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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"

24787 results found.

  1. Possible GRB-related phenomenon
  2. RXTE/ASM and IPN localization of GRB 000508B
  3. GRB000424, UBVRI field photometry
  4. GRB000418, UBVRI field photometry update
  5. The redshift of GRB 000418
  6. GRB000424, optical observations
  7. GRB 000429, optical observation
  8. GRB 000429, UBVRI field photometry
  9. IPN localization of GRB000429
  10. GRB 000418, UBVRI field photometry
  11. GRB 000418, optical observation
  12. GRB 000418, Optical Observation
  13. BeppoSAX GRB000424
  14. Correction to IPN error box for GRB000419
  15. IPN error box for GRB000418
  16. GRB000419 [IPN Position]
  17. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  18. GRB000416 BRJK observations
  19. 1SAXJ1715.0-7134 refined position
  20. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  21. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  22. Budget cuts in BeppoSAX operations: impact on GRB observations
  23. GRB 000408, optical observations
  24. GRB 991208, UBVRI field photometry
  25. GRB000301c results
  26. GRB000408, lotis optical observations
  27. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  28. GRB000408 [IPN Position]
  29. GRB000301C - Addendum to GCN 623
  30. GRB000326, Further VLA observations
  31. GRB 000326: Optical Observations
  32. GRB000326, Radio observations
  33. GRB000326 [IPN Position]
  34. GRB 000307 optical observations
  35. GRB000323 [IPN Position]
  36. GRB000315 [IPN Positions]
  37. GRB000313, Radio observations
  38. GRB 000313 - optical transient in the BATSE error box
  39. GRB 000307, Optical Observations
  40. GRB 000307, BVRI Field Photometry
  41. GRB 000301C: Optical Spectrum and Redshift
  42. GRB 000301C: Optical Spectrum and Redshift
  43. GRB 000301C: HST/STIS CCD Imaging of the field
  44. IPN error box for GRB000307
  45. GRB000301C, optical R-band observations
  46. GRB 000301C Optical Observations
  47. GRB 000301C: K' Observations
  48. GRB000301C - Host galaxy not detected in R (?)
  49. Optical observations of GRB000301c
  50. GRB000301C, Radio observations
  51. GRB000301C, Radio observations
  52. GRB000301C, near-infrared observations (JHK' imaging)
  53. GRB 000301c near-IR observations
  54. GRB 000301C, Optical Color
  55. GRB 000301C, UBVRI field photometry
  56. GRB000301C 250 GHz detection
  57. GRB000301C, near-infrared observations (JHK' photometry)
  58. GRB 000301C: OT confirmed
  59. GRB000301c optical observations
  60. GRB000301C
  61. GRB 000301C : Optical Candidate
  62. Radio observations of the error box of GRB000301A
  63. GRB000301A [IPN Position]
  64. GRB000226 [IPN Position]
  65. HST Observations of GRB 990712
  66. GRB 000214 near-IR observations
  67. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  68. GRB000210, Radio Observations
  69. GRB 000115, BVRI field photometry
  70. GRB000214: BeppoSAX GRBM and WFC Detection
  71. IPN annulus for GRB000214
  72. Optical observations of GRB000210
  73. GRB000210 X-ray afterglow
  74. GRB000214: X-ray afterglow candidate
  75. GRB000214 refined BeppoSAX-WFC position
  76. GRB 000210: BATSE Observations
  77. Optical observations of the Chandra X-ray source for GRB000210
  78. GRB000210, Radio Observations
  79. Optical candidate for GRB000210
  80. Chandra Observations of GRB000210 X-ray Afterglow
  81. GRB000210: possible afterglow detection with BeppoSAX NFI
  82. GRB000201, Radio Observations
  83. GRB000210: BeppoSAX GRBM and WFC Detection
  84. Optical observations of GRB000131
  85. GRB000201 Optical Observations
  86. GRB 000131 Optical Observations
  87. BATSE+IPN location of GRB000131
  88. IPN localization of GRB000131
  89. GRB 000126, optical observations
  90. IPN localization of GRB000126
  91. BATSE Observations of GRB000115
  92. GRB991216, UBVRIJHK field photometry
  93. GCN resumes full operations
  94. GRB 991216 VLBA Observations
  95. IPN error boxes for GRB991229
  96. GRB 991216: Detection of the Host and/or Absorber Galaxy
  97. IPN localization of GRB991226
  98. IPN error boxes for GRB991221
  99. GRB 991216 RXTE ASM Observations
  100. GRB 991216: Updated BATSE parameters

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