how is the '*' used in dereferrence from array in kotlin?

Question

Looking at one kotlin sample from https://github.com/googlesamples/android-topeka/

see the ‘*’ is to used for getting the first element from an array, 

does anyone know from where it is explained?

val pairs = TransitionHelper.createSafeTransitionParticipants(activity, true,
                Pair(v, activity.getString(R.string.transition_avatar)))
val options = ActivityOptionsCompat.makeSceneTransitionAnimation(activity, *pairs)

the TransitionHelper:

package com.google.samples.apps.topeka.helper

import android.annotation.TargetApi
import android.app.Activity
import android.os.Build
import android.support.annotation.IdRes
import android.support.v4.util.Pair
import android.view.View

/**
 * Helper class for creating content transitions used with [android.app.ActivityOptions].
 */
object TransitionHelper {
/**
 * Create the transition participants required during a activity transition while
 * avoiding glitches with the system UI.

 * @param activity The activity used as start for the transition.
 *
 * @param includeStatusBar If false, the status bar will not be added as the transition
 * participant.
 *
 * @return All transition participants.
 */
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
fun createSafeTransitionParticipants(activity: Activity,
                                     includeStatusBar: Boolean,
                                     vararg others: Pair<View, String>
): Array<Pair<View, String>> {
    // Avoid system UI glitches as described here:
    // https://plus.google.com/+AlexLockwood/posts/RPtwZ5nNebb

    return ArrayList<Pair<View, String>>(3).apply {
        if (includeStatusBar) {
            addViewById(activity, android.R.id.statusBarBackground, this)
        }
        addViewById(activity, android.R.id.navigationBarBackground, this)
        addAll(others.toList())

    }.toTypedArray()
}

@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private fun addViewById(activity: Activity,
                        @IdRes viewId: Int,
                        participants: ArrayList<Pair<View, String>>) {
    val view = activity.window.decorView.findViewById<View>(viewId)
    view?.transitionName?.let { participants.add(Pair(view, it)) }
}

}