Mergers and Acquisitions

In this image, galaxy NGC 2799 appears to being pulled into the center of its neighbor NGC 2798. Interacting galaxies such as these may eventually merger or form a unique pairing. For now, stars from NGC 2799 seem to be falling into NGC 2798 almost like droplets of water.

Galactic mergers usually take place over time scales of several hundred million to a billion or more years. While one or both of the galaxies may cease to exist as an independent entity, the vast space between stars means that stellar collisions are unlikely, so the individual stars typically drift past each other. Our Milky Way is on track to merge with the Andromeda galaxy in four billion years or so.

Image Credit: NASA / ESA

NGC 3310

NGC 3310NGC 3310 is a grand design spiral galaxy in the constellation Ursa Major. It is also a starburst galaxy. (Starburst galaxies are undergoing an exceptionally high rate of star formation.) NGC 3310 probably collided with one of its satellite galaxies about 100 million years ago, triggering widespread star formation. The ring clusters of NGC 3310 have been undergoing starburst activity for at least the last 40 million years.

Image Credit: NASA / ESA

Mergers and Acquisitions

NGC 2623 is really two galaxies that are merging to become one. The pair lies some 300 million light-years distant toward the constellation Cancer. The are in the final stages their merger. The violent encounter between two galaxies that once may have been similar to our Milky Way has resulted in widespread star formation near a luminous core and along tidal tails. The opposing tidal tails extend more than 50,000 light-years from the combined nucleus and are filled with dust, gas, and young blue star clusters. Accretion by a supermassive black hole drives the activity near the nucleus. Star formation and the active galactic nucleus cause NGC 2623 to shine brightly across the spectrum.

BTW, in about 4 billion years, our galaxy, The Milky Way, will merge with the Andromeda Galaxy.

Image Credit: NASA / ESA

An Infrared View of the Trifid Nebula

The Trifid Nebula, aka M20, is easy to find with a small telescope. It’s a well known object in the nebula rich constellation Sagittarius. Visible light pictures show the nebula divided into three parts by dark, obscuring dust lanes, but this infrared image reveals filaments of luminous gas and newborn stars. This false-color view was taken by the Spitzer Space Telescope. The Trifid is about 30 light-years across and around 5,500 light-years away.

Image Credit: NASA

Objects In The Mirror Are Closer Than They Appear

When I look at the star Betelgeuse through my backyard reflecting telescope, it appears to be a reddish-orange point of light. Phys dot org reports the star is smaller and closer than we previously thought. Because it is beginning to show signs that it might go supernova, we don’t want to be too close. It might hold off for 100,000 years, or it may already have blown up.

The new estimate for the distance to Betelgeuse is 530 light-year. That’s probably a safe distance, but the light show will be impressive when it comes.

NGC 4414, An Unbarred Spiral Galaxy

ngc-4414NGC 4414 is an unbarred spiral galaxy about 62 million light-years away in the constellation Coma Berenices. It has short segments of spiral structure but lacks the dramatic well-defined spiral arms of a grand design spiral galaxy. NGC 4414 is also a very isolated galaxy without signs of past interactions with other galaxies.

Image Credit: NASA / ESA

NGC 300

ngc 300NGC 300 is a spiral galaxy in the constellation Sculptor. At one time, it was thought that NGC 300 was a part of a galaxy cluster know as th eSculptor Group. However, recent measurements show that it is closer to us in the relatively empty space between our Local Group and the Sculptor Group. It’s about 94,000 light-years in diameter, somewhat smaller than the Milky Way

Image Credit: ESO

The Milky Way

milkwayThis 360-degree panorama covers all of the southern and northern celestial hemispheres. The plane of our Milky Way Galaxy, which we see edge-on from Earth, is the luminous band across the image. The projection used in the picture puts the viewer in front of our Galaxy with the Galactic Plane running horizontally through the image. It’s almost as if we were looking at the Milky Way from the outside because the solar system is near the galactic rim. From our vantage point the general components of our spiral galaxy come clearly into view, including its disc as well as the central bulge and nearby satellite galaxies.

Image Credit: ESO / S. Brunier

A Dwarf with a Supermassive Black Hole

A dwarf starburst galaxy about 30 million light years from Earth.Henize 2-10 is a dwarf galaxy, and it is the first dwarf galaxy ever discovered to contain a supermassive black hole at its center. This was surprising because the black hole is about one quarter of the size of the one at the center of the Milky Way Galaxy. However, Henize 2-10 is only about1/1,000th the size of the Milky Way..

This image combines x-ray (Chandra), visible light (Hubble), and radio telescope (Very Large Array) views.

Image Credit: NASA / NRAO

Zooming in on a Supernova

This video zooms into the galaxy catalogued as NGC 2525. The Hubble Space Telescope captured a series of time-lapse images of a supernova in that galaxy in 2018. It appears as a very bright star located on the outer edge of one of the spiral arms. The supernova initially outshining the brightest stars in the galaxy, but it fades into obscurity during the year of observations.

Video Credit: ESA


On  23 April, 2014, the rising tide of X-rays from a superflare on red dwarf DG CVn triggered the Swift satellite’s Burst Alert Telescope (BAT). The satellite turned to observe the source in greater detail with its other instruments and notified astronomers around the globe that a powerful outburst was in progress.

BTW, my principal contribution to the Swift satellite was the design and testing of the ultra-quiet power regulation system for the sensor array in the BAT.

Video Credit: NASA