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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"

32423 results found.

  1. GRB 000418, optical observation
  2. GRB000424 Optical Observations
  3. GRB 000418, Optical Observation
  4. GRB 000424, Optical Observations
  5. GRB 000418, Optical Observation
  6. GRB000418, near-infrared observations
  7. Correction to IPN error box for GRB000419
  8. IPN error box for GRB000418
  9. GRB000419 [IPN Position]
  10. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  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. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  18. GRB000408 [IPN Position]
  19. GRB000326 Optical Observations
  20. GRB000301C - Addendum to GCN 623
  21. GRB000301C - R magnitude lower limit
  22. GRB 000323, optical observations
  23. GRB 000326: Optical Observations
  24. GRB000326, Radio observations
  25. GRB000326 [IPN Position]
  26. GRB 000307 optical observations
  27. GRB000323 [IPN Position]
  28. GRB000315 [IPN Positions]
  29. GRB 000313 - optical transient in the BATSE error box
  30. GRB000301C - B and R photometry
  31. GRB000301C - R photometry
  32. GRB 000307, Optical Observations
  33. GRB 000307, BVRI Field Photometry
  34. GRB 000301C: Optical Spectrum and Redshift
  35. GRB 000301C: Optical Spectrum and Redshift
  36. GRB 000301C: A Precise Redshift Determination
  37. GRB 000301C, Optical Observation
  38. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  39. GRB 000301C: HST/STIS CCD Imaging of the field
  40. IPN error box for GRB000307
  41. GRB 000301c: K' observations
  42. GRB000301C, optical R-band observations
  43. GRB000301c - R photometry and nearby faint source confirmation
  44. GRB 000301C, Optical Observation
  45. GRB 000301c: K' observations
  46. GRB 000301C Optical Observations
  47. GRB 000301C: K' Observations
  48. GRB000301C - Host galaxy not detected in R (?)
  49. GRB000301C optical observations
  50. GRB 000301c near-IR observations
  51. GRB 000301C, Optical Color
  52. GRB000301C, Optical Spectroscopy
  53. GRB 000301C, UBVRI field photometry
  54. GRB 000301C, Optical Observation
  55. GRB000301C 250 GHz detection
  56. GRB 000301C R-band observation
  57. GRB 000301C, Optical Observation
  58. GRB000301C, near-infrared observations (JHK' photometry)
  59. GRB 000301C: OT confirmed
  60. GRB000301c optical observations
  61. GRB 000301A, Radio Observations
  62. GRB000301C, optical observations
  63. GRB000301c, near-infrared observations
  64. GRB000301C
  65. GRB 000301C : Optical Candidate
  66. GRB000301C: RXTE/ASM and IPN localizations
  67. GRB000226 [IPN Position]
  68. HST Observations of GRB 990712
  69. GRB 000214 near-IR observations
  70. GRB 000115 Optical observations
  71. GRB 000214, Radio Observations
  72. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  73. GRB 000115, BVRI field photometry
  74. IPN annulus for GRB000214
  75. BATSE GRB trigger criterion changed
  76. GRB000210 X-ray afterglow
  77. GRB000214: X-ray afterglow candidate
  78. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  79. GRB 000210: BATSE Observations
  80. Optical observations of the Chandra X-ray source for GRB000210
  81. Chandra Observations of GRB000210 X-ray Afterglow
  82. IPN triangulation of GRB000210
  83. GRB 000201: TAROT optical observations
  84. GRB 000131 Optical Observations
  85. GRB000126 Optical Observations
  86. BATSE GRB trigger criteria changed
  87. GRB 991208, radio observations
  88. BATSE+IPN location of GRB000131
  89. IPN localization of GRB000131
  90. GRB 000126, optical observations
  91. GRB000126, optical observations
  92. BATSE location of GRB000126
  93. IPN localization of GRB000126
  94. GRB 000115 Optical observations
  95. BATSE Observations of GRB000115
  96. Second RXTE Observation of GRB 000115
  97. GRB991216, UBVRIJHK field photometry
  98. Single IPN error box for GRB991229
  99. GRB 991216 VLBA Observations
  100. BEPPOSAX GRBM Localization of GRB991226

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