Burst of sunlight

Close range with himself? This makes absolutely no sense.

2. Determine Range

Each round of combat is fought at either close range or long range. Close range is the default for each round.

The range is either close to both, or long to both.

◼ Resolve Strike: The effects of the strikes from both minions are resolved simultaneously. Most strikes are effective only at close range, unless the strike is identified as ranged, does “R” damage

I stand by my point. Burst of sunlight is a strike that does two types of damage. One type is R damage (from strike) and the other one is an environmental "regular" damage that, is subject to the range of the Combat. There is no "close range with himself" anywhere.

I have been away for a few years, but who can examine this question "offi ialy", like LSJ did in the past? Who has the official saying in this kind of questions?

Carrion Crows for example uses the R damage definition and it has nothing to do with the choose strike step.

OK just forget my answer, Ankha answered it better. By "close range with himself" I meant "at long range" means there's a distance between your minion and opposing minion. On the other hand, the effects played by your minion happen "near him", so no need for "R" requirement.
This was just to help you imagine / understand it better, it has nothing to do with the rules and rulebook.