Antihelion Source
The Antihelion Source (ANT) is a large, roughly oval area with a size of 30° in right ascension and 15° in declination, centred about 12° east of the solar opposition point on the ecliptic, hence its name. It is not a true shower at all, but is rather a region of sky in which a number of variably, if weakly, active minor showers have their radiants. Until 2006, attempts were made to define specific showers within this complex, but this often proved very difficult for visual observers to achieve. IMO video results from the last decade have shown why, because even instrumentally, it was impossible to usefully define distinct radiants for many of the showers here! Consequently, we currently believe it is best for observers to simply identify meteors from these showers as coming from the ANT alone. At present, we think the July-August α-Capricornids (CAP), and particularly the Southern δ-Aquariids (SDA; because their stream parameters are rather different from the average ANT orbits), should remain discretely observable visually from the ANT, so they have been retained in the Working List, but time and plenty of observations will tell, as ever. Later in the year, the strength of the twin Taurid showers (STA and NTA) means the ANT should be considered inactive while the Taurids are underway, from late September to late November. To assist observers, a set of charts showing the location for the ANT and any other nearby shower radiants is included here, to compliment the numerical positions of Table 6, while comments on the ANT's location and likely activity are given in the quarterly summary notes. |
置顶卡
变色卡
千斤顶
显身卡
