






                       NED (NASA/IPAC Extragalactic Database)


            _A_d_d_r_e_s_s:
                 NED c/o IPAC
                 MS 100-22
                 California Institute of Technology
                 Pasadena CA 91125
                 USA

            _E_m_a_i_l: ned@ipac.caltech.edu

            _P_h_o_n_e: (818) 584-2903


            _D_e_s_c_r_i_p_t_i_o_n

            The NASA/IPAC Extragalactic Database  (NED)  is  an  ongoing
            project to organize a broad range of published extragalactic
            data into a computer-based central archive designed for fast
            and flexible query via electronic networks.

            The January 1991 version of NED provides  positions,  names,
            and basic data for 132,000 extragalactic objects, as well as
            related bibliographic references and notes from catalogs and
            other  publications.  It forwards to the user, upon request,
            files containing the data retrieved during  a  session.   It
            also  allows users to browse abstracts of recent articles of
            extragalactic interest from five major journals (_A &  _A,  _A_J
            _A_p_J,  _M_N_R_A_S,  _P_A_S_P,  their  Letters and Supplements), and to
            view  the  contents  of  several  major  catalogs.    Future
            releases  will  provide data from the current literature and
            from catalogs, and tools for searching the abstract database
            by content.

            NED is an object-oriented database, meaning that all  infor-
            mation  is  organized  around  a master list of astronomical
            objects (such as galaxies, groups of galaxies,  quasars  and
            radio  sources) obtained from detailed cross-identifications
            among some thirty major catalogs.  Additional  catalogs  are
            being  folded  in  continually.   Objects can be selected by
            name (a  high-level  name  interpreter  is  built  into  the
            _________________________
            The information in this section is provided  in  accor-
            dance  with the copyright notice appearing at the front
            of this guide.




            April 3, 1991               NNSC       Section 3.21,  Page 1








            interface), or by vicinity, either to a named object, or  to
            a position on the sky.

            _N_e_t_w_o_r_k _A_c_c_e_s_s

            You may access the NED service over Internet or  SPAN,  pro-
            vided you have a VT100 terminal or VT100 emulation software.

            On Internet, a connection to IPAC may be  set  up  with  the
            command: telnet ipac.caltech.edu

            From a node on SPAN, use the command:  set  host  IPAC  (The
            absolute SPAN address is 5.857.)

            Once you are connected to IPAC and  prompted  for  a  login,
            respond with: NED

            No password is needed.   From  this  point,  the  system  is
            self-documenting,  especially through the Help utilities and
            the control-h key sequence.  First-time users  may  want  to
            read  the  Tutorial  in  the  first  screen presented by the
            interface.

            _W_h_o _C_a_n _U_s_e _t_h_e _R_e_s_o_u_r_c_e/_R_e_s_t_r_i_c_t_i_o_n_s

            Available at no charge  to  the  international  astronomical
            community.

            _M_i_s_c_e_l_l_a_n_e_o_u_s _I_n_f_o_r_m_a_t_i_o_n

            This work is carried out by the Jet  Propulsion  Laboratory,
            California  Institute of Technology, under contract with the
            National Aeronautics and Space Administration  (Astrophysics
            Division, Science Operations Branch).

                 George Helou (818) 584-2928
                 Barry Madore (818) 584-2912
                 Marion Schmitz (818) 584-2994
                 Harold Corwin (818) 584-2937












            April 3, 1991               NNSC       Section 3.21,  Page 2


