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My Star Exploded Last Week

Posted By Alice On October 18, 2011 @ 11:19 am In AstroInfo Article | 2 Comments

My star¹ exploded² sometime in the week preceding last Monday³.

Let me repeat that because it is awesome.

MY STAR EXPLODED LAST WEEK!!!!!!!!!!!

¹My star: back in the summer of 2000 I had the fortune to be working as an undergraduate peon researcher in an astrophysics lab at MIT. In my seemingly endless hours sifting through data I found a previously-unidentified star (technically “source”) which we creatively named XTEJ1837+037. I have ever since referred to this as “my star” assuming it was such a pointless little dot that no one would care if I claimed the credit or not. It’s pretty close to Vega, and might be a binary system – a star orbiting a black hole or neutron star. It is perhaps more accurate to say “there was an explosion at my star.”

²Exploded: I’m being very loose with the definition of “exploded” here. NASA’s SWIFT Telescope [1] detected an outburst [2] near the coordinates of “my star.” This does not mean my star exploded, but something did something at that location. If it is a binary system then this outburst could easily be material from the regular star falling onto the black hole/neutron star companion.

³Sometime in the week preceding last Monday: SWIFT detected the burst between September 25, 2011 and October 15, 2011. Well, that means the light got to Earth two weeks ago – but as to when the burst actually happened? To know that we’d have to know how far away “my star” is.

Basic Stats

Source: an unidentified x-ray source, probably a binary system of a star and a neutron star and a black hole.

Name: XTEJ1837+037 or SWIFTJ1836.6+0341

Satellite used: first XTE, the X-Ray Timing Explorer, now SWIFT from NASA

What happened: a burst in the same area was detected using the burst-detecting instrument onboard SWIFT.

When: the detection occurred between September 25 and October 15, 2011.

Where in the sky: near Vega.

Where in the galaxy/universe: we don’t know. It could be in the galaxy, or it could be farther. It is probably in our galaxy, likely at least one kiloparsec away (far).

More Details and More Story

My Unidentified X-Ray Source

Source just means there’s a point in the sky that photons are coming from. The Sun is an identified and named source of visible light, radio waves, x-rays … etc. I was working under Ron Remillard at MIT at the time we found this source, and I was searching through data from the X-Ray Timing Explorer (XTE) to see if I could find gamma ray bursts for his research. I call it a star above because it was not an outburst like we were looking for, this object was steady – not something that shone brightly and then disappeared. The quickest and easiest name for that is “star.”  It is important to note that we were using an x-ray telescope to do this research. This star was not visible – it shone only in x-rays, and it was very dim which is why it had not been found before.

I still asked Ron what constellation it was in. To me, even though the star wasn’t visible, being able to look towards it or point towards it was important. I don’t think Ron understood why. I know it isn’t visible. I also know it is there. It’s by Vega, at right ascension 18 degrees 37 minutes and declination +37 degrees.

We even got to name it. Ron explained how this would work. We named it XTEJ 1837+037, there was no discussion or debate, the name is formulaic. XTE is the name of the satellite used. J is there to let you know what years the coordinates are good for. In this case the coordinates are good during epoch J (12:00 Universal Time on January 1, 2000). 1837+037 are the coordinates: right ascension and declination (which can be positive or negative).

It is still an “unidentified source” because we didn’t take the time to figure out what it was. It wasn’t what we were looking for. Dr. Hans Krimm who recently rediscovered it with SWIFT speculates that it is probably a binary system – a regular star orbiting a black hole or neutron star. That would explain the recent outburst.

An Outburst

As I said, we actually have no idea what happened yet, and I am no longer involved in this research. NASA’s SWIFT telescope detected an outburst in that same area. In Hans’s words – SWIFT detected an outburst only 1.3 arc minutes from “my star.”  That means it is very likely it is the same source.

With a binary system including a regular star and a black hole or neutron star, material can fall off the star and into the black hole or onto the neutron star. This is a catastrophic event, although not destructive to the binary system, and can easily create a large outburst. In fact, it is one of the types of supernovae. (Oops, I was confused. Type 1a supernovae are caused by mass falling from a star in a binary system onto a white dwarf not a neutron star or black hole. It can still create an outburst though.)

 

Stay tuned, I’ll be keeping up to date on this research. I hope you’re excited too!

Want More?

This is where it gets intense. The only links I have to point out to you are very, very technical. It took me three tries to read the first sentence of the first one … which could have something to do with how excited I was. Have fun deciphering!

The Astronomers Telegram [2] and the second one [3].

XTEJ1837+037 [4]

Here are some more tractable links about the spacecraft in question:

XTE [5]

SWIFT [4]

~ A l i c e !

 


Article printed from Alice's Astro Info: http://www.alicesastroinfo.com

URL to article: http://www.alicesastroinfo.com/2011/10/my-star-exploded-last-week/

URLs in this post:

[1] SWIFT Telescope: http://www.nasa.gov/mission_pages/swift/main/index.html

[2] detected an outburst: http://www.astronomerstelegram.org/?read=3684

[3] the second one: http://www.astronomerstelegram.org/?read=3687

[4] XTEJ1837+037: http://xte.mit.edu/asmlc/srcs/xtej1837+037.html

[5] XTE: http://xte.mit.edu/

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