Kuehnel: Created page with "Category:Accreting X-ray Pulsars Also known as: H 1553-542 [[http://simbad.u-strasbg.fr/simbad/sim-id?2S+1553-542] '''Monitoring data''': [http://xte.mit.edu/asmlc/srcs/..."

2018-04-18T14:38:33Z

Created page with "Category:Accreting X-ray Pulsars Also known as: H 1553-542 [[http://simbad.u-strasbg.fr/simbad/sim-id?2S+1553-542] '''Monitoring data''': [http://xte.mit.edu/asmlc/srcs/..."

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[[Category:Accreting X-ray Pulsars]]

Also known as: H 1553-542 [[http://simbad.u-strasbg.fr/simbad/sim-id?2S+1553-542]

'''Monitoring data''':
[http://xte.mit.edu/asmlc/srcs/x1553-542.html RXTE/ASM]
[http://swift.gsfc.nasa.gov/results/transients/weak/H1553-542/ Swift/BAT]
[http://maxi.riken.jp/top/index.php?cid=1&jname=J1557-544 MAXI]
[http://gammaray.msfc.nasa.gov/gbm/science/pulsars/lightcurves/2s1553.html Fermi/GBM pulsed flux]

= Coordinates =

{| class="wikitable"
| RA
| 15h 57m 49s
| Dec
| -54° 24' 54"
|-
| RA
| 239.454167
| Dec
| -54.415000
|-
| l
| 327.9441
| b
| -00.8570
|}
= Binary system =

== Orbit ==

{| class="wikitable"
! Parameter
! Value
! Unit
! Reference
|-
| Porb
| 29.56±0.53
| days
| <ref name="PahariPal12" />
|-
| Tperiastron
| 54488.38±0.51
| JD
| <ref name="PahariPal12" />
|-
| a sin i
| 168±18
| lt-sec
| <ref name="PahariPal12" />
|-
| e
| <0.09
|
| <ref name="Kelley83" />
|-
| ωperiastron
| ?
|
|
|-
| Mass function
| 5.3±1.2
| Msol
| <ref name="PahariPal12" />
|}
Alternative solution:

{| class="wikitable"
! Parameter
! Value
! Unit
! Reference
|-
| Porb
| 31.303(27)
| days
| <ref name="Tsygankov16" />
|-
| Tpi/2
| 2457 089.421(19)
| JD
| <ref name="Tsygankov16" />
|-
| a sin i
| 201.25(84)
| lt-sec
| <ref name="Tsygankov16" />
|-
| e
| 0.0351(22)
|
| <ref name="Tsygankov16" />
|-
| ωperiastron
| 163.4(35)
|
| <ref name="Tsygankov16" />
|}

Spin-down observed. Local spin-up during NuSTAR observations <ref name="Tsygankov16" />

== Optical Companion ==

Swift XRT found no optical counterpart down to 3-sigma limiting magnitudes 18.4 in V and fainter in other bands. [http://www.astronomerstelegram.org/?read=1371 ATel 1371]
= Available data from pointing instruments =

* '''RXTE''': Monitoring from 2008-Jan-06 to 2008-Mar-20
* '''Swift-XRT''': 4081 seconds on 2008 January 24
* '''NuSTAR''': 27 ks on 2015 April 3

= Description =

2S 1553-542 was discovered by SAS3 in June 1975 (Apparao et al. 1978). It is somewhat peculiar in having a low eccentricity in a wide orbit. After many years of quiescence, [http://www.astronomerstelegram.org/?read=1345 Krimm et al. (2007, ATel 1345)] observed another outburst, which was then monitored by RXTE/PCA [http://www.astronomerstelegram.org/?read=1373 (Pal & Pahari 2008, ATel 1373)].

After several more years of quiescence the source has been observed in outburst again in 2015.
Results from a NuSTAR observation, including a cyclotron line detection are reported by <ref name="Tsygankov16" />.

'''References'''

2S 1553-542 - Revision history

Kuehnel: Created page with "Category:Accreting X-ray Pulsars Also known as: H 1553-542 [[http://simbad.u-strasbg.fr/simbad/sim-id?2S+1553-542] '''Monitoring data''': [http://xte.mit.edu/asmlc/srcs/..."