So, Wolf 1069 is a red dwarf in the constellation Cygnus. The star is very close to Earth at a distance of 9.6 pc [1, 2], and while this isn't close enough to place the red dwarf in a list of the top 50 closest star systems, it is close enough for me to use my Star Wars sound effects. Also, astronomers have found an exoplanet orbiting it that is a candidate for harboring life [3]. Also, if this all sounds rather familiar, that's because, seven episodes ago, I discussed another red dwarf named GJ 887 that was also very close to the Earth and that also had exoplanets orbiting it. I have considered that, after doing this podcast for a while, I would end up talking about the same type of objects over and over again, and I'm not talking about just supermassive black holes and binary star systems but really really specific things like, well, really nearby red dwarfs with exoplanets that could potentially harbor life. Anyhow, I will promise that Wolf 1069 will be different from GJ 887.
However, before I discuss the exoplanet, let's talk a little bit about the star itself. Wolf 1069 is named after Max Wolf, and yes, his name really was Max Wolf, and he apparently used that name both in his personal and professional life, although his full name was Maximillian Franz Joseph Cornelius Wolf. Anyway, Max Wolf was a German astronomer who pioneered the use of photography in astronomy in the late nineteenth century, and through his use of photography, he discovered a couple hundred asteroids as well as dark nebulae [4, 5]. In 1919, he began publishing a series of catalogs of stars so close to the Earth that they could be seen moving slightly relative to background stars (albeit very slowly and over a period of several years), and Wolf 1069 was in one of those catalogs [6].
The star has a mass of 0.17 times the mass of the Sun and a radius of 0.18 times the radius of the Sun [3]. The total energy output from the red dwarf is 0.029 times the Sun's [3]. Consequently, although the star is close, it's really hard to see. It only has an apparent magnitude of somewhere between 12 and 16 depending on which part of the spectrum you look at, which means that it's too faint to see without a telescope, and even with a telescope, it would look indistinct compared to everything else.
The exoplanet, which is formally designated Wolf 1069b, was found using a series of observations spanning from 2007 to 2020, with the discovery published in 2023 by a group led by Diana Kossakowski [3]. The group was able to identify that the star moved back and forth in a periodic way that was consistent with the star being orbited by and gravitationally affected by an exoplanet. In some cases, observations that take a decade or more would be needed to demonstrate that an exoplanets with a very long orbital period is circling another star. For example, if an exoplanet in another star system takes 10 years to complete an orbit, it would take 20 years of observations (or 2 of the exoplanet's orbits) to definitely show that the star is moving in a way that is consistent with the presence of a planet in the star ssytem. In Wolf 1069's situation, however, the exoplanet completes an orbit once every 15.564 days (or 15 days, 13 hours, and 32 minutes) [3], which would take just a few weeks of observing to find. However, I think the reason why it took so long to identify that a planet orbited Wolf 1069 is because the star is faint and the exoplanet is also relatively small, which meant that the gravitational effects that astronomers were looking for were also very small, and to find those effects, they needed a lot of data.
So let's do a quick rundown of some numbers for the exoplanet Wolf 1069b. First of all, the exoplanet has a mass of 1.26 times the Earth's mass [3], which in exoplanet terms means that Wolf 1069b is remarkably Earth-like in size. The exoplanet orbits at a distance of 0.067 Astronomical Units from its host star [3], which is equivalent to roughly one-sixth the distance from our Sun to Mercury. This is close, but because the faint red dwarf is indeed faint, the average temperature on the surface of the exoplanet is estimated to be -23 degrees Celsius [3], which is below freezing, but this makes it possible that life may live on the warmer parts of the surface. (Also, this estimate ignores any atmospheric greenhouse effect that would make the exoplanet warmer, which means that it could host liquid oceans instead of mostly ice on its surface.)
So now let's return to the one big reason why Wolf 1069 is not exactly the same as GJ 887, which as a reminder is another nearby red dwarf with exoplanets that I discussed seven episodes ago. People were also really excited about the prospect of possibly finding life on one of the exoplanets in the GJ 887 system [7] except that, in follow-up ultraviolet observations after the discovery of the exoplanets, they found that GJ 887 has really strong stellar flares [8], and these types of stellar flares are capable of baking away the outer atmospheres of exoplanets, leaving nothing but roasted dry planetary surfaces behind. This was such a let down that I'm certain that someone from the original research group who found GJ 887's exoplanets later sought psychological counselling.
However, Wolf 1069 is different. That giant heap of data that Diana Kossakowski and her collaborators accumulated over 13 years allowed her group to determine that Wolf 1069 does not exhibit any strong flaring [3]. (They even checked different parts of the electromagnetic spectrum to make sure that the flares weren't hidden somewhere like in X-ray emission.) This lack of flaring means that it is much more likely that the exoplanet Wolf 1069b has an atmosphere, which then means that it's more likely that the exoplanet harbors life.
This discovery is a very new one (as of when I am recording this in 2025), so it doesn't look like anyone has had the chance to publish any detailed follow-up observations or analyses yet, but I'm sure that the exobiology people are going to be especially interested in taking a closer look at the Wolf 1069 system to see if they can find any signs of water or other hints of life on the system's exoplanet.