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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"

18435 results found.

  1. GRB 130408A: GROND detection of the afterglow
  2. GRB 130408A: Swift/UVOT Detection of the Optical Afterglow
  3. GRB 130408A: Liverpool Telescope Optical candidate detection
  4. GRB 130408A: Swift detection of a burst
  5. GRB 130407A Tiled Swift observations
  6. GRB 130211A: Retraction of afterglow candidate
  7. GRB 130327B: Suzaku WAM observation of the prompt emission
  8. Swift detection of IGR J18245-2452
  9. IPN Triangulation of GRB 130320B (very long/bright)
  10. Swift/XRT observation of GRB 130327B
  11. GRB 130306A: Confirmation of the X-ray Afterglow
  12. Swift Trigger 552142 is a noise event
  13. GRB 130327B: Fermi-LAT detection of a burst
  14. Swift Trigger 552142: a possible GRB
  15. GRB 130327A: Swift-BAT refined analysis
  16. GRB 130327A: Swift-XRT refined Analysis
  17. GRB 130327A: Swift/UVOT Upper Limits
  18. GRB 130327A: ISON-NM optical upper limit
  19. GRB 130325A Tiled Swift observations
  20. GRB 130327A: Enhanced Swift-XRT position
  21. GRB 130327A: PAIRITEL NIR Afterglow Candidate
  22. GRB 130325A: Fermi LAT detection
  23. GRB 130327A: Swift detection of a burst
  24. report: GRB 130315A: Zadko observatory - Gingin optical observations
  25. GRB 130315A: GROND afterglow candidate
  26. GRB 130305A: optical upper limit in Mondy observatory
  27. GRB 130315A: Swift/UVOT Upper Limits
  28. GRB 130313A: optical upper limit in CrAO
  29. GRB 130313A: optical upper limit in Mondy observatory
  30. GRB 130315A: SALT optical observations
  31. GRB 130315A: Swift-XRT refined Analysis
  32. Swift XRT observations of GRB 130310A
  33. GRB 130315A, Swift-BAT refined analysis
  34. GRB 130313A: Swift/UVOT Upper Limits
  35. GRB 130305A: PTF P48 optical upper limits
  36. GRB130315A BOOTES-3 optical limit
  37. GRB 130315A: Swift detection of a burst
  38. GRB 130305A: TLS Tautenburg observations
  39. GRB 130313A: RATIR Optical and NIR Observations
  40. GRB 130313A: Swift-BAT Spectral lag analysis
  41. GRB 130313A: Fading X-ray Afterglow
  42. Swift-BAT trigger 551030 is not astrophysical
  43. GRB 130313A: Swift-XRT refined Analysis
  44. GRB 130313A: simultaneous and follow-up optical observations at BOOTES-3 and BOOTES-4
  45. GRB 130313A: Swift-XRT detection of a possible X-ray afterglow
  46. GRB 130313A: Swift-BAT refined analysis
  47. GRB 130313A: Zadko observatory - Gingin optical observations
  48. GRB 130313A: MASTER-Net optical observations
  49. GRB 130313A: Swift detection of a short burst
  50. IPN Triangulation of GRB 130307A
  51. Swift XRT RETRACTION of GRB 130310A afterglow detection
  52. Swift XRT observations of GRB 130310A
  53. GRB 130306A: Swift Detection of a Possible Afterglow
  54. GRB 130306A: Swift-BAT refined analysis
  55. IPN triangulation of GRB 130228A
  56. GRB 130305A BAT refined circular
  57. GRB 130305A: Further Swift-XRT Observations
  58. Konus-Wind observation of GRB 130306A
  59. GRB 130305A: Optical Observations
  60. GRB 130306A: Fermi GBM observation
  61. GRB 130306A: MASTER-Net pre-Swift alert observation
  62. GRB 130305A: Swift/UVOT Upper Limit
  63. GRB 130305A: RATIR Observations
  64. GRB 130306A: Swift detection of a burst
  65. GRB 130305A: P60 Observations
  66. GRB 100615A: HST host detection and X-shooter redshift
  67. GRB 130305A: Swift/XRT detection of the afterglow
  68. Konus-Wind observation of GRB 130305A
  69. GRB 130305A: Fermi GBM observation
  70. GRB 130305A: Fermi LAT Detection
  71. GRB 130305A found in ground analysis of Swift/BAT data
  72. GRB 121128A: optical upper limit in Maidanak observatory
  73. GRB 130216A: Swift/UVOT Upper Limit
  74. GRB 130219A: Suzaku WAM observation of the prompt emission
  75. SGR 1806-20 outburst (trigger 549841), Swift-BAT refined analysis
  76. Trigger 549841: Swift detection of SGR1806-20
  77. GRB 130216B: Suzaku WAM observation of the prompt emission
  78. GRB 130216A: possible radio counterpart is steady field source
  79. GRB 130216A: Swift/XRT observations
  80. IPN Triangulation of GRB 130219A
  81. GRB 130215A: Suzaku WAM observation of the prompt emission
  82. GRB 130215A: PTF P48 optical detection
  83. GRB 130216B: Swift/XRT observations
  84. GRB 130216A: Further Swift-BAT refined analysis
  85. GRB 130216B: MASTER-Net early observation
  86. GRB 130216A: MASTER-Net early observations
  87. GRB 130216A: Fermi GBM observation
  88. GRB 130216B: Fermi GBM observation
  89. GRB 130216B BAT refined analysis
  90. GRB 130216A: Swift-BAT refined analysis
  91. GRB 130216A: TAROT La Silla observatory optical observations
  92. GRB 130216B: Burst found in ground analysis of BAT data
  93. GRB 130216A: OSN I-band observations
  94. GRB 130216A: Swift detection of a burst
  95. GRB 130215A: GROND Detection of the Optical/NIR Afterglow
  96. GRB 130215A: Fermi GBM detection
  97. GRB 130215A: RAPTOR Measurements
  98. GRB 130215A: Swift-BAT refined analysis
  99. GRB 130215A: TAROT La Silla observatory optical observations
  100. GRB 130215A: P60 Observations

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