Wednesday, May 2, 2007

Copernicus Ate Globular Clusters for Breakfast

Greetings Startrackers-- the latest news from the cosmos, via Baltimore, MD is that Mr. Hubble is giving us new insight into different ages of stars within Globular Clusters. At least that's what I gathered after my 8th time through the press release. As always, a picture is worth a thousand words, and in this case, a few million more stars. Thank the Gods Hubble is a machine. Copernicus would be hanged.




HUBBLE FINDS MULTIPLE STELLAR 'BABY BOOMS' IN A GLOBULAR CLUSTER

Astronomers have long thought that globular star clusters had a single "baby boom" of stars
early in their lives and then settled into a quiet existence.

New observations by NASA's Hubble Space Telescope, however, are showing that this idea
may be too simple. The Hubble analysis of the massive globular cluster NGC 2808
provides evidence that star birth went "boom, boom, boom," with three generations of
stars forming very early in the cluster's life.

"We had never imagined that anything like this could happen," said Giampaolo
Piotto of theUniversity of Padova in Italy and leader of the team that made the discovery.
"This is a complete shock."

Globular clusters are the homesteaders of our Milky Way Galaxy, born during our galaxy's
formation. They are compact swarms of typically hundreds of thousands of stars held
together by gravity.

"The standard picture of a globular cluster is that all of its stars formed at the same time, in
the same place, and from the same material, and they have co-evolved for billions of years,"
said team member Luigi Bedin of the European Space Agency, the European Organization for
Astronomical Research in the Southern Hemisphere (ESO), in Garching, Germany,
and the Space Telescope Science Institute in Baltimore, Md. "This is the cornerstone on which much of
the study of stellar populations has been built. So we were very surprised to find several distinct
populations of stars in NGC 2808. All of the stars were born within 200 million years very
early in the life of the 12.5-billion-year-old massive cluster."

Finding multiple stellar populations in a globular cluster so close to home has deep cosmological
implications, the researchers said.

"We need to do our best to solve the enigma of these multiple generations of stars found in these
Hubble observations so that we can understand how stars formed in distant galaxies in our early
universe," Piotto explained.

The astronomers used Hubble's Advanced Camera for Surveys to measure the brightness
and color of the cluster stars. Hubble's exquisite resolution allowed the
astronomers to sort out the different stellar populations. The Hubble measurements showed three
distinct populations, with each successive generation appearing slightly bluer. This
color difference suggests that successive generations contain a slightly different mix of some
chemical elements.

"One assumption, although we have no direct proof," said team member Ivan King of the
University of Washington in Seattle, "is that the successively bluer color of the stellar
populations indicates that the amount of helium increases with each generation of stars.
Perhaps massive star clusters like NGC 2808 hold onto enough gas to ignite a
rapid succession of stars."

The star birth would be driven by shock waves from supernovae and stellar winds from giant
stars, which compress the gas and make new stars, King explained. The gas would
be increasingly enriched in helium from previous generations of stars more massive than the Sun.

Astronomers commonly assume that globular clusters produce only one stellar generation,
because the energy radiating from the first batch of stars would clear out most of the
residual gas needed to make more stars. But a hefty cluster like NGC 2808, which
is two to three times more massive than a typical globular cluster, may have enough gravity to hang
onto that gas, which has been enriched by helium from the first stars. Of the about 150
known globular clusters in our Milky Way Galaxy, NGC 2808 is one of the most
massive, containing more than 1 million stars.

Friday, April 27, 2007

Happy Birthday Hubble










17 years ago, April 25, 1990, mankind made its giant leap. The one that Neil Armstrong promised. The shuttle birthed Hubble into orbit and the grand journey known as Hubble began. Each year at this time, NASA rewards us with a sensational picture and we eat it up the way hungry dogs ingest a treat. Hubble huggers unite. Details on the pic follow. Mahalo.


THE CARINA NEBULA: STAR BIRTH IN THE EXTREME


In celebration of the 17th anniversary of the launch and deployment of
NASA's Hubble Space Telescope, a team of astronomers is releasing one of
the largest panoramic images ever taken with Hubble's cameras. It is a
50-light-year-wide view of the central region of the Carina Nebula where
a maelstrom of star birth - and death - is taking place.


Hubble's view of the nebula shows star birth in a new level of detail.
The fantasy-like landscape of the nebula is sculpted by the action of
outflowing winds and scorching ultraviolet radiation from the monster
stars that inhabit this inferno. In the process, these stars are
shredding the surrounding material that is the last vestige of the giant
cloud from which the stars were born.


The immense nebula contains at least a dozen brilliant stars that are
roughly estimated to be at least 50 to 100 times the mass of our Sun.
The most unique and opulent inhabitant is the star Eta Carinae, at far
left. Eta Carinae is in the final stages of its brief and eruptive
lifespan, as evidenced by two billowing lobes of gas and dust that
presage its upcoming explosion as a titanic supernova.


