SOURCE

<div class='box'>
  <div class='star'>
  </div>
</div>

body,
html {
  height: 100%;
}

.box {
  width: 100%;
  height: 100%;
  background: #f0f;
  position: relative;
}

.star {
  width: 40px;
  height: 5px;
  background: linear-gradient(to right, rgba(225, 255, 255, 1) 1%, rgba(225, 255, 255, 1) 5%, rgba(255, 255, 255, .1));
  border-radius: 50% 100% 100% 50%;
  position: absolute;
  top: 50px;
  right: 50px;
  animation: move 1s linear infinite;
}

.star:after {
  content: '';
  width: 5px;
  height: 5px;
  background: #ff0;
  position: absolute;
  top: 0;
  left: 0;
  border-radius: 50%;
}

@keyframes move {
  0% {
    right: 50px;
  }
  100% {
    right: 400px;
  }
}