known as the Little Dipper, which appears almost as an adjacent mirror image of an even more famous grouping – The Plough. The Gaelic name for Ursa Minor is An Dreagbhod, derived from dreag ‘meteor’ and bad ‘constellation’. The name recognizes the annual occurence of a meteor shower, known as the Ursids, in that part of the heavens during the week leading up to Christmas.
An Dreagbhod was for long an important constellation to recognise, particularly for mariners. At its outer end is Polaris, the Pole Star, known in Gaelic as An Reul-iùil ‘the guiding star’ because of its usefulness to navigators. It hardly moves through the night or year, and always indicates north.
This year, it is expected that the Ursids will be active on 17-24 December and that they will peak on the night of 22-23 December, when as many as ten meteors per hour might be observed. To find them, locate the Pole Star which sits above the North Pole. However, the peak activity also coincides this year with a full moon, which will reduce their visibility.