Full Wallpaper View: 1920x1280

Another view of my purely fictional planet: A clear, almost cloudless and hot day on an island in a big lake, covered with a primitive, moss-like vegetation, without animal life. This planet is younger than earth, some simply animal life exists only in the depths of the waters.
Most of the light and radiation comes from the sunlike part of this binary star system.
The weaker part, a Red Dwarf is just being obscured by an also earth-sized „sister-planet” circling with this planet in the same orbit.
I don’t know for sure if this scenario is possible (regarding huge tides, tidal locking, unstable orbits etc.), but nevertheless, I’ve taken the „artistic freedom” to supposing it.

Made with Terragen 3.3 and Pixelmator.

Very good. Much better.

Binary planets are quite possible, although they would probably be tidally locked to each other, giving longer days than Earth has.  Put another Earth where the Moon is and our days would be about a month long.  Not pleasant for us, but life would be possible, and native life wouldn't find it a problem.  As for tides, the two planets would have large tides, but since they are locked to each other, the tides would stay in the same place.  In other words, the planets would be distorted a little, rather than perfectly round, but it wouldn't be noticeable on the ground.  Solar tides would be about the same as on Earth, but move much slower, due to the slow rotation.

From the light angles, the red dwarf is probably in a distant orbit.  Even as close as Jupiter it wouldn't be a problem for your planet's orbit around the primary, which should be about as far away as the Sun is from the Earth.  At that distance the extra heat would be negligible, and again, the native life would have evolved with bright nights.  It wouldn't have any noticeable effect on tides.

So, a very possible system, and an interesting one to explore.

Thank you for your explanations regarding "Binary planets". Something like this I had in mind for this render, now you gave some plausible facts.