Supermassive black hole at the center of our galaxy

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fred8615
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Joined: October 12th, 2009, 12:29 pm
Location: Sorrento, LA

Supermassive black hole at the center of our galaxy

Post by fred8615 »

Supermassive black hole at the center of our galaxy gives up a secret

http://news.cnet.com/2300-11386_3-10011 ... ?tag=mncol

Got some nice pics too.
Frederick J. Barnett
"Someone's got to take the responsibility if the job's going to get done!! Do you think that's easy?!" Gregory Peck - The Guns Of Navarone
Christopher K.
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Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Supermassive black hole at the center of our galaxy

Post by Christopher K. »

Sagittarius A* is the site of an intense radio emission, some 26,000 light-years away in the core of our Milky Way (which, from Earth's vantage point, lies in Sagittarius the Archer). At least two dozen stars are known to be in the grip of this probable supermassive black hole. In 2000 one star passed only ten light-years from the object; another has an elliptical orbit which it completes in less than sixteen years.

The center of the Milky Way lies three-and-a-quarter degrees NNE of the Butterfly Cluster (M6), four degrees east of Theta Ophuichi, and one-and-a-quarter degrees SSW of 3 Sagittarii. For what it's worth, here are selected times during which this area is highest in the Baton Rouge sky...
4 May = 4am
12 May = 3:30am
19 May = 3am
27 May = 2:30am
4 June = 2am
11 June = 1:30am
19 June = 1am
26 June = 12:30am
4 July = 12am
11 July = 11:30pm
18 July = 11pm
26 July = 10:30pm
3 August = 10pm
10 August = 9:30pm
18 August = 9pm
26 August = 8:30pm
2 September = 8pm

Notice the center of the Milky Way Galaxy is highest at midnight on the Fourth of July; I think that's cool. Sagittarius A* came in at #49 in Bob Berman's 50 Weirdest Objects in the Cosmos.

More information:
http://www.daviddarling.info/encycloped ... ius_A.html
http://www.nasa.gov/mission_pages/chand ... /saga.html
Celestial Handbook by Robert Burnham, pp. 1635-1644 (about the Galactic Center in general)
Christopher K.
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Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Supermassive black hole at the center of our galaxy

Post by Christopher K. »

A brief note by David Eicher in the March Astronomy mentions "[The] Hubble [Space Telescope] showed us that nearly every galaxy seems to have a supermassive black hole at its center". Before that, the black hole idea was mostly a hypothesis and had been ever since John Michell suggested them in 1783.

More information:
March 2013 Astronomy, p. 9.
Christopher K.
Posts: 5803
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Supermassive black hole at the center of our galaxy

Post by Christopher K. »

Monday's APOD is actually a five-second film showing (with the data we have now) the vantage point of an observer on a spaceship orbiting a black hole. Tuesday's APOD takes it "one step further".

1 July APOD:
http://apod.nasa.gov/apod/ap130701.html

2 July APOD:
http://apod.nasa.gov/apod/ap130702.html
Christopher K.
Posts: 5803
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Supermassive black hole at the center of our galaxy

Post by Christopher K. »

Another brief note from Mr. Eicher. The ALMA has detected possible evidence of star formation within two light-years of our galaxy's central black hole. ALMA is the Atacama Large Millimeter/Submillimeter Array telescope in Chile. Farhad Yusef-Zadeh of Northwestern University and his colleagues have found silicon monoxide, some of it leaving that area at velocities reaching up to 200 kilometers per second. Silicon monoxide is common in molecular clouds; when it is excited during the creation of stars it emits very specific wavelengths of microwave radiation.

Note at:
Astronomy, August 2013, p. 9

More information at:
http://www.almaobservatory.org/en/press ... black-hole
http://www.astronomy.com/~/link.aspx?_i ... 52ad652fdb
Christopher K.
Posts: 5803
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Supermassive black hole at the center of our galaxy

Post by Christopher K. »

The 18 January APOD shows the center of the Milky Way in infrared light (courtesy Hubble and Spitzer). The NICMOS actually worked on this composite image in 2008.

The NICMOS:
http://www.stsci.edu/instruments/nicmos/

18 January APOD:
http://apod.nasa.gov/apod/ap150118.html
Christopher K.
Posts: 5803
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Supermassive black hole at the center of our galaxy

Post by Christopher K. »

Tonight at 7:30pm, BRAS member (and most recent winner of the Conrad Volunteer of the Year Award) Peter Lazar will present "Black Holes: The One-Way Trip" at the Highland Road Park Observatory. Admission is free and the lecture is aimed at a general adult audience.
Christopher K.
Posts: 5803
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Supermassive black hole at the center of our galaxy

Post by Christopher K. »

The ALMA will hopefully shake off the virus shutdowns to come back online before the end 2021...
https://www.almaobservatory.org/en/anno ... s-in-2021/

Cycle 7 of planned observations should resume in March, with Cycle 8 beginning in October.
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