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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').
  1. Radio observations of SGRs
  2. SGR1900+14 field optical observations
  3. GRB 980613 Near-IR observations
  4. GRB980613, optical observations
  5. GRB 980613: Optical transient and its host galaxy
  6. SGR1627-41, RXTE/ASM observations
  7. SGR1627-41, Refined IPN annulus location
  8. GRB 980613: Detection of the probable host galaxy
  9. Reduced error box of SGR 1627-41
  10. GRB 980613: BATSE Observations
  11. SGR1627-41, BeppoSAX-GRBM detections
  12. SGR 1627-41
  13. GRB 980613 Optical Observations
  14. GRB 980613 optical observations
  15. Discovery of a new SGR source, SGR1627-41
  16. GRB980613 Optical Observations
  17. GRB980613 observations from Palomar
  18. GRB980613 BeppoSAX-NFI follow up
  19. GRB 980613 new optical/IR observations
  20. GRB 980613 optical/IR obs.
  21. GRB980613 Near Infra-Red Observations
  22. GRB980611
  23. GRB980613, BeppoSAX WFC positions
  24. GRB971214 Secondary Standards
  25. SGR 1900+14
  26. GRB980519 Secondary Standards
  27. SGR1900+14
  28. SGR1900+14
  29. BATSE on-board GRB trigger change
  30. GRB 980519 Optical Observations
  31. GRB980519 optical observations
  32. GRB980519 I-band observations
  33. GRB 980519
  34. GRB980519 optical observations
  35. GRB 980519 Optical Observations
  36. GRB980519 BATSE Observations
  37. GRB970519, optical follow-up at Schmidt Calern
  38. GRB980519 optical observations
  39. GRB980519 Optical Observations
  40. GRB980519 Optical Observations
  41. GRB980519 IPN POSITION
  42. GRB980519 Optical Observations
  43. GRB 980519 Optical Observations
  44. GRB980519 optical observations
  45. GRB980515, BeppoSAX IAUC to be submitted
  46. BATSE on-board GRB trigger change
  47. GRB980519, BeppoSAX-WFC updated position
  48. GRB980519, BeppoSAX-WFC position
  49. GRB980515: SAX-WFC updated position
  50. BeppoSAX GRB ALERT: updated position of grb980515
  51. GRB 980425 Radio Light Curve
  52. GRB 980425 Brightness Temperature
  53. BSAX Observations of GRB980425 field
  54. IPN web site of GRBs
  55. GRB980425 BATSE observations
  56. SAX J0840.7+2248 Optical Observations
  57. GRB 980425 optical observations
  58. GRB980425: optical obs.
  59. GRB980425: Radio Observations
  60. GRB 980425 optical observations
  61. report on BSAX observations of GRB980425
  62. GRB 980425 optical observations
  63. GRB 980329 ROSAT observation
  64. GRB980326 X-ray Observations
  65. GRB980326, optical observations
  66. GRB980326, optical observations
  67. GRB980329, Fading IR counterpart to radio source
  68. GRByymmdd, Announcement of automation
  69. GRB980326 IPN annulus
  70. GRB980329
  71. GRB980329 Keck K-band observations
  72. GRB980329 sub-millimeter observations
  73. GRB980329 IPN annulus
  74. GRB980329 optical observations
  75. GRB980329 near-IR observations
  76. GRB980329 near-IR observations
  77. GRB980329 optical observations
  78. GRB980329 infrared observations
  79. GRB980329 optical observations
  80. GRB980326 optical observations
  81. GRB980329 optical observations
  82. GRB980329 VLA observations
  83. GRB980329 near IR observations
  84. GRB980329 optical observations
  85. GRB980329 optical observations
  86. GRB980329 optical observations
  87. GRB980326 optical observations
  88. GRB980326 optical observations
  89. GRB980326 optical observations
  90. GRB980326 optical observations
  91. GRB970508 SAO RAS optical observations
  92. Optical Observations of GRB 970508
  93. GRB 971214: Redshift from Keck Observations
  94. Near-IR follow-up on GRB 971227
  95. GRB971214: Keck R & I-band Observations
  96. GRB 971227: Optical Observations
  97. Optical Observations of the GRB 971227 field
  98. Optical Observations on GRB 971227
  99. GRB971227: Plaskett R-band observations
  100. GRB 971227: Optical clarifications

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