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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.

Lucene Examples (click to copy):

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

600 results found.

  1. Trigger 535747: Swift detection of an outburst from SGR1806-20
  2. Fermi/GBM detection of an SGR-like burst
  3. Trigger 526660: Swift detection of 1 E 1841-045 (aka Kes 73)
  4. Swift starts a new program to find fainter transients
  5. Fermi/GBM detection of a burst from the magnetar 1E 2259+5
  6. Fermi GBM detection of an SGR-like burst
  7. Swift detection of an SGR burst from AXP 4U 0142+61
  8. GRB 110921A: Enhanced Swift-XRT position
  9. Swift detection of short bursts from PSR J1647-4552
  10. SGR Swift J1834.9-0846: Correction to the Swift-BAT refined spectral analysis
  11. SGR Swift J1834.9-0846: Swift-BAT refined analysis of trigger 501752
  12. Swift detection of an SGR burst from Swift J1834.9-0846
  13. SGR 1834.9-0846/ GRB 110807A, I-band observations
  14. SGR 1834.9-0846/ GRB 110807A: archival IR observations
  15. SGR J1834.9-0846: A Neutron Star in W41?
  16. Swift SGR 1834.9-0846: Swift-BAT refined analysis
  17. Fermi GBM detection of a SGR-like burst
  18. GRB 110807A: Swift detection of a burst or a posible new SGR
  19. Swift detection of a SGR-like burst from the AXP 4U 0142+61
  20. Swift J1822.3-1606
  21. Swift J1822.3-1606: Swift-XRT detection of the X-ray counterpart
  22. Swift J1822.3-1606: A Probable New SGR in Ground Analysis of BAT Data
  23. SGR 1E 1841-045: early optical limit by "Pi of the Sky"
  24. SGR 1E 1841-045: Swift-BAT refined analysis
  25. SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
  26. SGR 1E 1841-045: Swift-BAT refined analysis
  27. SGR 1E 1841-045: Swift detection of a soft gamma repeater burst
  28. GRB 110406A: Positional coincidence with NGC 404
  29. ICSP VLF observation of multiple SGR-like bursts from 1E 1841-045 on Feb. 9, 2011
  30. Fermi GBM detection of an SGR-like burst
  31. SGR-like outburst from the magnetar 1E 1841-04.5
  32. Fermi GBM detection of a burst from a galactic source
  33. Swift-BAT trigger 421695 is likely not astrophysical
  34. Swift-BAT refined analysis of trigger 421262
  35. An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
  36. Spin down rate and inferred dipole magnetic field of the new soft gamma-ray repeater SGR 1833-0832
  37. Fermi/GBM and Swift/BAT detection of a burst from SGR 1806-20
  38. SGR 1833-0832: Swift/UVOT Upper Limits
  39. SGR 1833-0832: Archival Chandra Observations
  40. SGR 1833-0832 is pulsed at 7.56 seconds
  41. SGR 1833-0832 is pulsed at 7.56 seconds
  42. Possible pulsation period in SGR 1833-0832
  43. Discovery of the Spin Period of SGR 1833-0832
  44. Probable SGR 1833-0832: Swift-XRT refined analysis
  45. Probable SGR 1833-0832: Enhanced Swift-XRT position
  46. Swift-XRT refined position of the probable new SGR 1833-0832
  47. Swift-BAT refined analysis of the probable new SGR 1833-0832
  48. GRB 100319A: Swift detection of a burst; possible SGR
  49. Swift Trigger #382159 is due to XTE J1752-223
  50. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  51. RXTE Discovery of Pulsations from SGR 0418+5729
  52. Konus-RF observation of SGR burst 090605A
  53. Discovery of a new soft gamma repeater source, SGR 0418+5729
  54. Refined analysis of ICSP VLF observation of SGR J1550-5418 bursts on 22nd January, 2009
  55. GRB 090417A: Early-type nature of the putative host
  56. GRB 090417A: nearby galaxy redshift
  57. SGR J1550-5418: two Fermi GBM triggers on March 22
  58. A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
  59. ATCA observation of SGR J1550-5418
  60. GRB 090303: Fermi GBM detection
  61. Konus-RF catches first GRB and SGR bursts
  62. SGR J1550-5418
  63. Ongoing activity of AXP/SGR 1E1547.0-5408
  64. SGR activity seen by BAT during ICSP Ionospheric Events
  65. Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
  66. Fermi Gamma-ray Burst Monitor trigger 255729682 is not a GRB
  67. ICSP VLF observation of the signatures of SGR/AXP 1E1547.0-5408 bursts
  68. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  69. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  70. AXP 1E1547.0-5408: RHESSI observations up to 400 keV
  71. Konus-Wind detection of very bright SGR-like burst on January 25, 2009
  72. Trigger 340734: Swift detection of a possible short burst
  73. AXP 1E1547.0-5408 activity with SGR bursts
  74. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  75. SGR 1806-20: Fermi GBM detection.
  76. SGR 1806-20: Fermi GBM detection
  77. SGR 0501+4516: optical observations in August
  78. GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
  79. SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
  80. SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
  81. Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
  82. GRB 081024: Swift detection of a burst
  83. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  84. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  85. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  86. Trigger 330353: Swift detection of a Galactic short soft burst
  87. SGR 0501+4516: preliminary results of the Suzaku ToO observation
  88. SGR 0501+4516 : P200 i-band observations
  89. SGR J0501+4516: radio pulsar searches with GBT and WSRT
  90. Recent VLA non-detection of SGR 0501+4516
  91. SGR 0501+4516: Spin Down Rate and Inferred Dipole Magnetic Field
  92. SGR 0501+4516: preliminary results of the first XMM-Newton observation
  93. nIR observations of SGR 0501+4516
  94. INTEGRAL ToO observation of SGR0501+4516
  95. SGR 0501+4516: Confirmation of the NIR counterpart
  96. SGR 0501+4516: Detection of possible optical counterpart
  97. SGR 0501+4516: WHT observations of the possible near-infrared counterpart
  98. VLA non-detection of SGR 0501+4516
  99. Radio Detection of SGR 0501+4516: Retraction
  100. SGR 0501+4516: XMM-Newton monitoring schedule

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