APOD: The Cloudy Cores of Active Galaxies (2014 Feb 24)

[DavidLeodis]

On clicking on the 'X-ray Timing Explorer' link in the explanation to the APOD I get a security alert in which it states "The security certificate presented by this website was not issued by a trusted certificate authority. Security certificate problems may indicate an attempt to fool you or intercept any data you send to the server. We recommend that you close this webpage and do not continue to this website.". However, when I click on the same link in the explanation with this discussion about the APOD I bring up the website! I wonder if anyone else has/had this problem?

[Chris Peterson]

On clicking on the 'X-ray Timing Explorer' link in the explanation to the APOD I get a security alert in which it states "The security certificate presented by this website was not issued by a trusted certificate authority. Security certificate problems may indicate an attempt to fool you or intercept any data you send to the server. We recommend that you close this webpage and do not continue to this website.". However, when I click on the same link in the explanation with this discussion about the APOD I bring up the website! I wonder if anyone else has/had this problem? :?

I think it's a configuration problem with your computer. On my machine, using Firefox, I get no such error, and I can view the certificate and see the issuer (Entrust, Inc). The certificate is in force and unexpired. Maybe you haven't updated your software lately? Certificate authority updates are normally a part of every Windows update. Not sure how Macs handle this.

In any case, the site is perfectly safe to visit. You can add an exception.

[geckzilla]

Alternatively, just do not use https. No question about how insecure http is! http://heasarc.gsfc.nasa.gov/docs/xte/XTE.html

[Chris Peterson]

Alternatively, just do not use https. No question about how insecure http is! http://heasarc.gsfc.nasa.gov/docs/xte/XTE.html

It's unclear why the original link is to the secure version of the page. Hardly seems necessary in this case.

[DavidLeodis]

Thanks Chris and geckzilla for your very prompt responses.

My security is up to date. Incidentally I've found that if I use the link with the APOD after I've used it in the discussion link then it brings up the website, but if I then delete my browsing history I again get the security warning when I try the APOD link. Strange! I use IE 10 and Norton.

I've just used Firefox and that worked OK.

[DavidLeodis]

The "recently been found" link brings up an abstract of 'First X-ray-Based Statistical Tests for Clumpy-Torus Models: Eclipse Events from 230 Years of Monitoring of Seyfert AGN'. As nobody else seems to have mentioned it I assume it is only me that was stunned by the 230 years!

[Chris Peterson]

The "recently been found" link brings up an abstract of 'First X-ray-Based Statistical Tests for Clumpy-Torus Models: Eclipse Events from 230 Years of Monitoring of Seyfert AGN'. As nobody else seems to have mentioned it I assume it is only me that was stunned by the 230 years! :shock:

They mean they've collected 230 years worth of data- several years each for 55 objects. Just like you can complete a hundred man-year project in one year if you have 100 men. Since it's a statistical analysis, the total amount of data is significant, not the absolute interval over which it was collected (which is just a few years).