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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"

36134 results found.

  1. GRB 000424 Optical Observations
  2. GRB000418, UBVRI field photometry update
  3. The redshift of GRB 000418
  4. GRB 000429, optical observation
  5. GRB 000429, UBVRI field photometry
  6. IPN localization of GRB000429
  7. GRB 000418, UBVRI field photometry
  8. GRB000418, K'-band photometry
  9. GRB 000418, Optical Observation
  10. GRB 000418, optical observation
  11. GRB000424 Optical Observations
  12. GRB 000418, Optical Observation
  13. GRB 000424, Optical Observations
  14. GRB 000418, Optical Observation
  15. GRB000418, near-infrared observations
  16. Correction to IPN error box for GRB000419
  17. IPN error box for GRB000418
  18. GRB000419 [IPN Position]
  19. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  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. Refined IPN error box for GRB000408
  25. GRB 991208, UBVRI field photometry
  26. GRB000301c results
  27. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  28. GRB000408 [IPN Position]
  29. GRB000326 Optical Observations
  30. GRB000301C - Addendum to GCN 623
  31. GRB000301C - R magnitude lower limit
  32. GRB 000323, optical observations
  33. GRB 000326: Optical Observations
  34. GRB000326, Radio observations
  35. GRB000326 [IPN Position]
  36. GRB 000307 optical observations
  37. GRB000323 [IPN Position]
  38. GRB000315 [IPN Positions]
  39. GRB 000313 - optical transient in the BATSE error box
  40. GRB000301C - B and R photometry
  41. GRB000301C - R photometry
  42. GRB 000307, Optical Observations
  43. GRB 000307, BVRI Field Photometry
  44. GRB 000301C: Optical Spectrum and Redshift
  45. GRB 000301C: Optical Spectrum and Redshift
  46. GRB 000301C: A Precise Redshift Determination
  47. GRB 000301C, Optical Observation
  48. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  49. GRB 000301C: HST/STIS CCD Imaging of the field
  50. IPN error box for GRB000307
  51. GRB 000301c: K' observations
  52. GRB000301C, optical R-band observations
  53. GRB000301c - R photometry and nearby faint source confirmation
  54. GRB 000301C, Optical Observation
  55. GRB 000301c: K' observations
  56. GRB 000301C Optical Observations
  57. GRB 000301C: K' Observations
  58. GRB000301C - Host galaxy not detected in R (?)
  59. Optical observations of GRB000301c
  60. GRB000301C optical observations
  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 250 GHz detection
  67. GRB 000301C R-band observation
  68. GRB 000301C, Optical Observation
  69. GRB000301C, near-infrared observations (JHK' photometry)
  70. GRB 000301C: OT confirmed
  71. GRB000301c optical observations
  72. GRB 000301A, Radio Observations
  73. GRB000301C, optical observations
  74. GRB000301c, near-infrared observations
  75. GRB000301C
  76. GRB 000301C : Optical Candidate
  77. GRB000301C: RXTE/ASM and IPN localizations
  78. GRB000226 [IPN Position]
  79. HST Observations of GRB 990712
  80. GRB 000214 near-IR observations
  81. GRB 000115 Optical observations
  82. GRB 000214, Radio Observations
  83. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  84. GRB 000115, BVRI field photometry
  85. IPN annulus for GRB000214
  86. BATSE GRB trigger criterion changed
  87. GRB000210 X-ray afterglow
  88. GRB000214: X-ray afterglow candidate
  89. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  90. GRB 000210: BATSE Observations
  91. Optical observations of the Chandra X-ray source for GRB000210
  92. Chandra Observations of GRB000210 X-ray Afterglow
  93. IPN triangulation of GRB000210
  94. GRB 000201: TAROT optical observations
  95. GRB 000131 Optical Observations
  96. GRB000126 Optical Observations
  97. BATSE GRB trigger criteria changed
  98. GRB 991208, radio observations
  99. BATSE+IPN location of GRB000131
  100. IPN localization of GRB000131

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