Questions with arc in the answer can you please help with 4 answers

[loobylooo]

I am struggling with four questions in a quiz that I am doing and would be grateful for any help please. All the answers include the letters “arc” in that order,
Questions:
Audible computer signal (6)
Bright star (8)
New to old moon (5,5)
Small exclusive ruling class (9)

I do hope that someone can help and I would be very grateful.
Thank you
loobyloo

[piggling]

4 hierarchy

[bibblebub]

2 Arcturus

[factor-fiction]

oligarchy?

[bibblebub]

4 oligarchy ?

[factor-fiction]

lunAR Cycle

[loobylooo]

Thank you those of you who have posted answers so far, factor30, piggling and biblebub, I am very grateful, how thick am I not getting Lunar cycle, the other well that was a little harder :-))

I am just looking for two answer now. Answers still with "arc" in that order in.
Audible compueter signal (6)
Bright star(8)

Thanking you and hoping
loobyoo

[factor-fiction]

Arcturus is your bright star

[factor-fiction]

I prefer oligarchy to hierachy

[loobylooo]

Whoops!!! sorry Biblebub got your answr for Bright Star, thank you, just the Audible computer signal (6) one now, thank you once again all of you
loobylyy

[loobylooo]

Yes I agree on both of your opinions factor30 thank you

[cupid04]

arcturus

[loobylooo]

Is anyone out there still with me? Thank you for all of your answer sorry for my typing mistakes, one arm in plaster at the moment and I am new to this sort of thing.
Just looking for the one answer now please.

Audible computer signal (6) with arc in the answer

Thank you
loobyloo

[factor-fiction]

I'm struggling. I'm assuming it's a word not an acronym. I can think of words like PARCEL and SEARCH but can't link them to the clue!

[Fibonacci]

Earcon?

[loobylooo]

At the beginning of the questions it just says all the answers include the letters “arc” in that order e.g. tree (5) larch so I don’t think it would be an acronym. I think I may go with Fibonacci answer Earcon if nothing else comes up. Thank you Fibonacci and thank you Factor30 I will keep looking in case someone else posts.
Thanks to all
loobylooo

[loobylooo]

Thank you Fibonacci I am going to go with Earcon I am very grateful for your help.
Regards
Loobyloo