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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. radio observations of GRB 981226
  2. GRB981220 B, R and I band observations
  3. GRB981226, BeppoSAX-NFI follow-up
  4. Optical Observations of GRB981226
  5. GRB 981220:Optical Observations
  6. GRB 981220 optical R and I observations
  7. GRB981226, BeppoSAX Christmas GRB
  8. GRB 981226 - Infrared Observations
  9. GRB 981226 optical observations
  10. GRB 981220
  11. GRB 981220, radio observations
  12. GRB981226 Optical Observation
  13. GRB 981220, radio observations
  14. GRB 981220: BeppoSAX/GRBM results
  15. GRB981220 I-band Observations
  16. GRB981220 Optical Observations
  17. GRB 981220
  18. GRB 981220 Optical Observations
  19. GRB 981220, optical observations
  20. GRB 980326/Host Galaxy
  21. GRB981220 IPN error box
  22. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  23. BeppoSAX NFI Observation of GRB980425
  24. GRB980329 R,I flux calibration and R,I,K upper limits
  25. GRB980425 Optical Follow-up
  26. GRB980425: X-ray revised positions
  27. GRB 980923 BATSE Observations
  28. SGR1900+14, BeppoSAX-GRBM observations
  29. GRB980703 Very Long Baseline Interferometry
  30. GRB970508 optical observations
  31. GRB971214, association with a Galactic star?
  32. Optical Observations of the Host Galaxy of GRB 980519
  33. GRB980519, Optical Observations
  34. GRB980703, Host galaxy multicolor photometry
  35. GRB980703 - BeppoSAX/GRBM detection
  36. GRB 980703 (NFI observations)
  37. GRB980703 optical photometry
  38. GRB 980703: BATSE Observations
  39. GRB980703 optical observations
  40. GRB980703: Radio transient
  41. GRB980703 H-band Observations
  42. GRB 980703: Spectrum of the proposed optical counterpart
  43. RXTE Observation of GRB 980706
  44. GRB980703: Spectrum of the proposed optical counterpart
  45. GRB980703 Transient Optical Follow-Up
  46. GRB980703: LOTIS observation at early times
  47. GRB980613 Optical Observations
  48. GRB 980703
  49. GRB980703 (I band observations)
  50. GRB 980703 H-band Observations
  51. GRB980703 (optical R observations)
  52. GRB980706
  53. GRB980703: radio source/optical transient
  54. BeppoSAX NFI observations of GRB 980703
  55. GRB 980703: ASM Position & Intensity
  56. GRB980703
  57. GRB980519 observation report
  58. GRB980703 optical followup
  59. SGR1627-41
  60. Radio observations of SGRs
  61. SGR1900+14 field optical observations
  62. GRB 980613 Near-IR observations
  63. GRB980613, optical observations
  64. GRB 980613: Optical transient and its host galaxy
  65. SGR1627-41, RXTE/ASM observations
  66. SGR1627-41, Refined IPN annulus location
  67. GRB 980613: Detection of the probable host galaxy
  68. Reduced error box of SGR 1627-41
  69. GRB 980613: BATSE Observations
  70. SGR1627-41, BeppoSAX-GRBM detections
  71. SGR 1627-41
  72. GRB 980613 Optical Observations
  73. GRB 980613 optical observations
  74. Discovery of a new SGR source, SGR1627-41
  75. GRB980613 Optical Observations
  76. GRB980613 observations from Palomar
  77. GRB980613 BeppoSAX-NFI follow up
  78. GRB 980613 new optical/IR observations
  79. GRB 980613 optical/IR obs.
  80. GRB980613 Near Infra-Red Observations
  81. GRB980611
  82. GRB980613, BeppoSAX WFC positions
  83. GRB971214 Secondary Standards
  84. SGR 1900+14
  85. GRB980519 Secondary Standards
  86. SGR1900+14
  87. SGR1900+14
  88. BATSE on-board GRB trigger change
  89. GRB 980519 Optical Observations
  90. GRB980519 optical observations
  91. GRB980519 I-band observations
  92. GRB 980519
  93. GRB980519 optical observations
  94. GRB 980519 Optical Observations
  95. GRB980519 BATSE Observations
  96. GRB970519, optical follow-up at Schmidt Calern
  97. GRB980519 optical observations
  98. GRB980519 Optical Observations
  99. GRB980519 Optical Observations
  100. GRB980519 IPN POSITION

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