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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"

24659 results found.

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

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