This deep image of the area of sky around the elliptical galaxy NGC 5018 offers a spectacular view of its tenuous streams of stars and gas. These delicate features are hallmarks of galactic interactions, and provide vital clues to the structure and dynamics of early-type galaxies. [Higher-res image]A glittering host of galaxies populate this rich image taken with ESO’s VLT Survey Telescope, a state-of-the-art 2.6-m telescope designed for surveying the sky in visible light. The features of the multitude of galaxies strewn across the image allow astronomers to uncover the most delicate details of galactic structure.
Whereas ESO’s Very Large Telescope (VLT) can observe very faint astronomical objects in great detail, when astronomers want to understand how the huge variety of galaxies come into being they must turn to a different sort of telescope with a much bigger field of view. The VLT Survey Telescope (VST) is such a telescope. It was designed to explore vast swathes of the pristine Chilean night skies, offering astronomers detailed astronomical surveys of the southern hemisphere.
The powerful surveying properties of the VST led an international team of astronomers to conduct the VST Early-type GAlaxy Survey (VEGAS) [1] to examine a collection of elliptical galaxies in the southern hemisphere [2]. Using the sensitive OmegaCAM detector at the heart of the VST [3], a team led by Marilena Spavone from INAF-Astronomical Observatory of Capodimonte in Naples, Italy, captured images of a wide variety of such galaxies in different environments.
This wider-area image around the elliptical galaxy NGC 5018 offers a different perspective on the cosmic vastness. If seen with the unaided eye it will look almost empty. Here the extremely sensitive detectors of the VST have captured a myriad of stars, galaxies, and even a few errant asteroids crossing this area of the sky during the long exposures need to obtain the image. [Higher-res images]One of these galaxies is NGC 5018, the milky-white galaxy near the centre of this image. It lies in the constellation of Virgo (The Virgin) and may at first resemble nothing but a diffuse blob. But, on closer inspection, a tenuous stream of stars and gas — a tidal tail — can be seen stretching outwards from this elliptical galaxy. Delicate galactic features such as tidal tails and stellar streams are hallmarks of galactic interactions, and provide vital clues to the structure and dynamics of galaxies.
This annotated view of the surroundings of the elliptical galaxy NGC 5018 shows many of its neighbours. It also reveals a few asteroids that were captured by chance during the deep exposures needed to reveal the delicate streams of stars between the galaxies. [Higher-res images]As well as the many elliptical (and a few spiral) galaxies in this remarkable 400-megapixel image, a colourful variety of bright foreground stars in our own Milky Way Galaxy also pepper the image. These stellar interlopers, such as the vividly blue HD 114746 near the centre of the image, are not the intended subjects of this astronomical portrait, but happen to lie between the Earth and the distant galaxies under study. Less prominent, but no less fascinating, are the faint tracks left by asteroids in our own Solar System. Just below NGC 5018, the faint streak left by the asteroid 2001 TJ21 (110423) — captured over several successive observations — can be seen stretching across the image. Further to the right, another asteroid — 2000 WU69 (98603) — left its trace in this spectacular image.
While astronomers set out to investigate the delicate features of distant galaxies millions of light-years from Earth, in the process they also captured images of nearby stars hundreds of light-years away, and even the faint trails of asteroids only light-minutes away in our own Solar System. Even when studying the furthest reaches of the cosmos, the sensitivity of ESO telescopes and dark Chilean skies can offer entrancing observations much closer to home.
Notes
[1] VEGAS is a deep multi-band imaging survey of early-type galaxies carried out with the VLT Survey Telescope (VST), led by Enrichetta Iodice from INAF-Astronomical Observatory of Capodimonte in Naples, Italy.
[2] Elliptical galaxies are also known as early-type galaxies, not because of their age, but because they were once thought to evolve into the more familiar spiral galaxies, an idea now known to be false. Early-type galaxies are characterised by a smooth ellipsoidal shape and usually a lack of gas and active star formation. The bewildering diversity of shapes and types of galaxy is classified into the Hubble Sequence.
