SpaceX Launches Iridium 8 – Replay

The launch replay.

Below is the replay of the first-stage landing on the barge:

This launch of 10 Iridium NEXT satellites from Space Launch Complex 4E (SLC-4E) at Vandenberg Air Force Base in California, is the eighth and final set of satellites in a series of 75 that SpaceX will launch for Iridium’s next generation global satellite constellation.

Weather looks good – good luck SpaceX

The COW and What?

“Over three days, the Cow produced a sudden explosion of light at least 10 times brighter than a typical supernova, and then it faded over the next few months. This unusual event occurred inside or near a star-forming galaxy known as CGCG 137-068, located about 200 million light-years away in the constellation Hercules. The Cow was first observed by the NASA-funded Asteroid Terrestrial-impact Last Alert System telescope in Hawaii.

So exactly what is the Cow? Using data from multiple NASA missions, including the Neil Gehrels Swift Observatory and the Nuclear Spectroscopic Telescope Array (NuSTAR), two groups are publishing papers that provide possible explanations for the Cow’s origins. One paper argues that the Cow is a monster black hole shredding a passing star. The second paper hypothesizes that it is a supernova — a stellar explosion — that gave birth to a black hole or a neutron star.

‘We’ve never seen anything exactly like the Cow, which is very exciting,” said Amy Lien, an assistant research scientist at the University of Maryland, Baltimore County and NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We think a tidal disruption created the quick, really unusual burst of light at the beginning of the event and best explains Swift’s multiwavelength observations as it faded over the next few months.’ ” — NASA

And in an unrelated bit: did you hear about the mysterious radio signals picked up by the CHIME radio telescope? What is causing the fast radio bursts is unknown, there is even speculation that these are intentional pulses i.e. from aliens. I don’t think I’d go that far, but just what is causing them is a mystery nonetheless. A pretty good explanation can be found at Scientific American.

Perhaps we will see a lot more of them as times goes on with the CHIME radio telescope.

Herbig-Haro Objects

Hubble took a look at a star formation area with what is a baby star just born (in astronomical time scales). One of the effects in the area are these Herbig-Haro objects.

Image: SA/Hubble & NASA, K. Stapelfeldt; CC BY 4.0

ESA: In this image the NASA/ESA Hubble Space Telescope has captured the smoking gun of a newborn star, the Herbig–Haro objects numbered 7 to 11 (HH 7–11). These five objects, visible in blue in the top centre of the image, lie within NGC 1333, a reflection nebula full of gas and dust found about a thousand light-years away from Earth.

Herbig-Haro objects like HH 7–11 are transient phenomena. Travelling away from the star that created them, at a speed of up to 250 000 kilometres per hour they disappear into nothingness within a few tens of thousands of years. The young star that is the source of HH 7-11 is called SVS 13 and all five objects are moving away from SVS 13 toward the upper left. The current distance between HH 7 and SVS 13 is about 20 000 times the distance between Earth and the Sun.

Herbig–Haro objects are formed when jets of ionised gas ejected by a young star collide with nearby clouds of gas and dust at high speeds. The Herbig-Haro objects visible in this image are no exception to this and were formed when the jets from the newborn star SVS 13 collided with the surrounding clouds. These collisions created the five brilliant clumps of light within the reflection nebula.

OSIRIS-REx Sees Home

The NAVCAM aboard the OSIRIS=REx spacecraft took this image on 19 December 2018 and it is looking at Aseroid Bennu and the Earth and Moon. Can you spot them? Click the image for a much larger version and that might help. You can get the full image here – and it’s not so large that even a slow connection will take a long time.

There is also part of a constellation in the lower right, take a guess at that too before reading the caption which is below the fold. I am pleased to say I got it, but only because of dumb-luck, still. . .

Thanks to: NASA, Goddard, University of Arizona, and Lockheed Martin Space for the image.
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Hubble and a Cepheid Variable Star

The last Hubble post showed a variable star known as a RR Lyrae, this is another type of variable star called a Cepheid variable.

Keep in mind this particular image was a holiday offering by Hubble when reading the original caption below.

While we will go more into variable stars in the very near future, you can get a brief description of them here.

NASA/Hubble:  This festive NASA Hubble Space Telescope image resembles a holiday wreath made of sparkling lights. The bright southern hemisphere star RS Puppis, at the center of the image, is swaddled in a gossamer cocoon of reflective dust illuminated by the glittering star. The super star is ten times more massive than the Sun and 200 times larger.

RS Puppis rhythmically brightens and dims over a six-week cycle. It is one of the most luminous in the class of so-called Cepheid variable stars. Its average intrinsic brightness is 15,000 times greater than the Sun’s luminosity.

The nebula flickers in brightness as pulses of light from the Cepheid propagate outwards. Hubble took a series of photos of light flashes rippling across the nebula in a phenomenon known as a “light echo.” Even though light travels through space fast enough to span the gap between Earth and the Moon in a little over a second, the nebula is so large that reflected light can actually be photographed traversing the nebula.

By observing the fluctuation of light in RS Puppis itself, as well as recording the faint reflections of light pulses moving across the nebula, astronomers are able to measure these light echoes and pin down a very accurate distance. The distance to RS Puppis has been narrowed down to 6,500 light-years (with a margin of error of only one percent).

Image credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA) – Hubble/Europe Collaboration; Acknowledgement: H. Bond (STScI and Pennsylvania State University)

Text credit: Space Telescope Science Institute (STScI)

NGC 1466 and the Cosmic Distance Scale

Image: ESA / Hubble / NASA

ESA: This image from the NASA/ESA Hubble Space Telescope reveals an ancient, glimmering ball of stars called NGC 1466. It is a globular cluster — a gathering of stars all held together by gravity — that is slowly moving through space on the outskirts of the Large Magellanic Cloud, one of our closest galactic neighbours.

NGC 1466 certainly is one for extremes. It has a mass equivalent to roughly 140 000 Suns and an age of around 13.1 billion years, making it almost as old as the Universe itself. This fossil-like relic from the early Universe lies some 160 000 light-years away from us.

Nestled within this ancient time capsule are 49 known RR Lyrae variable stars, which are indispensable tools for measuring distances in the Universe. These variable stars have well-defined luminosities, meaning that astronomers know the total amount of energy they emit. By comparing this known luminosity to how bright the stars appear in the sky, their distance can be easily calculated. Astronomical objects such as this are known as standard candles, and are fundamental to the so-called cosmic distance ladder.

Image From the Far Side

Congratulations to China and the Chinese space program. They made history by putting the Chang’e4 lander on the surface of the Moon, on the far side – the first time in history.

The lander which includes a rover will study mineral composition and reportedly do low frequency radio-astronomy landed in Von Karman crater.

The crater you see in the image above is not Von Karman, it is a small crater within Von Karman. Von Karman is a very large crater 180 Km / 106 miles across and is located in he south-eastern quadrant on the far-side of the moon and thus never visible to us (Longitude: 176.245 east / Latitude: 44.451 south). From the photo it appears the part of the crater wall might be visible in the background.

Here is a view from the Virtual Moon Atlas. I checked and there is no information on the smaller caters within the main crater. So I was unable to figure out exactly where it is from the image.  If you don’t have the Virtual Moon Atlas you can download it here. it is free and a great program.

The upper image is from China Xinhua News and by the way, if you are wondering how they got the signal back to Earth, it was done by a relay from the Queqiao relay satellite operating in orbit around the second Lagrangian (L2) point of the earth-moon system.

The lower image as noted is from the Virtual Moon Atlas and you can (or should be able to) get larger versions by clicking the images.