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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

610 results found.

  1. Trigger 555096: Swift detection of a possible burst
  2. Trigger 554491: Swift detection of a spike possibly from Sgr A*
  3. SGR 1806-20 outburst (trigger 549841), Swift-BAT refined analysis
  4. Trigger 549841: Swift detection of SGR1806-20
  5. Swift-BAT refined analysis of SGR 1E 1841-045 (Trigger=543763)
  6. Trigger 543763: SGR 1E 1841-045: Swift detection of a soft gamma repeater burst (aka Kes 73)
  7. GRB 121125A: Swift/UVOT Detection
  8. Swift-BAT refined analysis of the SGR 1806-20 outburst (trigger 535747)
  9. Trigger 535747: Swift detection of an outburst from SGR1806-20
  10. Fermi/GBM detection of an SGR-like burst
  11. Trigger 526660: Swift detection of 1 E 1841-045 (aka Kes 73)
  12. Swift starts a new program to find fainter transients
  13. Fermi/GBM detection of a burst from the magnetar 1E 2259+5
  14. Fermi GBM detection of an SGR-like burst
  15. Swift detection of an SGR burst from AXP 4U 0142+61
  16. Swift detection of short bursts from PSR J1647-4552
  17. SGR Swift J1834.9-0846: Correction to the Swift-BAT refined spectral analysis
  18. SGR Swift J1834.9-0846: Swift-BAT refined analysis of trigger 501752
  19. Swift detection of an SGR burst from Swift J1834.9-0846
  20. SGR 1834.9-0846/ GRB 110807A, I-band observations
  21. SGR 1834.9-0846/ GRB 110807A: archival IR observations
  22. SGR J1834.9-0846: A Neutron Star in W41?
  23. Swift SGR 1834.9-0846: Swift-BAT refined analysis
  24. Fermi GBM detection of a SGR-like burst
  25. GRB 110807A: Swift detection of a burst or a posible new SGR
  26. Swift detection of a SGR-like burst from the AXP 4U 0142+61
  27. Swift J1822.3-1606
  28. Swift J1822.3-1606: Swift-XRT detection of the X-ray counterpart
  29. Swift J1822.3-1606: A Probable New SGR in Ground Analysis of BAT Data
  30. SGR 1E 1841-045: early optical limit by "Pi of the Sky"
  31. SGR 1E 1841-045: Swift-BAT refined analysis
  32. SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
  33. SGR 1E 1841-045: Swift-BAT refined analysis
  34. SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
  35. GRB 110406A: Positional coincidence with NGC 404
  36. ICSP VLF observation of multiple SGR-like bursts from 1E 1841-045 on Feb. 9, 2011
  37. Fermi GBM detection of an SGR-like burst
  38. SGR-like outburst from the magnetar 1E 1841-04.5
  39. Fermi GBM detection of a burst from a galactic source
  40. Swift-BAT trigger 421695 is likely not astrophysical
  41. Swift-BAT refined analysis of trigger 421262
  42. An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
  43. Spin down rate and inferred dipole magnetic field of the new soft gamma-ray repeater SGR 1833-0832
  44. Fermi/GBM and Swift/BAT detection of a burst from SGR 1806-20
  45. SGR 1833-0832: Swift/UVOT Upper Limits
  46. SGR 1833-0832: Archival Chandra Observations
  47. SGR 1833-0832 is pulsed at 7.56 seconds
  48. SGR 1833-0832 is pulsed at 7.56 seconds
  49. Possible pulsation period in SGR 1833-0832
  50. Discovery of the Spin Period of SGR 1833-0832
  51. Probable SGR 1833-0832: Swift-XRT refined analysis
  52. Probable SGR 1833-0832: Enhanced Swift-XRT position
  53. Swift-XRT refined position of the probable new SGR 1833-0832
  54. Swift-BAT refined analysis of the probable new SGR 1833-0832
  55. GRB 100319A: Swift detection of a burst; possible SGR
  56. Swift Trigger #382159 is due to XTE J1752-223
  57. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  58. RXTE Discovery of Pulsations from SGR 0418+5729
  59. Konus-RF observation of SGR burst 090605A
  60. Discovery of a new soft gamma repeater source, SGR 0418+5729
  61. Refined analysis of ICSP VLF observation of SGR J1550-5418 bursts on 22nd January, 2009
  62. GRB 090417A: Early-type nature of the putative host
  63. GRB 090417A: nearby galaxy redshift
  64. SGR J1550-5418: two Fermi GBM triggers on March 22
  65. A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
  66. ATCA observation of SGR J1550-5418
  67. GRB 090303: Fermi GBM detection
  68. Konus-RF catches first GRB and SGR bursts
  69. SGR J1550-5418
  70. Ongoing activity of AXP/SGR 1E1547.0-5408
  71. SGR activity seen by BAT during ICSP Ionospheric Events
  72. Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
  73. Fermi Gamma-ray Burst Monitor trigger 255729682 is not a GRB
  74. ICSP VLF observation of the signatures of SGR/AXP 1E1547.0-5408 bursts
  75. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  76. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  77. AXP 1E1547.0-5408: RHESSI observations up to 400 keV
  78. Konus-Wind detection of very bright SGR-like burst on January 25, 2009
  79. Trigger 340734: Swift detection of a possible short burst
  80. AXP 1E1547.0-5408 activity with SGR bursts
  81. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  82. SGR 1806-20: Fermi GBM detection.
  83. SGR 1806-20: Fermi GBM detection
  84. SGR 0501+4516: optical observations in August
  85. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  86. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  87. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  88. Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
  89. GRB 081024: Swift detection of a burst
  90. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  91. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  92. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  93. Trigger 330353: Swift detection of a Galactic short soft burst
  94. SGR 0501+4516: preliminary results of the Suzaku ToO observation
  95. SGR 0501+4516 : P200 i-band observations
  96. SGR J0501+4516: radio pulsar searches with GBT and WSRT
  97. Recent VLA non-detection of SGR 0501+4516
  98. SGR 0501+4516: Spin Down Rate and Inferred Dipole Magnetic Field
  99. SGR 0501+4516: preliminary results of the first XMM-Newton observation
  100. nIR observations of SGR 0501+4516

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