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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. GRB981220, Optical Observations
  2. GRB 981220 Optical observations
  3. GRB 981226 Optical Observations
  4. GRB 980613: Spectroscopy of the host galaxy
  5. GRB981226, sub-millimeter observations
  6. GRB981220, sub-millimeter observations
  7. GRB 981220 and GRB 981226, optical observations
  8. GRB981226 Optical Observations
  9. GRB981226 BeppoSAX follow up
  10. GRB 981226 radio observations
  11. GRB 981226
  12. GRB 981226 optical observations
  13. radio observations of GRB 981226
  14. GRB981220 B, R and I band observations
  15. GRB981226, BeppoSAX-NFI follow-up
  16. Optical Observations of GRB981226
  17. GRB 981220:Optical Observations
  18. GRB 981220 optical R and I observations
  19. GRB981226, BeppoSAX Christmas GRB
  20. GRB 981226 - Infrared Observations
  21. GRB 981226 optical observations
  22. GRB 981220
  23. GRB 981220, radio observations
  24. GRB981226 Optical Observation
  25. GRB 981220, radio observations
  26. GRB 981220: BeppoSAX/GRBM results
  27. GRB981220 I-band Observations
  28. GRB981220 Optical Observations
  29. GRB 981220
  30. GRB 981220 Optical Observations
  31. GRB 981220, optical observations
  32. GRB 980326/Host Galaxy
  33. GRB981220 IPN error box
  34. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  35. BeppoSAX NFI Observation of GRB980425
  36. GRB980329 R,I flux calibration and R,I,K upper limits
  37. GRB980425 Optical Follow-up
  38. GRB980425: X-ray revised positions
  39. GRB 980923 BATSE Observations
  40. SGR1900+14, BeppoSAX-GRBM observations
  41. GRB980703 Very Long Baseline Interferometry
  42. GRB970508 optical observations
  43. GRB971214, association with a Galactic star?
  44. Optical Observations of the Host Galaxy of GRB 980519
  45. GRB980519, Optical Observations
  46. GRB980703, Host galaxy multicolor photometry
  47. GRB980703 - BeppoSAX/GRBM detection
  48. GRB 980703 (NFI observations)
  49. GRB980703 optical photometry
  50. GRB 980703: BATSE Observations
  51. GRB980703 optical observations
  52. GRB980703: Radio transient
  53. GRB980703 H-band Observations
  54. GRB 980703: Spectrum of the proposed optical counterpart
  55. RXTE Observation of GRB 980706
  56. GRB980703: Spectrum of the proposed optical counterpart
  57. GRB980703 Transient Optical Follow-Up
  58. GRB980703: LOTIS observation at early times
  59. GRB980613 Optical Observations
  60. GRB 980703
  61. GRB980703 (I band observations)
  62. GRB 980703 H-band Observations
  63. GRB980703 (optical R observations)
  64. GRB980706
  65. GRB980703: radio source/optical transient
  66. BeppoSAX NFI observations of GRB 980703
  67. GRB 980703: ASM Position & Intensity
  68. GRB980703
  69. GRB980519 observation report
  70. GRB980703 optical followup
  71. SGR1627-41
  72. Radio observations of SGRs
  73. SGR1900+14 field optical observations
  74. GRB 980613 Near-IR observations
  75. GRB980613, optical observations
  76. GRB 980613: Optical transient and its host galaxy
  77. SGR1627-41, RXTE/ASM observations
  78. SGR1627-41, Refined IPN annulus location
  79. GRB 980613: Detection of the probable host galaxy
  80. Reduced error box of SGR 1627-41
  81. GRB 980613: BATSE Observations
  82. SGR1627-41, BeppoSAX-GRBM detections
  83. SGR 1627-41
  84. GRB 980613 Optical Observations
  85. GRB 980613 optical observations
  86. Discovery of a new SGR source, SGR1627-41
  87. GRB980613 Optical Observations
  88. GRB980613 observations from Palomar
  89. GRB980613 BeppoSAX-NFI follow up
  90. GRB 980613 new optical/IR observations
  91. GRB 980613 optical/IR obs.
  92. GRB980613 Near Infra-Red Observations
  93. GRB980611
  94. GRB980613, BeppoSAX WFC positions
  95. GRB971214 Secondary Standards
  96. SGR 1900+14
  97. GRB980519 Secondary Standards
  98. SGR1900+14
  99. SGR1900+14
  100. BATSE on-board GRB trigger change

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Download all Circulars as a .tar.gz archive (updated once a day):
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