HEASARC support for unencrypted FTP access will be ending on September 20, 2019. Please see this notice for details.
Welcome to ARK!
If you already have an ARK account, you must login first.
If you do not have an ARK account, select the group(s) you wish to join and
enter your e-mail address below.
The following ARK groups are open for anyone to join:
Your e-mail address:
Note: An address at which you can receive
e-mail from ARK is required. Our experience has shown that, if you provide an
e-mail address that is configured to forward to another e-mail address, it is
possible one of your mail servers may reject ARK's e-mail because of
DMARC. If that is the case,
you may need to deactivate your e-mail forwarding or provide a different
e-mail address when joining.
A service of the Astrophysics Science Division at NASA/GSFC and the High Energy Astrophysics Division of the Smithsonian Astrophysical Observatory (SAO)