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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"

22062 results found.

  1. GRB 990123 Optical Follow-up
  2. GRB990123, early optical counterpart detection
  3. GRB 990123, Radio observations
  4. SN 1999E & GRB 980919
  5. Possible identification of SN1999E with GRB980910
  6. Optical Observations of GRB 981220
  7. GRB981220
  8. GRB981220, Correction to GCN 179
  9. GRB981220, Optical Observations
  10. GRB 981220 Optical observations
  11. GRB 981226 Optical Observations
  12. GRB 980613: Spectroscopy of the host galaxy
  13. GRB981226, sub-millimeter observations
  14. GRB981220, sub-millimeter observations
  15. GRB 981220 and GRB 981226, optical observations
  16. GRB981226 Optical Observations
  17. GRB 981226 radio observations
  18. GRB 981226
  19. GRB 981226 optical observations
  20. radio observations of GRB 981226
  21. GRB981220 B, R and I band observations
  22. Optical Observations of GRB981226
  23. GRB 981220:Optical Observations
  24. GRB 981220 optical R and I observations
  25. GRB981226, BeppoSAX Christmas GRB
  26. GRB 981226 - Infrared Observations
  27. GRB 981226 optical observations
  28. GRB 981220
  29. GRB 981220, radio observations
  30. GRB981226 Optical Observation
  31. GRB 981220, radio observations
  32. GRB981220 I-band Observations
  33. GRB981220 Optical Observations
  34. GRB 981220
  35. GRB 981220 Optical Observations
  36. GRB 981220, optical observations
  37. GRB 980326/Host Galaxy
  38. GRB980329 R,I flux calibration and R,I,K upper limits
  39. GRB980425 Optical Follow-up
  40. GRB980425: X-ray revised positions
  41. GRB 980923 BATSE Observations
  42. SGR1900+14, BeppoSAX-GRBM observations
  43. GRB980703 Very Long Baseline Interferometry
  44. GRB970508 optical observations
  45. Optical Observations of the Host Galaxy of GRB 980519
  46. GRB980519, Optical Observations
  47. GRB 980703 (NFI observations)
  48. GRB980703 optical photometry
  49. GRB 980703: BATSE Observations
  50. GRB980703 optical observations
  51. GRB980703 H-band Observations
  52. GRB 980703: Spectrum of the proposed optical counterpart
  53. GRB980703: Spectrum of the proposed optical counterpart
  54. GRB980613 Optical Observations
  55. GRB980703 (I band observations)
  56. GRB 980703 H-band Observations
  57. GRB980703 (optical R observations)
  58. GRB980703: radio source/optical transient
  59. BeppoSAX NFI observations of GRB 980703
  60. GRB980703 optical followup
  61. Radio observations of SGRs
  62. SGR1900+14 field optical observations
  63. GRB 980613 Near-IR observations
  64. GRB980613, optical observations
  65. SGR1627-41, RXTE/ASM observations
  66. GRB 980613: Detection of the probable host galaxy
  67. Reduced error box of SGR 1627-41
  68. GRB 980613: BATSE Observations
  69. GRB 980613 Optical Observations
  70. GRB 980613 optical observations
  71. Discovery of a new SGR source, SGR1627-41
  72. GRB980613 Optical Observations
  73. GRB980613 observations from Palomar
  74. GRB 980613 new optical/IR observations
  75. GRB 980613 optical/IR obs.
  76. GRB980613 Near Infra-Red Observations
  77. GRB971214 Secondary Standards
  78. SGR 1900+14
  79. GRB980519 Secondary Standards
  80. SGR1900+14
  81. SGR1900+14
  82. GRB 980519 Optical Observations
  83. GRB980519 optical observations
  84. GRB980519 I-band observations
  85. GRB 980519
  86. GRB980519 optical observations
  87. GRB 980519 Optical Observations
  88. GRB980519 BATSE Observations
  89. GRB980519 optical observations
  90. GRB980519 Optical Observations
  91. GRB980519 Optical Observations
  92. GRB980519 Optical Observations
  93. GRB 980519 Optical Observations
  94. GRB980519 optical observations
  95. GRB 980425 Brightness Temperature
  96. BSAX Observations of GRB980425 field
  97. GRB980425 BATSE observations
  98. SAX J0840.7+2248 Optical Observations
  99. GRB 980425 optical observations
  100. GRB980425: optical obs.

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