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My July fund-raising campaign, celebrating the 13th anniversary of the start of this website, has now ended. This was the second most successful monthly fund-raising campaign ever. Thank you again to everyone who has who donated or subscribed. It is difficult to explain what your support means to me.


You can still donate or subscribe to support my work if you wish, either by giving a one-time contribution or a regular subscription. There are four ways of doing so:


1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.


2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.

3. A Paypal Donation:

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5. Donate by check, payable to Robert Zimmerman and mailed to
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Hubble captures shadows on star’s outer accretion disk cast by inner accretion disk

Shadows cast on star's accretion disk
Click for original image.

Astronomers using the Hubble Space Telescope’s images taken five years apart have captured the changing shadows cast by a star’s inner accretion disk onto its outer accretion disk.

Those images are to the right, reduced and rearranged to post here. From the caption:

Comparison images from the NASA/ESA Hubble Space Telescope, taken several years apart, have uncovered two eerie shadows moving counterclockwise across a disc of gas and dust encircling the young star TW Hydrae. The discs are tilted face-on as seen from Earth and so give astronomers a bird’s-eye view of what’s happening around the star.

The [top] image, taken in 2016, shows just one shadow [A] at the 11 o’clock position. This shadow is cast by an inner disc that is slightly inclined to the outer disc and so blocks starlight. The picture on the [bottom] shows a second shadow that emerged from yet another nested disc at the 7 o’clock position, as photographed in 2021. What was originally the inner disc is marked [B] in this later view.

The shadows rotate around the star at different rates like the hand on a clock. They are evidence for two unseen planets that have pulled dust into their orbits. This makes them slightly inclined to each other. This is a visible-light photo taken with the Space Telescope Imaging Spectrograph. Artificial colour has been added to enhance details.

An artist’s conception of the system, as seen from an oblique angle, is available here. All told, this solar system of disks kind of resembles a spinning gyroscope, with its different rings tilted at different angles to conserve angular momentum.

Genesis cover

On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.

The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.

The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.

"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News


  • GaryMike

    What is being described by you may be what it actually is.

    I’m defaulting to it being just another Rorschach test, pending conformation.

    I can visualize what you’ve described, but I’m not imagining certain interpretation.

    I’ve been an irritant before.

  • Star Bird

    So at least Hubble is still there sending back photos of deep space but no signs of the Jupiter 2

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