[3] OmegaCAM is an exquisitely sensitive detector formed of 32 individual charge coupled devices, and it creates images with 256 million pixels, 16 times greater than the ESA/NASA Hubble Space Telescope’s Advanced Camera for Surveys (ACS). OmegaCAM was designed and built by a consortium including institutes in the Netherlands, Germany and Italy with major contributions from ESO.
This chart shows most of the stars in the constellation Virgo (The Virgin) that can be seen with naked eye on a clear dark night. NGC 5018 can be found to the south of the brightest star in Virgo — α Virginis, better known by its popular name Spica. [Higher-res images]
On July 26th, 2018 VSS Unity completed its third rocket-powered test flight, a key step forward the path to space. Julia Hunter, Virgin Galactic Vice President and longtime employee, gives us a behind-the-scenes look into her life as a program leader, astrophysics scholar and space mom working to realize a longtime dream of opening commercial spaceflight to citizens and science. Join Julia as she narrates a key test flight that surpassed 170,800 feet, reaching Mach 2.47. VSS Unity was piloted by Dave Mackay and Mike “Sooch” Masucci, with pilots Kelly Latimer and Todd Ericson in carrier aircraft VMS Eve.
** SpaceX – Falcon 9 launches satellite for Indonesia and booster makes bulls-eye landing on sea platform:
1. Monday, August 6, 2018; 2-3:30 pm PDT (4-5:30 pm CDT, 5-6:30 pm EDT): We welcome Dr. Mackenzie Day, Assistant professor in Planetary Science at UCLA, will talk about Ghost Dunes on Mars.
2. Tuesday, August 7, 2018: 7-8:30 pm PDT; 9-10:30 pm CDT; 10-11:30 pm EDT: We welcome back Dr. Robert Zubrin on the upcoming Mars Society Conference (August 23-26, Pasadena, California) and more.
3. Wednesday, August August, 2018: Hotel Mars. See Upcoming Show Menu and the website newsletter for details. Hotel Mars is pre-recorded by John Batchelor. It is archived on The Space Show site after John posts it on his website.
4. Friday, August 10, 2018; 9:30 am -11 am PDT, (12:30 -2 pm EDT; 11:30 am -1 pm CDT): We welcome back Dr. Henry Hertzfeld do discuss space as a global commons and more. Our guest is the Director of the Space Policy Institute at GWU.
Peter Beck joins Jared in studio to talk about how Rocket Lab came to be. We dive in to what it took to start the company, challenges they have had, what Rocket Lab is setting out to do and a whole lot more.
Launches and other space news topics covered:
Launch Minute: Long March 3B Launches Beidou Satellites Long March 4B Launches Gaofen 11 Nexo II Copenhagen Launch
Space News: Rogue Planet Aurorae Astronauts Assigned to First Commercial Crew Missions Impact Rays Explained
Here is this week’s Space to Ground report from NASA on activities related to the International Space Station:
** Interviews with the astronauts who will fly on the first Boeing Starliner and SpaceX Dragon flights to the ISS (see yesterday’s event posting here):
** High school student compete to make the best breakfast for astronauts on the ISS:
Spatulas at the ready, teams of students from more than 30 high schools across the country faced off at Space Center Houston to find the best breakfast entrée to send to the crew on the International Space Station. Take a look at the action from the fourth annual High school students United with NASA to Create Hardware (HUNCH) Culinary Challenge, and the winning dish from Decatur High School in Decatur, Alabama. For more on the Culinary Challenge: http://hunchculinary.com/
** Hopefully, such breakfasts will make the Astronauts’ stomach flora happy:
Trillions of microorganisms live on and in the human body, many of them essential to its function and health. These organisms, collectively known as the microbiota, outnumber cells in the body by at least five times.
Microorganisms in the intestinal tract, the gut microbiota, play an especially important role in human health. An investigation on the International Space Station, Rodent Research-7 (RR-7), examines how the gut microbiota changes in response to spaceflight, and how that change in turn affects the immune system, metabolic system, and circadian or daily rhythms.
