APOD: 2021 June 24 - Messier 99 Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 June 24 Messier 99 Image Credit: NASA, ESA,Hubble, Janice Lee; Processing & Copyright: Leo Shatz Explanation: Grand designspiral galaxy Messier 99looks majestic on a truly cosmic scale.This recently processedfull galaxy portraitstretches over 70,000 light-years across M99.The sharp view is a combination of ultraviolet, visible,and infrared image data from the Hubble Space Telescope.About 50 million light-years distant toward the well-groomedconstellation Coma Bernices, the face-on spiral is amember of the nearbyVirgo Galaxy Cluster.Also cataloged as NGC 4254, aclose encounterwith another Virgo cluster member has likelyinfluenced the shape of its well-defined, blue spiral arms. Tomorrow's picture: single shot Andromeda<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights apply.NASA WebPrivacy Policy and Important NoticesA service of:ASD atNASA /GSFC& Michigan Tech. U.

APOD: 2021 June 23 - STARFORGE: A Star Formation Simulation Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. STARFORGE: A Star Formation Simulation Video & Text Credit: Michael Y. Grudić (Northwestern U.) et al., STARFORGE Collaboration; Music: Prelude, Op. 28, No. 4 in E Minor (Frédéric Chopin) Explanation: How do stars form? Most form in giant molecular clouds located in the central disk of a galaxy. The process is started, influenced, and limited by the stellar winds, jets, high energy starlight, and supernova explosions of previously existing stars.The featured video shows these complex interactions as computed by the STARFORGE simulation of a gas cloud 20,000 times the mass of our Sun.In the time-lapse visualization, lighter regions indicate denser gas, color encodes the gas speed (purple is slow, orange is fast), while dots indicate the positions of newly formed stars.As the video begins, a gas cloud spanning about 50 light years begins to condense under its own gravity. Within 2 million years, the first stars form, while newly formed massive stars are seen to expel impressive jets.The simulation is frozen after 4.3 million years, and the...

APOD: 2021 June 22 - HD 163296: Jet from a Star in Formation Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 June 22 HD 163296: Jet from a Star in Formation Image Credit: Visible: VLT/MUSE (ESO); Radio: ALMA (ESO/NAOJ/NRAO) Explanation: How are jets created during star formation?No one is sure, although recent images of the young star system HD 163296 are quite illuminating.The central star in the featured image is still forming but seen already surrounded by arotating disk and anoutward moving jet.The disk is shown in radio waves taken by the Atacama Large Millimeter Array (ALMA) in Chile, and show gaps likely created by the gravity of very-young planets. The jet, shown in visible light taken by the Very Large Telescope (VLT, also in Chile), expels fast-moving gas -- mostly hydrogen -- from the disk center. The system spans hundreds of times the Earth-Sun distance (au). Details of these new observations are being interpreted to bolster conjectures that the jets are generated and shaped, at least in part, by magnetic fields in the rotating disk.Future observations of HD 163296 and other similar star-forming...