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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"

24663 results found.

  1. GRB000528, optical observations at ESO
  2. GRB 000604 optical observations
  3. GRB 000418: Detection of the Host Galaxy
  4. GRB000604, optical observations, comparison with DPOSS
  5. GRB000528, Radio Observations
  6. X-ray Afterglow of GRB 000529
  7. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  8. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  9. GRB 000528 - WFC measurements
  10. GRB000519, BVRI field photometry
  11. IPN triangulation of GRB000519
  12. GRB000508B, optical photometry
  13. GRB000508B, BVR field photometry
  14. Possible GRB-related phenomenon
  15. RXTE/ASM and IPN localization of GRB 000508B
  16. GRB000424, UBVRI field photometry
  17. GRB000418, UBVRI field photometry update
  18. GRB000424, optical observations
  19. GRB 000429, optical observation
  20. GRB 000429, UBVRI field photometry
  21. GRB 000418, UBVRI field photometry
  22. GRB 000418, optical observation
  23. GRB 000418, Optical Observation
  24. GRB000418, near-infrared observations
  25. Correction to IPN error box for GRB000419
  26. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  27. GRB000416 BRJK observations
  28. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  29. GRB 000408, optical observations
  30. GRB 991208, UBVRI field photometry
  31. GRB000408, lotis optical observations
  32. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  33. GRB000301C - Addendum to GCN 623
  34. GRB 000323, optical observations
  35. GRB 000326: Optical Observations
  36. GRB000326, Radio observations
  37. GRB000313, Radio observations
  38. GRB 000313 - optical transient in the BATSE error box
  39. GRB 000307, Optical Observations
  40. GRB 000307, BVRI Field Photometry
  41. GRB 000301C: A Precise Redshift Determination
  42. GRB 000301C, Optical Observation
  43. GRB 000301C: HST/STIS CCD Imaging of the field
  44. IPN error box for GRB000307
  45. GRB000301C, optical R-band observations
  46. GRB 000301C Optical Observations
  47. GRB 000301C: K' Observations
  48. GRB000301C OT candidate optical observations
  49. GRB000301C - Host galaxy not detected in R (?)
  50. Optical observations of GRB000301c
  51. GRB000301C, Radio observations
  52. GRB000301C, Radio observations
  53. GRB000301C, near-infrared observations (JHK' imaging)
  54. GRB 000301c near-IR observations
  55. GRB 000301C, UBVRI field photometry
  56. GRB 000301C: OT confirmed
  57. GRB000301c optical observations
  58. GRB000301C, optical observations
  59. GRB000301C
  60. GRB 000301C : Optical Candidate
  61. GRB000301C: RXTE/ASM and IPN localizations
  62. GRB000226 [IPN Position]
  63. HST Observations of GRB 990712
  64. GRB 000214 near-IR observations
  65. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  66. GRB000210, Radio Observations
  67. GRB 000115, BVRI field photometry
  68. GRB000214: BeppoSAX GRBM and WFC Detection
  69. Optical observations of GRB000210
  70. GRB000210 X-ray afterglow
  71. GRB000214: X-ray afterglow candidate
  72. GRB000214 refined BeppoSAX-WFC position
  73. GRB 000210: BATSE Observations
  74. Optical observations of the Chandra X-ray source for GRB000210
  75. GRB000210, Radio Observations
  76. IPN triangulation of GRB000210
  77. GRB000210: possible afterglow detection with BeppoSAX NFI
  78. GRB000201, Radio Observations
  79. GRB000210: BeppoSAX GRBM and WFC Detection
  80. SAX_WFC_GRB_NOTICE
  81. SAX_WFC_GRB_NOTICE
  82. GRB000201 Optical Observations
  83. GRB 000201: TAROT optical observations
  84. GRB 991208, radio observations
  85. BATSE+IPN location of GRB000131
  86. IPN localization of GRB000131
  87. GRB 000126, optical observations
  88. BATSE Observations of GRB000115
  89. Second RXTE Observation of GRB 000115
  90. GRB991216, UBVRIJHK field photometry
  91. GCN resumes full operations
  92. GRB 991216 VLBA Observations
  93. GRB 991216: J band spectrophotometry
  94. GRB 991216: Detection of the Host and/or Absorber Galaxy
  95. IPN localization of GRB991226
  96. GRB 991216 RXTE ASM Observations
  97. GRB 991216: Updated BATSE parameters
  98. GRB 991217 (SAX J2303.2+0015) Optical observations
  99. Chandra observation of the X-ray afterglow of GRB991216
  100. GRB 991216, optical observations

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