Monday, July 13, 2015

Only a million miles to Pluto & Charon

True color image of Charon (left) and Plut (right), taken July 09 2015. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
In just over 21 hours, at 11:49:57 UTC on Tuesday 14th of July 2015, New Horizons will at it closet to Pluto. New Horizons is still roughly 1.1 million miles away from the point of closest approach but its moving at 13.8 kilometers per second with respect to Pluto (That is 14.5 km/s with respect to the Sun, or ~31,000 mph and 32,400 mph respectively).
Surface features on Pluto. July 12 2015. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

But already the views of Pluto and Charon are amazing, all the more so because they're just so different.
Surface features on Charon. July 12 2015. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
 For the latest from New Horizons, visit their JHU/APL webpage: http://pluto.jhuapl.edu/index.php

Thursday, July 09, 2015

Blobs in Space!

Interesting times, but not much time to comment on them.

The Sun is doing it's thing as always. Not much too special to talk about today. For more data go to http://sdo.gsfc.nasa.gov/data/

 AIA 211 Angstrom band is red, AIA 193 Angstrom band is green, and AIA 171 is blue


In our back yard the robotic missions to Minor Planets Ceres and Pluto are really getting interesting.

Dwarf planet Ceres as seen by NASA's DAWN mission
NASA's DAWN mission to Ceres is continuing its second mapping orbit. The CERES Image Of The Day website is worth looking at every now and again. The image on the right was taken on  Feb. 19, 2015 from a distance of nearly 29,000 miles (46,000 kilometers) from Ceres.

Fun Ceres facts: It is about 590 miles across, and accounts for about 25% of the entire asteroid belt's mass. Yet it is less than 1/14th of the mass of Plute, the other dwarf planet of note at the moment.

It is amazing to finally see non-deconvolved images of Pluto that actually look like something other than a blurry blob. [Read more at Space.com] Original images from JHU Applied Physics Lab.
New Horizon's image of Pluto and Charon taken on 06/29/2015 at a distance of 18 million km.

Sharpless 308. Copyright Kfir Simon
Bubbles. About 5,000 light years away from us is the beautiful Wolf-Rayet (stellar) bubble Sharpless 308. It is about 60 light years in diameter, and only 70,000 years old. The genetically modern human ancestors of ~98% or more of your DNA were present and still hanging out in Africa, but some were about to set off on extended holiday. [Credit: Kfir Simon, as seen on APOD]

Speaking of Wolf Rayet stars, how about Wolf Rayet galaxies? Why, it's a Hubble image of the famous SBS1415+437. (Just kidding, this galaxy is not well known, even among the so-called Wolf Rayet galaxies.)
The Wolf-Rayet galaxy SBS1415+437. Credit NASA/HST/Aloisi et al?

Go read the background at SpaceTelescope.org's Image of the Week. Although it is not clear from the Image of the Week site the image is probably that described in Aloisi et al, 2005, ApJ, 631, L45 which detected the presence of old (1+ Gyr) stars in SBS1415+437., which had bearing on an old (by now) debate about whether the so-called Wolf Rayet galaxies in the local Universe where young galaxies just experiencing their first burst of star formation (Answer: In general no, they're not).

I of course chose the bubble, superbubble, Wolf Rayet galaxy, and NGC 6503 images because I did some work on wind-blown bubbles, superbubbles, WR galaxies and NGC 6503 back in the days I was a professional astronomer. Red and green Solar images are for Micah and Caelan, who are very into that type of solar imagery at the moment.

Wednesday, January 14, 2015

Exciting times in NGC 4666

I missed this when it happened in December, but a new Type Ia supernova was discovered in the "nearby" starburst galaxy NGC 4666 by the  Automated Sky Survey for SuperNovae (ASAS-SN) project on December 9th. Bob King at Universe Today has a nice short article with a finding chart for NGC 4666, and some background information and images of the galaxy. A more recent, early January, amateur observation showing the supernova by Justin Ng can be found at EarthSky.org.

More on this topic some time later...

Tuesday, December 23, 2014

High Energy Astronomy News

Two items of note:

  1. Scientific American has a nice article on why the threat to life on Earth from Gamma Ray Bursts, in particular from the dying start Eta Carinae, is not something you need to worry about. (I've discussed putative GRB-caused events here and here).
  2. NuSTAR, an orbitting hard X-ry telescope, has captured some cool images of hard X-ray emission from the Sun (not a target NuSTAR was expected to look at, being designed for the study of Active Galactic Nuclei millions to billions of light years from Earth).
The NuSTAR data, seen in green and blue, reveal solar high-energy emission (green shows energies between 2 and 3 kiloelectron volts, and blue shows energies between 3 and 5 kiloelectron volts). The high-energy X-rays come from gas heated to above 3 million degrees. The red channel represents ultraviolet light captured by SDO at wavelengths of 171 angstroms, and shows the presence of lower-temperature material in the solar atmosphere at 1 million degrees. [Image and caption from NASA/JPL]