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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"
  1. GRB 980613: Optical transient and its host galaxy
  2. SGR1627-41, RXTE/ASM observations
  3. SGR1627-41, Refined IPN annulus location
  4. GRB 980613: Detection of the probable host galaxy
  5. Reduced error box of SGR 1627-41
  6. GRB 980613: BATSE Observations
  7. SGR1627-41, BeppoSAX-GRBM detections
  8. SGR 1627-41
  9. GRB 980613 Optical Observations
  10. GRB 980613 optical observations
  11. Discovery of a new SGR source, SGR1627-41
  12. GRB980613 Optical Observations
  13. GRB980613 observations from Palomar
  14. GRB980613 BeppoSAX-NFI follow up
  15. GRB 980613 new optical/IR observations
  16. GRB 980613 optical/IR obs.
  17. GRB980613 Near Infra-Red Observations
  18. GRB980611
  19. GRB980613, BeppoSAX WFC positions
  20. GRB971214 Secondary Standards
  21. SGR 1900+14
  22. GRB980519 Secondary Standards
  23. SGR1900+14
  24. SGR1900+14
  25. BATSE on-board GRB trigger change
  26. GRB 980519 Optical Observations
  27. GRB980519 optical observations
  28. GRB980519 I-band observations
  29. GRB 980519
  30. GRB980519 optical observations
  31. GRB 980519 Optical Observations
  32. GRB980519 BATSE Observations
  33. GRB970519, optical follow-up at Schmidt Calern
  34. GRB980519 optical observations
  35. GRB980519 Optical Observations
  36. GRB980519 Optical Observations
  37. GRB980519 IPN POSITION
  38. GRB980519 Optical Observations
  39. GRB 980519 Optical Observations
  40. GRB980519 optical observations
  41. GRB980515, BeppoSAX IAUC to be submitted
  42. BATSE on-board GRB trigger change
  43. GRB980519, BeppoSAX-WFC updated position
  44. GRB980519, BeppoSAX-WFC position
  45. GRB980515: SAX-WFC updated position
  46. BeppoSAX GRB ALERT: updated position of grb980515
  47. GRB 980425 Radio Light Curve
  48. GRB 980425 Brightness Temperature
  49. BSAX Observations of GRB980425 field
  50. IPN web site of GRBs
  51. GRB980425 BATSE observations
  52. SAX J0840.7+2248 Optical Observations
  53. GRB 980425 optical observations
  54. GRB980425: optical obs.
  55. GRB980425: Radio Observations
  56. GRB 980425 optical observations
  57. report on BSAX observations of GRB980425
  58. GRB 980425 optical observations
  59. GRB 980329 ROSAT observation
  60. GRB980326 X-ray Observations
  61. GRB980326, optical observations
  62. GRB980326, optical observations
  63. GRB980329, Fading IR counterpart to radio source
  64. GRByymmdd, Announcement of automation
  65. GRB980326 IPN annulus
  66. GRB980329
  67. GRB980329 Keck K-band observations
  68. GRB980329 sub-millimeter observations
  69. GRB980329 IPN annulus
  70. GRB980329 optical observations
  71. GRB980329 near-IR observations
  72. GRB980329 near-IR observations
  73. GRB980329 optical observations
  74. GRB980329 infrared observations
  75. GRB980329 optical observations
  76. GRB980326 optical observations
  77. GRB980329 optical observations
  78. GRB980329 VLA observations
  79. GRB980329 near IR observations
  80. GRB980329 optical observations
  81. GRB980329 optical observations
  82. GRB980329 optical observations
  83. GRB980326 optical observations
  84. GRB980326 optical observations
  85. GRB980326 optical observations
  86. GRB980326 optical observations
  87. GRB970508 SAO RAS optical observations
  88. Optical Observations of GRB 970508
  89. GRB 971214: Redshift from Keck Observations
  90. Near-IR follow-up on GRB 971227
  91. GRB971214: Keck R & I-band Observations
  92. GRB 971227: Optical Observations
  93. Optical Observations of the GRB 971227 field
  94. Optical Observations on GRB 971227
  95. GRB971227: Plaskett R-band observations
  96. GRB 971227: Optical clarifications
  97. Optical Observations for GRB 971227
  98. GRB971227: Further CAHA R-band images
  99. GRB971227: LOTIS observations
  100. GRB 971227: CAHA R-band images

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