There isn't a specific, universally accepted name for the first ray of light. However, depending on the context, you could use these phrases:

* First light: This is a common term used in astronomy and photography, referring to the first time a telescope or camera is used to observe an object.

* Dawn's first light: This is a poetic term that refers to the first light of the sun breaking over the horizon.

* Golden hour: This refers to the first hour after sunrise and the last hour before sunset, when the light is warm and golden.

* The breaking of dawn: This is another poetic term that refers to the moment when darkness begins to give way to light.

The most appropriate term will depend on the specific situation and the desired tone.