12
1 Introduction to the Pulsars
Table 1.1 The names and their initials of observatories early discovering pulsars
Number
Name of observatory
Identifier with initial
letter
Notes
1
Cambridge Observatory,
UK
CP
CP 1919
2
Harvard College
Observatory, USA
HP
3
National Radio Astronomy
Observatory, USA
NP
NP 0531
4
Arecibo Observatory, USA
AP
Managed by
Cornell
University
5
Jodrell Bank Observatory,
UK
JP
6
Molonglo Observatory
Synthesis Telescope
(MOST), Australia
MP
Operated by
the University
of Sydney
of 25 calendar years was used as an epoch in most of the stellar catalogues, and
expressed as the capital letter “B”, such as epoch B1900.0, B1925.0, B1950.0 and
so on. Consequently, the naming rule was revised to be “PSR Brrrrsdddd”, where
“rrrr” denotes four digits of the right ascension, in which the first two digits are still
expressed with hours and the last two digits with minutes; “s” denotes the positive sign
“+” or the negative one “−”; “dddd” denotes four digits of the declination, in which
the first two digits are expressed with degrees, the third and fourth digits are extended
respectively to 0.1 ° and 0.01 °. In some cases, the declination is denoted only by
the first two digits. Supposed that the right ascensions of two pulsars are 19h13min,
while their declinations are respectively 16º02
and 16º40
, the former is named PSR
B1913+16, and the latter is named PSR B1913+167 due to its declination conversed
into 16.7 °. Sometimes, the reference epoch B1950.0 is regarded as a default, and the
letter “B” is also neglected in the past some references. And thus, the names of the two
pulsars are respectively written into PSR 1913+16 and PSR 1913+167. Furthermore,
the discrepancies of the pulsar’s angular positions in some globular clusters are so
small that they can not be distinguished distinctly. And thereby a capital litter is
usually appended behind the declination digits to distinguish the different positions,
such as PSR 0021–72C, PSR 0021–72D and so on.
At present, according to the International Astronomical Union (IAU) regulation,
the naming rule of pulsars is the standard epoch J2000.0 has been used uniformly in
stellar catalogues since 1984; the declinations are denoted by four digits, in which the
first two digits are still expressed with angular degrees and the latter two digits with
arc-minutes rather than 0.1 ° or 0.01 °. For the pulsars discovered before 1993, two
coordinate systems B1950.0 and J2000.0 may be used, and distinguished respectively
1 Introduction to the Pulsars
Table 1.1 The names and their initials of observatories early discovering pulsars
Number
Name of observatory
Identifier with initial
letter
Notes
1
Cambridge Observatory,
UK
CP
CP 1919
2
Harvard College
Observatory, USA
HP
3
National Radio Astronomy
Observatory, USA
NP
NP 0531
4
Arecibo Observatory, USA
AP
Managed by
Cornell
University
5
Jodrell Bank Observatory,
UK
JP
6
Molonglo Observatory
Synthesis Telescope
(MOST), Australia
MP
Operated by
the University
of Sydney
of 25 calendar years was used as an epoch in most of the stellar catalogues, and
expressed as the capital letter “B”, such as epoch B1900.0, B1925.0, B1950.0 and
so on. Consequently, the naming rule was revised to be “PSR Brrrrsdddd”, where
“rrrr” denotes four digits of the right ascension, in which the first two digits are still
expressed with hours and the last two digits with minutes; “s” denotes the positive sign
“+” or the negative one “−”; “dddd” denotes four digits of the declination, in which
the first two digits are expressed with degrees, the third and fourth digits are extended
respectively to 0.1 ° and 0.01 °. In some cases, the declination is denoted only by
the first two digits. Supposed that the right ascensions of two pulsars are 19h13min,
while their declinations are respectively 16º02
and 16º40
, the former is named PSR
B1913+16, and the latter is named PSR B1913+167 due to its declination conversed
into 16.7 °. Sometimes, the reference epoch B1950.0 is regarded as a default, and the
letter “B” is also neglected in the past some references. And thus, the names of the two
pulsars are respectively written into PSR 1913+16 and PSR 1913+167. Furthermore,
the discrepancies of the pulsar’s angular positions in some globular clusters are so
small that they can not be distinguished distinctly. And thereby a capital litter is
usually appended behind the declination digits to distinguish the different positions,
such as PSR 0021–72C, PSR 0021–72D and so on.
At present, according to the International Astronomical Union (IAU) regulation,
the naming rule of pulsars is the standard epoch J2000.0 has been used uniformly in
stellar catalogues since 1984; the declinations are denoted by four digits, in which the
first two digits are still expressed with angular degrees and the latter two digits with
arc-minutes rather than 0.1 ° or 0.01 °. For the pulsars discovered before 1993, two
coordinate systems B1950.0 and J2000.0 may be used, and distinguished respectively