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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, radio observations
  2. GRB 981220: BeppoSAX/GRBM results
  3. GRB981220 I-band Observations
  4. GRB981220 Optical Observations
  5. GRB 981220
  6. GRB 981220 Optical Observations
  7. GRB 981220, optical observations
  8. GRB 980326/Host Galaxy
  9. GRB981220 IPN error box
  10. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  11. BeppoSAX NFI Observation of GRB980425
  12. GRB980329 R,I flux calibration and R,I,K upper limits
  13. GRB980425 Optical Follow-up
  14. GRB980425: X-ray revised positions
  15. GRB 980923 BATSE Observations
  16. SGR1900+14, BeppoSAX-GRBM observations
  17. GRB980703 Very Long Baseline Interferometry
  18. GRB970508 optical observations
  19. GRB971214, association with a Galactic star?
  20. Optical Observations of the Host Galaxy of GRB 980519
  21. GRB980519, Optical Observations
  22. GRB980703, Host galaxy multicolor photometry
  23. GRB980703 - BeppoSAX/GRBM detection
  24. GRB 980703 (NFI observations)
  25. GRB980703 optical photometry
  26. GRB 980703: BATSE Observations
  27. GRB980703 optical observations
  28. GRB980703: Radio transient
  29. GRB980703 H-band Observations
  30. GRB 980703: Spectrum of the proposed optical counterpart
  31. RXTE Observation of GRB 980706
  32. GRB980703: Spectrum of the proposed optical counterpart
  33. GRB980703 Transient Optical Follow-Up
  34. GRB980703: LOTIS observation at early times
  35. GRB980613 Optical Observations
  36. GRB 980703
  37. GRB980703 (I band observations)
  38. GRB 980703 H-band Observations
  39. GRB980703 (optical R observations)
  40. GRB980706
  41. GRB980703: radio source/optical transient
  42. BeppoSAX NFI observations of GRB 980703
  43. GRB 980703: ASM Position & Intensity
  44. GRB980703
  45. GRB980519 observation report
  46. GRB980703 optical followup
  47. SGR1627-41
  48. Radio observations of SGRs
  49. SGR1900+14 field optical observations
  50. GRB 980613 Near-IR observations
  51. GRB980613, optical observations
  52. GRB 980613: Optical transient and its host galaxy
  53. SGR1627-41, RXTE/ASM observations
  54. SGR1627-41, Refined IPN annulus location
  55. GRB 980613: Detection of the probable host galaxy
  56. Reduced error box of SGR 1627-41
  57. GRB 980613: BATSE Observations
  58. SGR1627-41, BeppoSAX-GRBM detections
  59. SGR 1627-41
  60. GRB 980613 Optical Observations
  61. GRB 980613 optical observations
  62. Discovery of a new SGR source, SGR1627-41
  63. GRB980613 Optical Observations
  64. GRB980613 observations from Palomar
  65. GRB980613 BeppoSAX-NFI follow up
  66. GRB 980613 new optical/IR observations
  67. GRB 980613 optical/IR obs.
  68. GRB980613 Near Infra-Red Observations
  69. GRB980611
  70. GRB980613, BeppoSAX WFC positions
  71. GRB971214 Secondary Standards
  72. SGR 1900+14
  73. GRB980519 Secondary Standards
  74. SGR1900+14
  75. SGR1900+14
  76. BATSE on-board GRB trigger change
  77. GRB 980519 Optical Observations
  78. GRB980519 optical observations
  79. GRB980519 I-band observations
  80. GRB 980519
  81. GRB980519 optical observations
  82. GRB 980519 Optical Observations
  83. GRB980519 BATSE Observations
  84. GRB970519, optical follow-up at Schmidt Calern
  85. GRB980519 optical observations
  86. GRB980519 Optical Observations
  87. GRB980519 Optical Observations
  88. GRB980519 IPN POSITION
  89. GRB980519 Optical Observations
  90. GRB 980519 Optical Observations
  91. GRB980519 optical observations
  92. GRB980515, BeppoSAX IAUC to be submitted
  93. BATSE on-board GRB trigger change
  94. GRB980519, BeppoSAX-WFC updated position
  95. GRB980519, BeppoSAX-WFC position
  96. GRB980515: SAX-WFC updated position
  97. BeppoSAX GRB ALERT: updated position of grb980515
  98. GRB 980425 Radio Light Curve
  99. GRB 980425 Brightness Temperature
  100. BSAX Observations of GRB980425 field

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