Tag: astronomy

Diversifying your research portfolio

9:53 am

In this paper [pdf] adapted from a lecture he gave at an astronomy conference, Harvard researcher Abraham Loeb warns young scientists that their tendency today to take on safe research projects is unwise. Moreover, he notes the increasing “herd mentality” due to “stronger social pressure”, “more competition in the job market,” and the “growing fraction of observational and theoretical projects . . . done in large groups with rigid research agendas and tight schedules.” Key quote:

It is always prudent to allocate some limited resources to innovative ideas beyond any dogmatic “mainstream,” because even if only one out of a million such ideas bears fruit, it could transform our view of reality and justify the entire effort. This lesson is surprisingly unpopular in the current culture of funding agencies like NSF or NASA, which promote research with predictable and safe goals.

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Hubble image of face-on galaxy

10:10 pm

Another spectacular Hubble Space Telescope image was released today, showing a face-on spiral galaxy in the Coma cluster, located about 320 million light years away. Key quote:

The galaxy, known as NGC 4911, contains rich lanes of dust and gas near its center. These are silhouetted against glowing newborn star clusters and iridescent pink clouds of hydrogen, the existence of which indicates ongoing star formation. Hubble has also captured the outer spiral arms of NGC 4911, along with thousands of other galaxies of varying sizes.

NGC 4911

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The Sun’s oxygen content does match the galaxy’s

9:47 am

A preprint paper [pdf] published today on the Los Alamos astro-ph website has found evidence that the oxygen and neon content of our Sun matches the abundances found in the galaxy. This result is important in that previous research has suggested that the Sun’s oxygen abundance was significantly higher than the rest of the galaxy, a possibility that not only caused problems for the theorists but raised interesting questions about the uniqueness of our solar system.

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A ground-based telescope matches the Hubble Space Telescope-NOT

6:01 am

Correction.Regular reader James Fincannon emailed me to say that he thinks the image below is an artist’s impression. He is correct. I should have looked more closely at the press release. In reading the actual research paper [pdf] on the results it seems that the VLT did some very sophisticated spectroscopy, thereby measuring the uneven distribution of the velocity and density of the gas around the star. The image below was then created, based largely on Hubble images combined with the new data. In other words, this ground-based telescope did not match the abilities of a space-based telescope in any way. Had the Hubble images not existed the astronomers would have struggled to interpret their spectroscopic data.

Some important astronomy news: The European Southern Observatory’s Very Large Telescope (VLT) has released this spectacular image of supernova 1987a, the first and so far only supernova visible to the naked eye since the invention of the telescope.

SN1987a

This image is important for two reasons. First, The data shows that the supernova explosion was not symmetrical, with more material being thrown outward in some directions than in others. This fact confirms what astronomers in recent years have increasingly come to believe: Supernovae explosions are not simple spherical bursts, but chaotic events ripping stars apart in a lopsided manner.

Second, this image demonstrates that ground-based telescopes are becoming amazingly good at doing what the Hubble Space Telescope has done routinely for the past two decades. Five years ago, no telescope on the ground could have resolved the inner ring of supernova 1987a. Only Hubble in space had that capability. Now, VLT can do it, almost as well as Hubble. Though a space-based telescope can still beat any ground-based telescope, it is great news that the technology for ground-based telescopes has improved so much, especially since there presently are no plans to replace Hubble.

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Kepler finds more than 100 Earthlike planets

12:51 pm

In its first six weeks of observation, the Kepler mission apparently found almost 150 planets similar in size to the Earth. The results, learned by accident because a talk given by one of the co-investigators was posted on the web, have not yet been officially announced because the project scientists feel a need for additional time to confirm them. Many of these so-called planets might turn out to be false positives, so some caution is in order.

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Swallowing a planet

9:39 am

A star with an appetite: Astronomers have used the Chandra X-Ray Observatory to take a closer look at an engimatic star in the constellation Pisces and found that the dust cloud that surrounds it as well as the unusual and enormous jets that shoot from it probably originated when the star evolved, expanded, and swallowed an orbiting companion, either a giant planet or companion star.

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very big stars

11:20 am

Using the Very Large Telescope in Chile, astronomers have identifed a number of stars with masses thought to range from 150 to as much as 300 times the mass of our Sun. Fun quote from the press release:

Within [star cluster] R136, only four stars weighed more than 150 solar masses at birth, yet they account for nearly half of the wind and radiation power of the entire cluster, comprising approximately 100 000 stars in total.

Stars this gigantic are believed to end their life in an explosion so intense it destroys the star entirely, leaving nothing behind but an expanding debris cloud, from which other stars and planets (and even life) can form.

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Metals in the inner galaxy

9:11 am

A preprint paper, published today on the astro-ph website but also accepted for publication in the journal Astronomy & Astrophysics, has confirmed what scientists have suspected about the dust and gas between the stars: As you travel closer to the center of the Milky Way galaxy this interstellar medium gets increasingly enriched with heavy elements. The scientists believe this is because the higher rate of supernovae in the inner galaxy sprays space with more of these atoms.

Since the field of extrasolar planets has also found that the more heavy elements a star contains, the more chance it will have planets, the new results above suggest that we will find more planets as we look inward towards the galactic center.

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Water found around carbon star; Bok globule

9:31 am

Water vapor detected in deep space, first near the carbon star V Cygni and second in two dark starless cores. The second detection is a first time water has been seen in these black clouds. Fun quote from the abstract of the first paper notes how the detection “raises the intriguing possibility that the observed water is produced by the vapourisation of orbiting comets or dwarf planets.”

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