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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"

45437 results found.

  1. GRB 000418, Optical Observation
  2. GRB000418, near-infrared observations
  3. BeppoSAX GRB000424
  4. Correction to IPN error box for GRB000419
  5. IPN error box for GRB000418
  6. GRB000419 [IPN Position]
  7. GRB000416 Optical Observations
  8. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  9. GRB000416 BRJK observations
  10. 1SAXJ1715.0-7134 refined position
  11. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  12. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  13. Budget cuts in BeppoSAX operations: impact on GRB observations
  14. GRB 000408, optical observations
  15. Refined IPN error box for GRB000408
  16. GRB 991208, UBVRI field photometry
  17. GRB000301c results
  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 - Addendum to GCN 623
  24. GRB000301C - R magnitude lower limit
  25. GRB000326, Further VLA observations
  26. GRB 000323, optical observations
  27. GRB 000326: Optical Observations
  28. GRB000326, Radio observations
  29. GRB000326 [IPN Position]
  30. GRB 000307 optical observations
  31. GRB000323 [IPN Position]
  32. Single error box for GRB000315
  33. GRB000315 [IPN Positions]
  34. GRB000313, Radio observations
  35. GRB 000313 - optical transient in the BATSE error box
  36. GRB000301C - B and R photometry
  37. GRB000301C - R photometry
  38. GRB 000307, Optical Observations
  39. GRB 000307, BVRI Field Photometry
  40. GRB 000301C: Optical Spectrum and Redshift
  41. GRB 000301C: Optical Spectrum and Redshift
  42. GRB 000301C: A Precise Redshift Determination
  43. GRB 000301C, Optical Observation
  44. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  45. GRB 000301C: HST/STIS CCD Imaging of the field
  46. IPN error box for GRB000307
  47. GRB 000301c: K' observations
  48. GRB000301C, optical R-band observations
  49. GRB000301c - R photometry and nearby faint source confirmation
  50. GRB 000301C, Optical Observation
  51. GRB 000301c: K' observations
  52. GRB 000301C Optical Observations
  53. GRB 000301C: K' Observations
  54. GRB000301C OT candidate optical observations
  55. GRB000301C - Host galaxy not detected in R (?)
  56. Optical observations of GRB000301c
  57. GRB000301C, Radio observations
  58. GRB000301C, Radio observations
  59. GRB000301C optical observations
  60. GRB000301C, near-infrared observations (JHK' imaging)
  61. GRB 000301c near-IR observations
  62. GRB 000301C, Optical Color
  63. GRB000301C, Optical Spectroscopy
  64. GRB 000301C, UBVRI field photometry
  65. GRB 000301C, Optical Observation
  66. GRB000301C, optical observations
  67. GRB000301C 250 GHz detection
  68. GRB 000301C R-band observation
  69. GRB 000301C, Optical Observation
  70. GRB000301C, near-infrared observations (JHK' photometry)
  71. GRB 000301C: OT confirmed
  72. GRB000301c optical observations
  73. GRB 000301A, Radio Observations
  74. GRB000301C, optical observations
  75. GRB000301c, near-infrared observations
  76. GRB000301C
  77. GRB 000301C : Optical Candidate
  78. Radio observations of the error box of GRB000301A
  79. GRB000301C: RXTE/ASM and IPN localizations
  80. GRB000226 [IPN Position]
  81. HST Observations of GRB 990712
  82. GRB 000214 near-IR observations
  83. GRB 000115 Optical observations
  84. GRB 000214, Radio Observations
  85. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  86. GRB000210, Radio Observations
  87. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  88. GRB 000115, BVRI field photometry
  89. GRB000214: BeppoSAX GRBM and WFC Detection
  90. IPN annulus for GRB000214
  91. Optical observations of GRB000210
  92. GRB000210 X-ray afterglow
  93. GRB000214: X-ray afterglow candidate
  94. GRB000214 refined BeppoSAX-WFC position
  95. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  96. GRB 000210: BATSE Observations
  97. Correction to Chandra Position of GRB000210 afterglow
  98. Optical observations of the Chandra X-ray source for GRB000210
  99. GRB000210, Radio Observations
  100. Optical candidate for GRB000210

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