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

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