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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"

24603 results found.

  1. GRB 981220 Optical observations
  2. GRB 981226 Optical Observations
  3. GRB 981220 and GRB 981226, optical observations
  4. GRB981226 Optical Observations
  5. GRB981226 BeppoSAX follow up
  6. GRB 981226
  7. GRB 981226 optical observations
  8. GRB981220 B, R and I band observations
  9. Optical Observations of GRB981226
  10. GRB 981220:Optical Observations
  11. GRB 981226 optical observations
  12. GRB 981220
  13. GRB 981220, radio observations
  14. GRB981220 I-band Observations
  15. GRB 981220
  16. GRB 980326/Host Galaxy
  17. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  18. BeppoSAX NFI Observation of GRB980425
  19. GRB980329 R,I flux calibration and R,I,K upper limits
  20. GRB980425 Optical Follow-up
  21. GRB 980923 BATSE Observations
  22. SGR1900+14, BeppoSAX-GRBM observations
  23. GRB970508 optical observations
  24. GRB971214, association with a Galactic star?
  25. GRB980519, Optical Observations
  26. GRB980703 - BeppoSAX/GRBM detection
  27. GRB980703 optical photometry
  28. GRB 980703: BATSE Observations
  29. GRB980703 optical observations
  30. GRB980703: Radio transient
  31. GRB 980703: Spectrum of the proposed optical counterpart
  32. GRB980703 Transient Optical Follow-Up
  33. GRB980703: LOTIS observation at early times
  34. GRB980613 Optical Observations
  35. GRB980703 (I band observations)
  36. BeppoSAX NFI observations of GRB 980703
  37. GRB980519 observation report
  38. GRB980703 optical followup
  39. Radio observations of SGRs
  40. SGR1900+14 field optical observations
  41. GRB980613, optical observations
  42. GRB 980613: Optical transient and its host galaxy
  43. SGR1627-41, RXTE/ASM observations
  44. GRB 980613: Detection of the probable host galaxy
  45. Reduced error box of SGR 1627-41
  46. GRB 980613: BATSE Observations
  47. GRB 980613 Optical Observations
  48. GRB 980613 optical observations
  49. Discovery of a new SGR source, SGR1627-41
  50. GRB980613 Optical Observations
  51. GRB980613 observations from Palomar
  52. GRB 980613 optical/IR obs.
  53. GRB980613 Near Infra-Red Observations
  54. GRB971214 Secondary Standards
  55. GRB980519 Secondary Standards
  56. BATSE on-board GRB trigger change
  57. GRB 980519 Optical Observations
  58. GRB 980519
  59. GRB980519 optical observations
  60. GRB 980519 Optical Observations
  61. GRB980519 BATSE Observations
  62. GRB980519 Optical Observations
  63. GRB980519 Optical Observations
  64. GRB 980519 Optical Observations
  65. GRB980515, BeppoSAX IAUC to be submitted
  66. BSAX Observations of GRB980425 field
  67. IPN web site of GRBs
  68. GRB980425 BATSE observations
  69. SAX J0840.7+2248 Optical Observations
  70. GRB980425: optical obs.
  71. GRB980425: Radio Observations
  72. report on BSAX observations of GRB980425
  73. GRB 980329 ROSAT observation
  74. GRB980326 X-ray Observations
  75. GRB980326, optical observations
  76. GRB980326, optical observations
  77. GRB980329, Fading IR counterpart to radio source
  78. GRB980329 Keck K-band observations
  79. GRB980329 sub-millimeter observations
  80. GRB980329 optical observations
  81. GRB980329 near-IR observations
  82. GRB980329 near-IR observations
  83. GRB980326 optical observations
  84. GRB980329 optical observations
  85. GRB980329 VLA observations
  86. GRB980329 optical observations
  87. GRB980329 optical observations
  88. GRB980326 optical observations
  89. GRB980326 optical observations
  90. Optical Observations of GRB 970508
  91. Near-IR follow-up on GRB 971227
  92. Optical Observations of the GRB 971227 field
  93. Optical Observations on GRB 971227
  94. GRB971227: Plaskett R-band observations
  95. GRB 971227: Optical clarifications
  96. GRB971227: Further CAHA R-band images
  97. GRB971227: LOTIS observations
  98. GRB971214: Optical Observations and Calibrations
  99. GRB 971214: Optical Observations
  100. Radio Observations of GRB 971214 at the VLA

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