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

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