Does Detect Magic require an item to be visible, to say it's magic?

[A.T.Field]

Hi all, in short, the question is that one in the title.

To add context, we are running the Horrors demo. Try to not give me spoilers, but I don't know if the GM changed anything, so here's what I know: we just talked with the lady wizard (or whatever she is) and she explained we must quench a candle that has been put in the graveyard, since it raises undead from nearby corpses.
Thing is this candle is only visible at night, so normally the PCs would be forced to look for it during the more dangerous hours of darkness. But since it's a magic item, I (playing a 1st level Druid) asked if I could find it during the day by scanning the area with at-will Detect Magic.
The GM wasn't sure because maybe you have to actually see an item to have its magic aura outlined, but Detect Magic doesn't say anything about visible or invisible things.
So (for the next times the issue may come up too), how would it work exactly, and is there any relevant part in the rulebook about this?

[The Archive]

If it's just sitting around in the graveyard somewhere, there's no reason that you wouldn't be able to use detect magic to search for it. Your search would be limited by detect magic's 60ft cone, however.

Detect magic doesn't require you to directly see a magical object to be able to tell that something magical is there.

PRD wrote:

Each round, you can turn to detect magic in a new area. The spell can penetrate barriers, but 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt blocks it.

However, you could not tell what the magical aura belonged to if you couldn't directly see the object. You would only have the information garnered from detect magic: you would know that there is a magical aura, where that aura is, and how strong it is assuming you concentrated for the full three rounds. As well, you could discern what kind of aura or magic item is present as said in the spell.

[Astral Wanderer]

Since the spell doesn't specify you need to see a target... you don't need it.

Also, if you required sight, how would you detect the magic aura of an enemy under the effects of Invisibility (against which Detect Magic or other Detect effects such as the Paladin's Detect Evil are used regularly, in games)?
Or even the aura of a spell affecting an area but not specifically an item or creature, such as Desecrate; would you need to "see the air"?

Detect Magic (and Chaos/Evil/Good/Law and the like) acts as a sixth sense, it doesn't rely on the others. You just feel it.

In context, I didn't read the demo, but unless there are other effects at work (whether by adventure design or GM's own decision) and the item is just invisible (and not beyond a barrier like the specified ones), Detect Magic should reveal its aura. Of course, it'll take some time, given the spell's limited radius, but perfectly feasible.

Beware that Detect Magic won't reveal Undead creatures; they aren't considered magical. But if any of them is under the effects of some spell or is carrying a magic item, you will perceive the spell's or item's aura. And if you're at the third round of concentration, perceiving locations, you'll feel if they move and where (as long as they remain within the spell's cone; if they move out, even if you redirect the cone, you have to go through the three rounds again, to locate).