The Daytime Kappa Leonids meteor shower
Key facts
- Peak
- around 21 September
- Active
- early September to early October
- Rate at peak (ZHR)
- detected by radar; not visible by eye
- Speed
- about 43 km/s
- Radiant
- Leo (about 20° from the Sun in the sky)
- Parent body
- Unknown; a link with comet C/1917 F1 (Mellish) has been suggested
Dates shift slightly from year to year. This year's peak is in the events calendar, and the meteor-shower planner shows how high the radiant climbs from where you live, night by night.
The Daytime Kappa Leonids are a September daytime shower with its radiant in Leo, which in late summer is lost in the Sun's glare. Several radar surveys have recorded it.
The radiant. In late September the Sun is in Virgo, just east of Leo, so the stars of Leo rise shortly before dawn. The shower is named after Kappa Leonis, in the Lion's head, though modern measurements place the radiant somewhat further east. It is above the horizon mainly during daylight.
What we know. The meteoroids enter the atmosphere at about 43 kilometres per second, with a broad maximum around 21 September. The shower has been reported from several radar programmes but has not been studied closely by amateur radio observers.
A possible parent. Researchers comparing meteor orbits with comets have suggested that the Daytime Kappa Leonids may come from comet C/1917 F1 (Mellish), the parent of the December Monocerotids. A single comet can produce more than one shower if its debris has been spread by planetary gravity into several branches, and Earth meets each branch at a different time of year. The link has been proposed but not confirmed.
What to expect. Nothing by eye. By radio or radar, a modest addition to late September activity, overlapping with the Daytime Sextantids, which peak around the end of the month.
How to observe. Radio observers record echoes continuously, and daytime showers appear as rises at times of day when their radiants are high. Comparing September counts with August and October helps to show the extra activity. Separating the Kappa Leonids from the Sextantids requires radar that measures direction.
The idea that one comet may feed several showers through the year is a powerful one: it turns a scattered list of weak streams into a family tree.
Viewing tips
- Use radio or radar detection; this is a daytime shower.
- Record through September and October to see it alongside the Daytime Sextantids.
- Compare morning and afternoon counts to find when the radiant is highest.
- Never look towards the Sun when observing near dawn.
- Watch the Monocerotids in December, which may share the same parent.
Read about the parent: Comet Mellish, and the other comets behind meteor showers.