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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"

36140 results found.

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

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