The scales of Raga Bhairavi are as follows :
Aarohanam (Ascending) : S G2 R2 G2 M1 P D2 N2 S’
Avarohanam (Descending) : S’ N2 D1 P M1 G2 R2 S
Bhairavi is a janya raga, derived from Natabhairavi (see below), 20th on the Melakarta scale.
The Raga uses D2 in Aarohanam and D1 in Avarohanam. Please note that the Carnatic Bhairavi is not related to the Hindustani Bhairavi. It is a heavy raga, used often as the backbone of a concert. There are many compositions in this raga; some of the well known ones are like Viriboni varnam by Pacchimiriam Adiyappa, Upacharamulanu and Raksha Bettare by Tyagaraja, Balagopala by Muthuswami Dikshithar, Yaaro Ivar Yaaro by Arunachala Kavi and a beautiful Swarajati by Shyama Shastri – Kamakshi Anudinamu.
Tamil speakers may enjoy Charulata Mani’s presentation of Bhairavi below:
Note : The 12 notes in the octave are named as below. Please note that C is used as Sa for the sake of simplicity as the scale is relative in Carnatic Music. Also note that the scales paint only a superficial picture of the raga as the gamakas(ornamentations) are a very important part of a raga.
Music To My Ears 
The N oscillation in aroha sounds like S D2 S D2 ( D2 = N 1) . I found some musicians singing the N note in a sruti between D2 and N2 ( oscillation is like N2D2 N2D2) while singing M1 N D1 P. So even two versions of N.
Just to bring to your attention.. In Ganamrutha Varna malika by A. Panchapakesa Iyer the N is given as N 1 or D2 both in aroha and avaroha
Hi Purnima, sorry for late reply – I didn’t get a notification like I normally do.
About Bhairavi, there seem to be a few variations, aren’t there. Sadly, I am not really well-enough educated in CM to discuss this point! I have seen others mention the N1 like you say. See here https://medium.com/emergent-phenomena/raga-bhairavi-in-carnatic-music-ce9702941893
Cheers. Suja