How to determine if a Debian upgrade updated the kernel

Let's say I have just done an aptitude safe-upgrade on a Debian system, but I was not paying attention so I did not notice if the kernel was updated or not.

How can I now determine if there was a kernel upgrade and a reboot is in order?

Compare the running kernel (uname -a) to the files in /boot and see if there is a newer version.

Aptitude logs to /var/log/aptitude and apt-get logs to /var/log/dpkg.log. If you've installed a new kernel the installation of the package should be recorded in one or both of those log files.

Check menuentry entries in your /boot/grub/grub.conf

check the time stamp of the kernel/vmlinuz* , grub.conf ... and see if it was recently updated.

Look at your /var/log/audit/audit.log and search for any file modifications in /boot

...I can go on and on ... -:)