← Another date

Birthday · April 16, 2015

One-Armed Spiral Galaxy NGC 4725

April 16, 2015

Every year, the Earth returns to the same point in its orbit where it was when you were born.

One-Armed Spiral Galaxy NGC 4725

A little universe, just for you

Your date.
Ready to give.

Free PNG · 1080 × 1350 · No account needed

Image rights and credit requirements apply when sharing or reusing imagery.

Change the year

APOD published April 16, 2015. Credit: Martin Pugh. A publication-date match, not a photo taken on your date. Independent of NASA.

Behind the image

One-Armed Spiral Galaxy NGC 4725

Original APOD · April 16, 2015

While most spiral galaxies, including our own Milky Way, have two or more spiral arms, NGC 4725 has only one. In this sharp color composite image, the solo spira mirabilis seems to wind from a prominent ring of bluish, newborn star clusters and red tinted star forming regions. The odd galaxy also sports obscuring dust lanes a yellowish central bar structure composed of an older population of stars. NGC 4725 is over 100 thousand light-years across and lies 41 million light-years away in the well-groomed constellation Coma Berenices. Computer simulations of the formation of single spiral arms suggest that they can be either leading or trailing arms with respect to a galaxy's overall rotation. Also included in the frame, sporting a noticably more traditional spiral galaxy look, is a more distant background galaxy.

Image credit: Martin Pugh

Explore April 16 in other years