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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"

22053 results found.

  1. IPN localization of GRB000429
  2. GRB 000418, optical observation
  3. GRB000424 Optical Observations
  4. GRB000424, optical observations
  5. GRB000424, optical observations
  6. GRB 000424, Optical Observations
  7. GRB 000418, Optical Observation
  8. GRB000418, near-infrared observations
  9. IPN error box for GRB000418
  10. GRB000419 [IPN Position]
  11. GRB000416 Optical Observations
  12. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  13. GRB000416 BRJK observations
  14. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  15. Budget cuts in BeppoSAX operations: impact on GRB observations
  16. GRB 000408, optical observations
  17. Refined IPN error box for GRB000408
  18. GRB000408: Optical CCD Observations from MIRO
  19. GRB000408, lotis optical observations
  20. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  21. GRB000408 [IPN Position]
  22. GRB000326 Optical Observations
  23. GRB000301C - R magnitude lower limit
  24. GRB000326, Further VLA observations
  25. GRB 000323, optical observations
  26. GRB 000326: Optical Observations
  27. GRB000326, Radio observations
  28. GRB000326 [IPN Position]
  29. GRB 000307 optical observations
  30. GRB000323 [IPN Position]
  31. GRB000315 [IPN Positions]
  32. GRB000313, Radio observations
  33. GRB 000313 - optical transient in the BATSE error box
  34. GRB 000307, Optical Observations
  35. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  36. GRB 000301C: HST/STIS CCD Imaging of the field
  37. IPN error box for GRB000307
  38. GRB 000301c: K' observations
  39. GRB000301C, optical R-band observations
  40. GRB000301c - R photometry and nearby faint source confirmation
  41. GRB 000301C, Optical Observation
  42. GRB 000301c: K' observations
  43. GRB 000301C Optical Observations
  44. GRB 000301C: K' Observations
  45. GRB000301C OT candidate optical observations
  46. GRB000301C - Host galaxy not detected in R (?)
  47. Optical observations of GRB000301c
  48. GRB000301C, Radio observations
  49. GRB000301C, Radio observations
  50. GRB000301C optical observations
  51. GRB000301C, near-infrared observations (JHK' imaging)
  52. GRB 000301c near-IR observations
  53. GRB000301C, optical observations
  54. GRB 000301C, Optical Observation
  55. GRB000301C, near-infrared observations (JHK' photometry)
  56. GRB000301c optical observations
  57. GRB 000301A, Radio Observations
  58. GRB000301C, optical observations
  59. GRB000301c, near-infrared observations
  60. Radio observations of the error box of GRB000301A
  61. GRB000301C: RXTE/ASM and IPN localizations
  62. GRB000301A [IPN Position]
  63. GRB000226 [IPN Position]
  64. HST Observations of GRB 990712
  65. GRB 000214 near-IR observations
  66. GRB 000115 Optical observations
  67. GRB 000214, Radio Observations
  68. GRB000210, Radio Observations
  69. Optical observations of GRB000210
  70. GRB 000210: BATSE Observations
  71. Optical observations of the Chandra X-ray source for GRB000210
  72. GRB000210, Radio Observations
  73. Optical candidate for GRB000210
  74. Chandra Observations of GRB000210 X-ray Afterglow
  75. GRB000201, Radio Observations
  76. Optical observations of GRB000131
  77. GRB000201 Optical Observations
  78. GRB 000201: TAROT optical observations
  79. GRB 000131 Optical Observations
  80. GRB000126 Optical Observations
  81. GRB 991208, radio observations
  82. BATSE+IPN location of GRB000131
  83. IPN localization of GRB000131
  84. GRB 000126, optical observations
  85. GRB000126, optical observations
  86. IPN localization of GRB000126
  87. GRB 000115 Optical observations
  88. BATSE Observations of GRB000115
  89. IPN annulus for GRB000115
  90. GRB991216, UBVRIJHK field photometry
  91. GRB991216 late optical observation
  92. Single IPN error box for GRB991229
  93. GRB 991216 VLBA Observations
  94. BEPPOSAX GRBM Localization of GRB991226
  95. IPN error boxes for GRB991229
  96. GRB 991216: J band spectrophotometry
  97. IPN localization of GRB991226
  98. Single IPN error box for GRB991221
  99. IPN error boxes for GRB991221
  100. GRB 991216 RXTE ASM Observations

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Download all Circulars as a .tar.gz archive (updated once a day):
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