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Mysterious Nova

Light Echoes around a Mysterious Nova

“In 1890 T Pyxidis had appeared, brightened, and disappeared. When I first came to Harvard they were still telling how it was found again during a routine survey of plates taken in 1919, and how Miss Leavitt exclaimed: ‘That star hasn’t been seen for almost thirty years!’ – the first … Continue Reading →

A Victorian Scandal

A Victorian Scandal

A recent event reminded me of a scandal of a sort that happened around 1850. At the center of it was John Russell Hind, a British astronomer (I mentioned him in a previous blog about archives). Hind was a superb observer who knew the sky very well. He discovered many … Continue Reading →

Post-Apocalyptic Musings

Post-apocalyptic Musings

Congratulations! You have survived the end of the world on December 21st, 2012. Many of you who never believed it may nevertheless be relieved, thinking that we can now forget about these apocalyptic prophecies. But, you would be wrong, in my opinion. It’s likely that, before too long, the Internet … Continue Reading →

What is a Galaxy

What is a Galaxy?

“Galaxy,” Defined — when I came across a paper with this title while browsing a recent issue of Astronomical Journal, I was intrigued. You would think that such a widely known term, one so fundamental to modern astronomy, would have been defined a long time ago. But then, sometimes the … Continue Reading →


A Midsummer Day’s Rant

This year, the summer solstice happens on Wednesday, June 20th, in mainland US, at 7:09 pm Eastern Daylight Time. This is often reported in the news as the beginning of the “official” or “astronomical” summer. Who decided that seasons begin at equinoxes and solstices, though? Words like “equinox” and “solstices” … Continue Reading →

An "X-ray Astronomer" Among Radio Telescopes

An “X-ray Astronomer” Among Radio Telescopes

To me, an observational astronomer, there is no such thing as X-ray astronomy. What I do is astronomical research on objects that happen to emit X-rays, as well as ultraviolet, visible, and infrared, etc. light. My research interest is not X-rays, but astronomical objects called cataclysmic variables and symbiotic stars … Continue Reading →

Archiving the Past for the Future

Archiving the Past for the Future

There is a group here at Goddard is called the HEASARC – High Energy Astrophysics Science Archive Research Center. This is where we keep data from old and new satellites. Even though every new satellite is an improvement over the last in one way or another, it is important to … Continue Reading →

Paying Tribute to the Scientists of the 16th & 17th Centuries

Paying Tribute to the Scientists of the 16th & 17th Centuries

We all know that Nicolaus Copernicus revolutionized our view of the universe. Who would you pick as the top scientists who further developed astronomy during the 16th and 17th centuries? I would pick Tycho Brahe, Johannes Kepler, Galileo Galilei, Isaac Newton, and Edmond Halley as my top five. I got … Continue Reading →

[Koji's blog] Astronomical Eye Candy

The HEASARC Picture of the Week for the week for Mar 21 is titled “The Ring.” Maggie posted the same image on Blueshift on Valentine’s Day, with a caption based on a Chandra press release. It sure is a pretty picture, combining Hubble and Chandra data, with a romantic connotation. … Continue Reading →

[Koji's blog] Even Spherical Cows Have Udders

In astrophysics, we often use the term “standard candle.” It is a highly useful, yet also very dangerous, term. The danger is that outsiders – the press, the general public, and even some scientists who are not intimately familiar with this particular subject – see this term and take it … Continue Reading →

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