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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"

41579 results found.

  1. GRB 990806, optical observations
  2. GRB 990806, Optical Observations
  3. GRB990806 UBVRIJHK observations
  4. GRB990806: possible X-ray afterglow, BeppoSAX
  5. BeppoSAX ALERT GRB990806: Summer GRB
  6. GRB 990712 Optical Observations
  7. GRB990705: No Evidence for Neutrino Signal
  8. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  9. VLT spectrum of GRB990712
  10. GRB 990712
  11. Late-time HST/STIS Observations of GRB 990510
  12. Refined BeppoSAX-WFC position of GRB990712
  13. BeppoSAX NFI Observation of GRB990705
  14. BeppoSAX NFI Observation of GRB990705
  15. Updated Astrometry for the IR Counterpart of GRB990705
  16. GRB 990705, R-band observations
  17. Updated IPN localization of GRB990705
  18. IPN localization of GRB990704
  19. IPN localization of GRB990705
  20. Infrared and Optical Observations of GRB990705
  21. GRB 990705, radio observations
  22. GRB990704: SAX-NFI results summary
  23. BeppoSAX GRB990705: possible X-ray afterglow
  24. GRB 990704 X-ray Observations
  25. GRB 990704 Optical Observations
  26. GRB990704
  27. GRB990705: Intriguing Positional Coincidences
  28. GRB990704
  29. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  30. GRB990704, optical observations
  31. GRB990704: possible X-ray afterglow
  32. Identification of a possible optical counterpart for GRB990704
  33. GRB990704
  34. Refined BeppoSAX-WFC position of GRB990704
  35. GRB990704: BeppoSAX detection
  36. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  37. Optical Observations of GRB990627
  38. GRB 990627, radio observations
  39. GRB990627: BeppoSAX-WFC final location
  40. BeppoSAX: GRB990625
  41. Late-time HST/STIS Observation of GRB 990123
  42. GRB 990506 - clarification to GCN 352
  43. GRB 990506 - Optical Observations
  44. Optical Observations of GRB 990506
  45. GRB 990506 Radio Transient
  46. GRB990527 Optical Observations
  47. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  48. IPN error box for GRB990527
  49. Late Afterglows of GRBs 990510, 990123
  50. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  51. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  52. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  53. GRB 990506 optical observation
  54. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  55. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  56. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  57. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  58. radio observations of X-ray/GRB transient field
  59. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  60. Optical report on X-ray/GRB transient
  61. radio detection of X-ray/GRB transient
  62. BeppoSAX: A new fast X-ray transient
  63. GRB 990510: optical observations
  64. GRB990510: photometric and spectroscopic observations with the VLT
  65. GRB 990510: optical linear polarization
  66. GRB 990510: optical observations
  67. GRB990510, VI observations
  68. GRB 990506 R band observations
  69. GRB990510: X-ray afterglow
  70. GRB 990510: optical observation
  71. VLT spectrum of GRB990510
  72. GRB 990510: Broad Band Break
  73. GRB 990510: BATSE Observations
  74. GRB 990510 Optical Observations
  75. GRB 990510, BVI photometry
  76. GRB 990510 optical observations
  77. GRB 990510: BeppoSAX/GRBM observations
  78. GRB990510 optical observations
  79. GRB990510
  80. GRB 990510 optical observations
  81. GRB 990510 optical observations
  82. GRB990510: NFI X-ray source
  83. GRB 990510 optical observations
  84. IPN localization of GRB990510
  85. GRB 990506 Radio Observations
  86. GRB 990123, optical monitoring
  87. GRB 990506: BATSE Observations
  88. GRB 990506, optical observations
  89. GRB 990510: Final BeppoSAX-WFC Coordinates
  90. GRB 990506, Optical Observations
  91. GRB 990506, optical observations
  92. GRB990506 observation plan
  93. Refined IPN error box for GRB990506
  94. GRB 990506: Limits on the possible optical transient
  95. GRB 990506, armchair astronomy
  96. GRB 990506, optical observations from +1 to +3 hours
  97. GRB 990506, optical observations
  98. GRB990506 Optical observations
  99. GRB990506 observation plan
  100. New IPN/RXTE error box for GRB990506

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