Multiple subsequent studies found that the planetary signal in fact originates from stellar activity, and thus the planet does not exist,[4][5][6][7][8] but this remains disputed.

Udry's team employed the radial velocity technique, in which the minimum mass of a planet is determined based on the small perturbations it induces in its parent star's orbit via gravity.

[3][2] In September 2012, Roman Baluev filtered out the "red noise" from the Keck data and concluded that this planet's existence is probable only to 2.2 standard deviations, and thus is uncertain.

[14] Earlier that same year, however, S. S. Vogt (USNO), together with R. P. Butler and N. Haghighipour, published a study that supported the existence of the planet with a much higher probability;[15] they also pursued a dynamical analysis of the system.

Additional work on Gliese 581 as a four-planet system (thus, including planet d), demonstrating its long-term orbital stability, was given by Makarov and coauthors.

[24] Evidence based on a 2022 paper confirmed the results of previous studies suggesting that the announcement of Gliese 581d stems from a false detection due to stellar activity.

Because Gliese 581d was believed to orbit outside the habitable zone of its star it was originally thought to be too cold for liquid water to be present.

With the 2009 revised orbit, climate simulations conducted by researchers in France in 2011 indicated possible temperatures suitable for surface water at sufficient atmospheric pressure.

[10][35] If Gliese 581d exists, it would be the first super-Earth identified to be located in a habitable zone outside of the Solar System, according to work published in 2007.

[10][11] As part of the 2009 National Science Week celebrations in Australia, Cosmos magazine launched a website called "Hello from Earth" to collect messages for transmission to Gliese 581d.

The messages were transmitted from the DSS-43 70 m radio telescope at the Canberra Deep Space Communication Complex at Tidbinbilla, Australia, on 28 August 2009.