The fireworks in the Carina region started three million years ago when
the nebula's first generation of newborn stars condensed and ignited in
the middle of a huge cloud of cold molecular hydrogen. Radiation from
these stars carved out an expanding bubble of hot gas. The island-like
clumps of dark clouds scattered across the nebula are nodules of dust
and gas that are resisting being eaten away by photoionization.


The hurricane blast of stellar winds and blistering ultraviolet
radiation within the cavity is now compressing the surrounding walls of
cold hydrogen. This is triggering a second stage of new star formation.


Our Sun and our solar system may have been born inside such a cosmic
crucible 4.6 billion years ago. In looking at the Carina Nebula we are
seeing the genesis of star making as it commonly occurs along the dense
spiral arms of a galaxy.


The immense nebula is an estimated 7,500 light-years away in the
southern constellation Carina the Keel (of the old southern
constellation Argo Navis, the ship of Jason and the Argonauts, from
Greek mythology).


This image is a mosaic of the Carina Nebula assembled from 48 frames
taken with Hubble Space Telescope's Advanced Camera for Surveys. The
Hubble images were taken in the light of neutral hydrogen. Color
information was added with data taken at the Cerro Tololo Inter-American
Observatory in Chile. Red corresponds to sulfur, green to hydrogen,
and blue to oxygen emission.


Credit for Hubble image: NASA, ESA, N. Smith (University of California,
Berkeley), and The Hubble Heritage Team (STScI/AURA)
Credit for CTIO image: N. Smith (University of California, Berkeley) and
NOAO/AURA/NSF


For images, videos, additional information about the Carina Nebula, and
Hubble 17th anniversary content visit:

http://hubblesite.org/news/2007/16

http://www.spacetelescope.org/news/html/heic0707.html

http://www.nasa.gov

Wednesday, April 25, 2007

Earth-like, sans-smog

OK Hubble Huggers, I'm back, feeling better about blogs than I ever have. Yeah, it's disposable information, but why not share stuff that's cool, right? RIGHT? Is anyone even listening? Forget what I said, blogs suck. But regardless, here's some great news from the universe, I'll be posting more releases as I get them. When you want information, make it primary source baby, all the way. Yours in the stars, David

Astronomers Find First Habitable Earth-like Planet



Astronomers have discovered the most Earth-like planet outside our
Solar System to date, an exoplanet with a radius only 50% larger than the Earth and possibly having liquid water on its surface. Using the ESO 3.6-m telescope, a team of Swiss, French and Portuguese scientists discovered a super-Earth about 5 times the mass of the
Earth that orbits a red dwarf, already known to harbour a Neptune-
mass planet. The astronomers have also strong evidence for the
presence of a third planet with a mass about 8 Earth masses.


This exoplanet - as astronomers call planets around a star other than
the Sun – is the smallest ever found up to now [1] and it completes
a full orbit in 13 days. It is 14 times closer to its star than the
Earth is from the Sun. However, given that its host star, the red
dwarf Gliese 581 [2], is smaller and colder than the Sun – and thus
less luminous – the planet nevertheless lies in the habitable zone,
the region around a star where water could be liquid!


“We have estimated that the mean temperature of this super-Earth
lies between 0 and 40 degrees Celsius, and water would thus be
liquid,” explains Stéphane Udry, from the Geneva Observatory
(Switzerland) and lead-author of the paper reporting the result.
“Moreover, its radius should be only 1.5 times the Earth’s radius,
and models predict that the planet should be either rocky – like our
Earth – or covered with oceans,” he adds.

This research is reported in a paper submitted as a Letter to the
Editor of Astronomy and Astrophysics (“The HARPS search for southern
extra-solar planets : XI. An habitable super-Earth (5 MEarth) in a 3-
planet system”, by S. Udry et al.)

The team is composed of Stéphane Udry, Michel Mayor, Christophe
Lovis, Francesco Pepe, and Didier Queloz (Geneva Observatory,
Switzerland), Xavier Bonfils (Lisbonne Observatory, Portugal), Xavier
Delfosse, Thierry Forveille, and C.Perrier (LAOG, Grenoble, France),
François Bouchy (Institut d'Astrophysique de Paris, France), and Jean-
Luc Bertaux (Service d'Aéronomie du CNRS, France)

Saturday, February 3, 2007

Hubble's Broken Camera

There's some confusion this week since Hubble's Advanced Camera for Surveys (ACS) stopped functioning. Maybe this blog will give me a platform for explaining it and tying it back to what it means to upgrade Hubble.

The ACS has had problems for the past year now and it looks like it's pretty much toast, but that does not mean that Hubble is toast and it's important to emphasize this. Science operations continue on Hubble using the other instruments on board. Hubble is an observatory, a veritable swiss-army-knife in space. The good people at STSCI (the group that governs the scientific use of Hubble) have switched their slate of scientific missions to a contingency plan that utilized the other, still-functioning instruments on Hubble.

