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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"

38354 results found.

  1. BeppoSAX NFI Observation of GRB990705
  2. BeppoSAX NFI Observation of GRB990705
  3. Updated Astrometry for the IR Counterpart of GRB990705
  4. GRB 990705, R-band observations
  5. Updated IPN localization of GRB990705
  6. IPN localization of GRB990704
  7. IPN localization of GRB990705
  8. Infrared and Optical Observations of GRB990705
  9. GRB 990705, radio observations
  10. GRB990704: SAX-NFI results summary
  11. GRB990704 radio and optical observations
  12. BeppoSAX GRB990705: possible X-ray afterglow
  13. GRB 990704 X-ray Observations
  14. GRB 990704 Optical Observations
  15. GRB 990704, optical observations
  16. GRB990704
  17. GRB990705: Intriguing Positional Coincidences
  18. GRB990704
  19. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  20. GRB990704, optical observations
  21. GRB990704: possible X-ray afterglow
  22. Identification of a possible optical counterpart for GRB990704
  23. GRB990704
  24. Refined BeppoSAX-WFC position of GRB990704
  25. GRB990704: BeppoSAX detection
  26. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  27. Optical Observations of GRB990627
  28. GRB 990627, radio observations
  29. GRB990627: BeppoSAX-WFC final location
  30. BeppoSAX: GRB990625
  31. Late-time HST/STIS Observation of GRB 990123
  32. GRB 990506 - Optical Observations
  33. Optical Observations of GRB 990506
  34. GRB990527 Optical Observations
  35. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  36. IPN error box for GRB990527
  37. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  38. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  39. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  40. GRB 990506 optical observation
  41. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  42. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  43. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  44. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  45. radio observations of X-ray/GRB transient field
  46. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  47. Optical report on X-ray/GRB transient
  48. radio detection of X-ray/GRB transient
  49. BeppoSAX: A new fast X-ray transient
  50. GRB 990510: optical observations
  51. GRB990510: photometric and spectroscopic observations with the VLT
  52. GRB 990510: optical linear polarization
  53. GRB990510, VI observations
  54. GRB 990506 R band observations
  55. GRB990510: X-ray afterglow
  56. VLT spectrum of GRB990510
  57. GRB 990510: Broad Band Break
  58. GRB 990510: BATSE Observations
  59. GRB990510: optical observation
  60. GRB 990510 Optical Observations
  61. GRB 990510, BVI photometry
  62. GRB 990510 optical observations
  63. GRB 990510: BeppoSAX/GRBM observations
  64. GRB990510 optical observations
  65. GRB 990510 optical observations
  66. GRB 990510 optical observations
  67. GRB990510: NFI X-ray source
  68. GRB 990510 optical observations
  69. IPN localization of GRB990510
  70. GRB 990506 Radio Observations
  71. GRB 990123, optical monitoring
  72. GRB 990506: BATSE Observations
  73. GRB 990510: Final BeppoSAX-WFC Coordinates
  74. GRB 990506, Optical Observations
  75. GRB 990506 optical observations
  76. GRB 990506 optical observations
  77. GRB 990506, optical observations
  78. Refined IPN error box for GRB990506
  79. GRB 990506: Limits on the possible optical transient
  80. GRB 990506, armchair astronomy
  81. GRB 990506, optical observations from +1 to +3 hours
  82. GRB 990506, optical observations
  83. GRB990506 Optical observations
  84. New IPN/RXTE error box for GRB990506
  85. IPN localization for GRB990506
  86. GRB 970228: Redshift and properties of the host galaxy
  87. IPN localization of GRB990427
  88. GRB981220 VLBA observations
  89. GRB980425 Optical observations of exponential decline at late time
  90. GRB990321 REFINED IPN ANNULUS
  91. GRB990323 PRECISE IPN POSITION
  92. GRB990321 IPN TRIANGULATION
  93. GRB 990316 Optical Observations
  94. GRB 990316, Radio observations
  95. GRB 990316, Optical observations
  96. GRB990316, Optical observations
  97. GRB 990316 optical observations
  98. GRB990316: simultaneous optical observation
  99. GRB990316 - Optical null results
  100. ASM/IPN error box for GRB 990308 (BATSE #7457)

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