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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"

35335 results found.

  1. GRB000508B, optical photometry
  2. GRB000508B, BVR field photometry
  3. Possible GRB-related phenomenon
  4. RXTE/ASM and IPN localization of GRB 000508B
  5. GRB000424, UBVRI field photometry
  6. GRB 000424 Optical Observations
  7. GRB000418, UBVRI field photometry update
  8. The redshift of GRB 000418
  9. GRB 000429, optical observation
  10. GRB 000429, UBVRI field photometry
  11. IPN localization of GRB000429
  12. GRB 000418, UBVRI field photometry
  13. GRB000418, K'-band photometry
  14. GRB 000418, Optical Observation
  15. GRB 000418, optical observation
  16. GRB000424 Optical Observations
  17. GRB 000418, Optical Observation
  18. GRB 000424, Optical Observations
  19. GRB 000418, Optical Observation
  20. GRB000418, near-infrared observations
  21. Correction to IPN error box for GRB000419
  22. IPN error box for GRB000418
  23. GRB000419 [IPN Position]
  24. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  25. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  26. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  27. Budget cuts in BeppoSAX operations: impact on GRB observations
  28. GRB 000408, optical observations
  29. Refined IPN error box for GRB000408
  30. GRB 991208, UBVRI field photometry
  31. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  32. GRB000408 [IPN Position]
  33. GRB000326 Optical Observations
  34. GRB000301C - Addendum to GCN 623
  35. GRB000301C - R magnitude lower limit
  36. GRB 000323, optical observations
  37. GRB 000326: Optical Observations
  38. GRB000326, Radio observations
  39. GRB000326 [IPN Position]
  40. GRB 000307 optical observations
  41. GRB000323 [IPN Position]
  42. GRB000315 [IPN Positions]
  43. GRB 000313 - optical transient in the BATSE error box
  44. GRB000301C - B and R photometry
  45. GRB000301C - R photometry
  46. GRB 000307, Optical Observations
  47. GRB 000307, BVRI Field Photometry
  48. GRB 000301C: Optical Spectrum and Redshift
  49. GRB 000301C: Optical Spectrum and Redshift
  50. GRB 000301C: A Precise Redshift Determination
  51. GRB 000301C, Optical Observation
  52. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  53. GRB 000301C: HST/STIS CCD Imaging of the field
  54. IPN error box for GRB000307
  55. GRB 000301c: K' observations
  56. GRB000301C, optical R-band observations
  57. GRB000301c - R photometry and nearby faint source confirmation
  58. GRB 000301C, Optical Observation
  59. GRB 000301c: K' observations
  60. GRB 000301C Optical Observations
  61. GRB 000301C: K' Observations
  62. GRB000301C - Host galaxy not detected in R (?)
  63. GRB000301C optical observations
  64. GRB 000301c near-IR observations
  65. GRB 000301C, Optical Color
  66. GRB000301C, Optical Spectroscopy
  67. GRB 000301C, UBVRI field photometry
  68. GRB 000301C, Optical Observation
  69. GRB000301C 250 GHz detection
  70. GRB 000301C R-band observation
  71. GRB 000301C, Optical Observation
  72. GRB000301C, near-infrared observations (JHK' photometry)
  73. GRB 000301C: OT confirmed
  74. GRB000301c optical observations
  75. GRB 000301A, Radio Observations
  76. GRB000301C, optical observations
  77. GRB000301c, near-infrared observations
  78. GRB000301C
  79. GRB 000301C : Optical Candidate
  80. GRB000301C: RXTE/ASM and IPN localizations
  81. GRB000226 [IPN Position]
  82. HST Observations of GRB 990712
  83. GRB 000214 near-IR observations
  84. GRB 000115 Optical observations
  85. GRB 000214, Radio Observations
  86. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  87. GRB 000115, BVRI field photometry
  88. IPN annulus for GRB000214
  89. BATSE GRB trigger criterion changed
  90. GRB000210 X-ray afterglow
  91. GRB000214: X-ray afterglow candidate
  92. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  93. GRB 000210: BATSE Observations
  94. Optical observations of the Chandra X-ray source for GRB000210
  95. Chandra Observations of GRB000210 X-ray Afterglow
  96. IPN triangulation of GRB000210
  97. GRB 000201: TAROT optical observations
  98. GRB 000131 Optical Observations
  99. GRB000126 Optical Observations
  100. BATSE GRB trigger criteria changed

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