It was a week for celebration! Lance Bass and Irina Shayk helped the ASPCA aid rescued animals at the Young Friends Benefit, pop music queens Selena Gomez and Demi Lovato marked the release of their new albums, and Lupita Nyong'o debuted her latest play in Dior. Click through to find out what else happened this week!
October 18: Reese Witherspoon and Renee Zellweger came together for the Walk to Defeat ALS on behalf of former publicist Nanci Ryder, who is battling with the ALS.
Photo: Frazer Harrison/Getty Images
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October 18: Chris Hemsworth supported younger brother Liam at his premiere for 'The Dressmaker' in Melbourne.
Photo: Getty Images
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October 18: Number one fan! Demi Lovato cheered on the New York Jets with owner Woody Johnson's wife Suzanne Johnson at MetLife Stadium in East Rutherford, NJ.
Photo: StarTraks Photo/Michael Simon
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October 17: Selena Gomez had a fright at Knott's Scary Farm in Buena Park, California.
Photo: Getty Images
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October 17: HAIM performed "Hava Nagila" for James Franco at Hilarity for Charity's Variety Show: James Franco’s Bar Mitzvah benefiting the Alzheimer’s Association presented by Funny Or Die and go90.
Photo: Tyler Curtis /ABImages
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October 17: Gwyneth Paltrow brought her son Moses (not pictured) to the Veuve Clicquot Polo Classic in Pacific Palisades, California.
Photo: Getty Images
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October 17: Flower power! Miley Cyrus wore a floral ensemble to James Franco's Bar Mitzvah - Hilarity For Charity's fourth annual variety show in L.A.
Photo: WireImage
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October 17: Jude Law spoke to a full audience during Jude law attends a meeting with spectators during the Rome Film Festival.
Photo: Tiziana Fabi/AFP/Getty Images
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October 17: Lauren Conrad was certainly cheery in yellow at the Veuve Clicquot Polo Classic at Will Rogers State Historic Park in Pacific Palisades, California.
Photo: WireImage
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October 17: Bethany Mota greeted fans at BeautyCon in NYC
Photo: Getty Images for BeautyCon NYC
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October 17: Jaime King, Kyle Newman and James Knight made it a family affair at the Veuve Clicquot Polo Classic in Pacific Palisades, California.
Photo: Getty Images
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October 16: Sophia Bush was masked to perfection at the UNICEF Neverland Masquerade Ball at Moonlight Studios in Chicago.
Photo: Getty Images
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October 15: Joe Jonas took a break from DNCE to hang out at the Disaronno Wears Cavalli launch event at Milk studios in New York City.
Photo: Getty Images
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October 15: Puppy love! Irina Shayk hosted the 2015 ASPCA Young Friends Benefit in New York City.
Photo: Getty Images
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October 15: Busy Phillips was rocker chic during the 'All Things Must Pass' premiere party in L.A. where Eagles of Death Metal performed.
Photo: Eric Charbonneau/Le Studio Photography
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October 15: Lance Bass posed with a furry companion on the event's orange carpet.
Photo: Getty Images
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October 15: Hollywood for a cause! Sutton Foster and her co-host Irina with the ASPCA's President Matthew Bershadker.
Photo: Getty Images
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October 15: Kate Hudson, Neil Patrick Harris, Anna Wintour and Michael Kors came together during the Golden Heart Awards in New York City.
Photo: Getty Images
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October 15: Looking good, Leo! Leonardo DiCaprio took the stage during the Directors Guild of America Honors in New York City.
Photo: Getty Images
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October 15: Demi Lovato showed her confidence to New York City during a street performance in Times Square.
Photo: Getty Images
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October 15: And you get a smile! Oprah Winfrey worked the crowd on her way to 'The Late Show with Stephen Colbert' in New York City.
Photo: Getty Images
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October 15: Girl power! Lena Dunham and Sia attended the Gem's 2015 Love Revolution Gala in New York City.
Photo: Getty Images
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October 15: Welcome home! Tracy Morgan made a grand entrance into New York City's NBC building for his 'Saturday Night Live' rehearsal.
Photo: Getty Images
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October 15: This lady knows shoes! Fergie gave some lucky fans a preview of her shoe collection at Lord and Taylor's NYC location.
Photo: Bryan Bedder, Getty
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October 15: Sean "Diddy" Combs and Scooter Braun hosted the FCancer Celebration event during the Revolt Music Conference in Miami.
Photo: WorldEye
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October 14: Selena Gomez and Emily Blunt spent some time backstage after Broadway's 'Hamilton'.
Photo: Getty Images
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October 14: A girl on a bike! Katherine Heigl was caught filming her new show 'Doubt' in New York City.
Photo: Getty Images
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October 14: Michael Strahan and Gabrielle Union had some fun during AOL's BUILD event in New York City.
Photo: Getty Images
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October 14: Carrie Underwood enjoyed some photo fun with her mother and "sweet" aunt during her 'Storyteller' listening party at The Standard in Nashville.
Photo: Instagram/@carrieunderwood
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October 14: Lupita Nyong'o was a vision in Dior during opening night of her new play 'Eclipsed' at the Public Theatre in New York City.
Photo: Getty Images
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October 14: Sarah Hyland looked stunning during the No Kid Hungry fundraiser at the Four Seasons in Beverly Hills, California.
Photo: Getty Images
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October 14: Rachel Bilson took the stage during the No Kid Hungry party.
Photo: Getty Images
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October 13: No ghost here! Jessica Chastain, Tom Hiddleston and Mia Wasikowska stood in front of the Victorian-themed window display at Bergdorf Goodman in NYC, inspired by their thriller 'Crimson Peak'.
Photo: Getty Images
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October 13: Nick Cannon celebrated his 35th birthday with a DJ set at NYC hotspot Avenue.
Photo: Menbar Photos
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October 13: Hello, ladies! Gwyneth Paltrow and Nicole Ritchie looked sexy in black during La Mer's Celebration of an Icon bash in Los Angeles.
Photo: Michael Simon, StarTraksPhoto
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October 13: Look at her glow! Chrissy Teigen made her first post-pregnancy announcement appearance during the La Mer's Celebration of an Icon party.
Photo: Michael Simon, StarTraksPhoto
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October 13: Sweet success! 'The Voice' champion Cassadee Pope celebrated the release of her new single 'I Am Invincible' in New York City.
Photo: Michael Simon
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October 12: Olivia Culpo looked chic in stripes at Cosmopolitan's 50th birthday celebration.
Photo: Getty Images
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October 12: Cosmopolitan's first family, the Kardashian-Jenner clan, also joined in the fun.
Photo: Getty Images
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October 12: Kelly Ripa and Mark Consuelos' kids looked all grown up during Kelly's Hollywood Walk of Fame ceremony in Los Angeles, California.
Photo: Getty Images
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October 12: Good for you! Selena Gomez kicked off her fashionable week in New York City – and the release of her latest album 'Revival' – with a performance on the 'Today' show.
Photo: Getty Images
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October 10: Eva Longoria joined Pussycat Dolls founder Robin Antin for her PCDFit Dance Camp at the Hard Rock Hotel Riviera Maya.
Photo: FingerPrint Communications