Social media stars and sporting champions are splashing the cash for Australian bushfire relief efforts and urging fans to do the same. Twenty-six people have died since the start of the disaster in September, more than 2,000 homes have been destroyed, and some eight million hectares (80,000 square kilometres) has burned -- an area roughly the size of Ireland or South Carolina. Australian Marvel actor Chris Hemsworth said he would donate AUS$1 million, singers Kylie and Danni Minogue pledged AUS$500,000 to the country's rural firefighters, a donation matched by Nicole Kidman and her husband Keith Urban. Compatriots including Russell Crowe -- who used his Golden Globe win to speak about the tragedy -- and Rebel Wilson have pledged donations, with singer Dami Im also donating. Athletes like Lewis Hamilton, tennis players Ashleigh Barty, Maria Sharapova and Novak Djokovic, and cricketers -- including Chris Lynn and Glenn Maxwell -- offered to donate their winnings. On Wednesday, organisers of the Australian Open said Roger Federer, Williams and Rafael Nadal will headline a charity match ahead of the tournament. Many celebrities will auction clothes: Williams is donating a signed dress, while British actor and writer Phoebe Waller-Bridge announced her Golden Globes suit would be auctioned off, and Shane Warne sold his baggy green cap to an anonymous bidder for AUS$1 million. American stars -- including Kylie Jenner, singers Pink, Lizzo, and Shawn Mendes, talkshow host Ellen DeGeneres, and actor Patricia Arquette -- all pledged to contribute to relief efforts. Leonardo DiCaprio's environmental group, Earth Alliance, also said it was giving US$3 million. Elton John announced during a performance on Tuesday he would donate $1 million, and Metallica said they would give $500,000 to the county's fire service. Celebrities such as Margot Robbie, Naomi Watts, Hugh Jackman, and Selena Gomez also announced they had donated but declined to state how much. burs-rbu/je