[Overbyte]

So the recent talk about auras, and living, etc made me think about some questions I've been wanting to ask the community.

SR5 p.142
Assensing is a magic user’s ability to read and interpret fluctuations in the astral world. This skill allows practitioners to learn information by reading astral auras. Only characters capable of astral perception may take this skill. For more information, see Astral Perception.

SR5 p.312-313
Without attempting to read an aura, you can still get an impression of what type of aura it is (spell, ritual, spirit, living creature, foreboding horror from beyond all mortal ken, etc.).
Like physical perception, you don’t need to make a test to see things that are immediately obvious (and since astral forms are bright and vibrant, this means that most astral forms are easy to spot). You only need to roll the dice when your target is trying to hide or when you’re trying to observe in detail—then you make an Assensing Test to see what you can see.

So you are Astral Perceiving.. looking around.. and you make your perception roll.. so you spot that aura trying to hide in the corner. The other auras are obvious so you don't need a perception roll to see them. But one interests you so you assense it to get more information.

Questions:
1) Is it obvious or perceivable that your Astrally Perceiving? (By someone mundane or not perceiving/astral)
2) It seems that "Astral Perception" and Assensing" are the same roll so you use your Assensing roll for the hiding aura.
3) How much can do you allow to be seen just by perceiving an aura?
4) Is it obvious you are assensing something? (Are you "staring" at it)? And is it obvious/not on both planes?
5) When you assense does it take time?  How much? (This relates to #2)

I have my may of handling all this, but I'm wondering what other think, or if there is some supporting material for doing it a different way.
It can make quite a difference, particularly if you are dual-natured.

[Stainless Steel Devil Rat]

To me, Perception was always the skill to notice things, especially hiding things, even on the astral.

Assensing, again imo, should only come into play once you've spotted the aura and then you want to figure out what you just spotted is.

As for hiding that you're assensing... I believe there's no way to hide that you're using astral perception.  Even masking your aura to make you look like a mundane just means you look like a mundane using astral perception.  So... limited value there

Of course you can be astrally percieving without reading an aura, so it's not necessarily a given that someone who can see you astrally knows you're reading their aura.  But again, your curiosity/interest is hard to hide as it's a surface emotion.

[Michael Chandra]

I can't remember if it's possible to notice someone's astrally perceiving, asides from tossing them a mana spell on the astral and seeing if it hurts them.

[Kiirnodel]

1) Is it obvious or perceivable that your Astrally Perceiving? (By someone mundane or not perceiving/astral)
I've always ruled that it is obvious that something is happening. The person who is Astrally Perceiving gets this far-off stare and is obviously not paying attention to the world around them. So while an observer might not be able to tell specifically that you are Astrally Perceiving, they know something is going on. It could just as easily be that you are paying attention to an AR window, or using the Matrix in another way.

2) It seems that "Astral Perception" and Assensing" are the same roll so you use your Assensing roll for the hiding aura.
Yes, according to the rules as written you roll the Assensing skill to spot things that are hidden while using Astral Perception.

3) How much can do you allow to be seen just by perceiving an aura?
I'm not sure what you are asking here. If you are asking how much can a person know about something just through the aura? That's what the Assensing table is for.

4) Is it obvious you are assensing something? (Are you "staring" at it)? And is it obvious/not on both planes?
In the same way that you know when someone is looking at you. If you want to try and hide that you are assensing someone, it would probably take a Con or Stealth check to hide your critical view.

5) When you assense does it take time?  How much? (This relates to #2)
I would probably say it takes the same time as Perceive in Detail, so a Simple Action to make one test. If you are trying to search an area or perceive in critical detail, then it would take longer just like looking in the physical world.

[Reaver]

1:
This depends. There is not a "eye" icon like in Skyrim that tells you if you are noticed of not, regardless of where the "viewer" is
If the astral infiltrator can see who is observing him, we would be able to notice that that entity is astrally active (Auras of dual natured, and astrally perceiving are more noticeable).. But you never "know" if your hiding attempt worked or not... usually until its too late

2: I use the Asensing  skill for astral preception at my table, however, some GMS use good ol' regular Perception tests for this, and Asensing when you want more detail then just base line "Mundane/awakened/astral construct Aura" level of info.

3: If you can see them, you can asense them. if you are trying to be "cute" and say "NO!! you just saw my big toe only!!" type of argument, then the argument is "did you see them"... which is upto the GM... These things are generally a binary YES/NO - PASS/FAIL thing... not a "you only saw 1% thus you can only get 1% info" type of thing..

4: again, hard to say. To astrally perceive, you don't use your eyes... A person can be staring into a newspaper while astrally observing BEHIND him.. But the astral perceiver does incur a -2 modifer to ALL actions in the meat while astrally observing, so there maybe tells for someone to notice (Perception test time?) if the observer is trying to combine actions (astrally perceive while navigating traffic for example)

5: its effectively a perception test... so roughly the same amount of time as a Perception check... So anywhere from a simple to an extended action, depending on what situation.   

[Marcus]

1) Is it obvious or perceivable that your Astrally Perceiving? (By someone mundane or not perceiving/astral)
You're staring at something. That's it. Someone who knows you can do it, might guess you are, but you might just also be checking out that sweet ride, be distracted by someone hot, or in AR society just be distracted by cool AR meme or jingle. In an AR accustomed society staring off into space is probably fairly normal behavior.

2) It seems that "Astral Perception" and Assensing" are the same roll so you use your Assensing roll for the hiding aura
Astral Perception is the act of seeing the aura, Assensing is reading the aura. Seeing the Writing on page is not the same as reading the writing on the page. They aren't really the same. You could Perceive astral without Assensing someone. There are things to see in Astral.

3) How much can do you allow to be seen just by perceiving an aura?
So perceiving astral is like looking at the forest. You see a lot of trees. It doesn't tell you anything until you start focusing down.
But it will tell you stuff like, what's over there. Presence of Spirit, Wards, Mana barriers, Magic Amor probably, Non-normal BGC, Voids, General Emotional tone of the area. Folks with the bright aura flaw, Anything that weird would probably stand out.

4) Is it obvious you are assensing something? (Are you "staring" at it)? And is it obvious/not on both planes?
See above on 1. Someone actively astrally watching, you could probably tell when you went dual natured, I'd give'em a roll. But from general observation no. All they would see is the character looking at something.

5) When you assense does it take time?  How much? (This relates to #2)
If you just looking at one person it should fast, if your taking time to study a whole area, it could be awhile. I'd go with Kiir on that.

Edit: Stupid phones.

[BeCareful]

They seem the same, but the way I think of it, "Astral Perception" is just generally looking around on the Astral Plane, while Assensing is focusing in on something specific. Similarly to how you can notice everything obvious around you, but have to spend a simple action and make Perception when you're examining or looking for something.

As for the other stuff, since it isn't spelled out, it's definitely something upon which players & GMs should agree. Though even if Astral Perception/Assensing isn't obvious, I do like the idea of magicians that make it obvious. Either because they have to as part of their contracts, or they just have a flair for the dramatic. Have the psychic-looking magician do a gasp-filled aura reading! Have that assensing nun thrust out her crucifix and shout, "Detect Evil!" See how the PCs react!