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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"

42588 results found.

  1. GRB 000307 optical observations
  2. GRB000323 [IPN Position]
  3. Single error box for GRB000315
  4. GRB000315 [IPN Positions]
  5. GRB000313, Radio observations
  6. GRB 000313 - optical transient in the BATSE error box
  7. GRB000301C - B and R photometry
  8. GRB000301C - R photometry
  9. GRB 000307, Optical Observations
  10. GRB 000307, BVRI Field Photometry
  11. GRB 000301C: Optical Spectrum and Redshift
  12. GRB 000301C: Optical Spectrum and Redshift
  13. GRB 000301C: A Precise Redshift Determination
  14. GRB 000301C, Optical Observation
  15. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  16. GRB 000301C: HST/STIS CCD Imaging of the field
  17. IPN error box for GRB000307
  18. GRB 000301c: K' observations
  19. GRB000301C, optical R-band observations
  20. GRB000301c - R photometry and nearby faint source confirmation
  21. GRB 000301C, Optical Observation
  22. GRB 000301c: K' observations
  23. GRB 000301C Optical Observations
  24. GRB 000301C: K' Observations
  25. GRB000301C OT candidate optical observations
  26. GRB000301C - Host galaxy not detected in R (?)
  27. Optical observations of GRB000301c
  28. GRB000301C, Radio observations
  29. GRB000301C, Radio observations
  30. GRB000301C optical observations
  31. GRB000301C, near-infrared observations (JHK' imaging)
  32. GRB 000301c near-IR observations
  33. GRB 000301C, Optical Color
  34. GRB000301C, Optical Spectroscopy
  35. GRB 000301C, UBVRI field photometry
  36. GRB 000301C, Optical Observation
  37. GRB000301C, optical observations
  38. GRB000301C 250 GHz detection
  39. GRB 000301C R-band observation
  40. GRB 000301C, Optical Observation
  41. GRB000301C, near-infrared observations (JHK' photometry)
  42. GRB 000301C: OT confirmed
  43. GRB000301c optical observations
  44. GRB 000301A, Radio Observations
  45. GRB000301C, optical observations
  46. GRB000301c, near-infrared observations
  47. GRB000301C
  48. GRB 000301C : Optical Candidate
  49. Radio observations of the error box of GRB000301A
  50. GRB000301C: RXTE/ASM and IPN localizations
  51. GRB000226 [IPN Position]
  52. HST Observations of GRB 990712
  53. GRB 000214 near-IR observations
  54. GRB 000115 Optical observations
  55. GRB 000214, Radio Observations
  56. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  57. GRB000210, Radio Observations
  58. GRB 000115, BVRI field photometry
  59. GRB000214: BeppoSAX GRBM and WFC Detection
  60. IPN annulus for GRB000214
  61. Optical observations of GRB000210
  62. GRB000210 X-ray afterglow
  63. GRB000214: X-ray afterglow candidate
  64. GRB000214 refined BeppoSAX-WFC position
  65. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  66. GRB 000210: BATSE Observations
  67. Correction to Chandra Position of GRB000210 afterglow
  68. Optical observations of the Chandra X-ray source for GRB000210
  69. GRB000210, Radio Observations
  70. Optical candidate for GRB000210
  71. Chandra Observations of GRB000210 X-ray Afterglow
  72. IPN triangulation of GRB000210
  73. GRB000210: possible afterglow detection with BeppoSAX NFI
  74. GRB000201, Radio Observations
  75. GRB000210: BeppoSAX GRBM and WFC Detection
  76. Optical observations of GRB000131
  77. GRB000201 Optical Observations
  78. GRB 000201: TAROT optical observations
  79. GRB 000131 Optical Observations
  80. GRB000126 Optical Observations
  81. BATSE GRB trigger criteria changed
  82. GRB 991208, radio observations
  83. BATSE+IPN location of GRB000131
  84. IPN localization of GRB000131
  85. GRB000126, optical observations
  86. BATSE location of GRB000126
  87. IPN localization of GRB000126
  88. GRB 000115 Optical observations
  89. BATSE Observations of GRB000115
  90. Correction to GCN 520 (IPN annulus for GRB000115)
  91. IPN annulus for GRB000115
  92. Second RXTE Observation of GRB 000115
  93. GRB991216, UBVRIJHK field photometry
  94. GRB991216 late optical observation
  95. GCN resumes full operations
  96. GRB 991216 VLBA Observations
  97. BEPPOSAX GRBM Localization of GRB991226
  98. IPN error boxes for GRB991229
  99. GRB 991216: J band spectrophotometry
  100. GRB 991216: Detection of the Host and/or Absorber Galaxy

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