What this means for servicing is still TBD. But it's clear the astronauts will have a pretty long checklist when they visit Hubble on SM4 (projected to launch September 2008). In addition to replacing batteries and gyros, installing 2 new instruments (widefield planetary camera 3 and cosmic origins spectrograph), I was under the impression they were going to try to fix STIS (currently dead weight on hubble) in orbit; could they fix ACS too? Is there room for all this equipment? Enough time?

I'm asking you-- you're the engineer, I'm just a man with a movie camera. Wait, you're not an engineer? I guess technically, I'm not even a man with a movie camera... just a bozo with a blog talking about stuff. Perhaps the original press release about the ACS malfunction can shed some light on this:


ENGINEERS INVESTIGATE ISSUE ON ONE OF HUBBLE'S SCIENCE INSTRUMENTS

GREENBELT, Md. - NASA engineers are examining a problem related to the
Advanced Camera for Surveys (ACS) aboard the agency's Hubble Space
Telescope.

On Jan. 27, the observatory entered a protective "safemode" condition
at 7:34 a.m. EST. An initial investigation indicates the camera has
stopped functioning, and the input power feed to its Side B
electronics package has failed.

The instrument had been operating on its redundant electronics since
June 30, 2006, when NASA engineers transitioned from the primary,
Side A, electronics package due to a malfunction. Engineers currently
are assessing the option to return ACS science operations to the
primary electronics so that observations could resume in a reduced
mode.

Hubble was recovered from safemode around 2 a.m. EST on Jan. 28, and
science observations will resume this week using the remaining Hubble
instruments: Wide Field Planetary Camera 2, Near Infrared Camera
Multi-Object Spectrograph, and the Fine Guidance Sensors.

In November 2006, the Space Telescope Science Institute in Baltimore
selected a set of backup non-ACS science programs for use in case of
a future ACS anomaly. These programs now will be inserted into the
science schedule to maintain a highly productive observing program.

An Anomaly Review Board was appointed on Jan. 29, to investigate the
ACS anomaly. The board will perform a thorough investigation and
assessment to decide the best course of action. The board is
scheduled to present their findings and recommendations by March 2.

"It is too early to know what influences the ACS anomaly may have on
Hubble Space Telescope Servicing Mission-4 planning" said Preston
Burch, associate director/program manager for the Hubble Space
Telescope. "It is important that the review board conduct a thorough
investigation that will allow us to determine if there are any
changes needed in the new instruments that will be installed on the
upcoming servicing mission so that we can be sure of maximizing the
telescope's scientific output. We are continuing to make excellent
progress in our preparations for the servicing mission, which is
presently targeted to fly in September 2008."

The Advanced Camera for Surveys is a third-generation instrument
consisting of three electronic cameras, filters and dispersers that
detect light from the ultraviolet to the near infrared. The
instrument was installed during a March 2002, servicing mission. It
was developed jointly by NASA's Goddard Space Flight Center,
Greenbelt, Md., Johns Hopkins University, Baltimore; Ball Aerospace,
Boulder, Colo.; and the Space Telescope Science Institute.

The Hubble Space Telescope is a project of international cooperation
between NASA and the European Space Agency. The Space Telescope
Science Institute conducts Hubble science operations. The Institute
is operated for NASA by the Association of Universities for Research
in Astronomy, Inc., Washington.

For information about the Hubble Space Telescope, visit:
http://www.nasa.gov/hubble

Monday, January 15, 2007

SAVING HUBBLE Blog Launch

Welcome to Saving Hubble's little home on the internet prairie. Well, that is if you don't count our other internet settlements at savinghubble.com and youtube. And our upcoming myspace site. Come to think of it, we've whored ourselves out pretty well on the 'net and the Saving Hubble team is getting better at it every day!

I once swore of blogs but I'm coming around. I have an unusual relationship with technology, unusual as compared with the average web-surfing bear, I suppose. Funny that for someone who has fallen madly in love with the Hubble Space Telescope, I show a more-than-occasional distrust of email, a wariness of cell phones, and a downright loathing of ipods. But I don't see these as paradoxes-- in fact, if Hubble is truly the nexus of great technology in both design and execution, shouldn't it be a standard by which all other technologies can be measured? Which are the devices through which we break new ground, transcend ourselves once more in the evolutionary chain? The airplane? The internet? The ipod nano? Hardly. And how about savinghubble.blogspot.com. Moving our film forward? Or just adding another layer to the pervasive milieu of white noise that already clouds your judgement?

Before Blogspot kicks us out of the party and you, dear reader, swear off the internet entirely as I've considered doing a few times while just writing this first blog entry, let me take the opportunity to officially welcome you to this running commentary, invite you to check out the other sites (mainly the homepage at www.savinghubble.com, complete with trailer and donation information), and encourage you to communicate with me and my Hubble-hugger associates as we look to start a dialogue about the film (which should be completed by Spring '07).

Orbitally Yours,
David