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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"

26068 results found.

  1. GRB000528: follow-up X-ray measurements and update of IPN annulus
  2. GRB980519, HST/STIS observations of the host galaxy
  3. GRB000604 optical non-detection
  4. GRB000604 - Optical observations
  5. GRB000604, optical observations
  6. GRB000528, optical observations at ESO
  7. GRB 000604 optical observations
  8. GRB 000418: Detection of the Host Galaxy
  9. GRB000604, optical observations, comparison with DPOSS
  10. GRB000528, Radio Observations
  11. X-ray Afterglow of GRB 000529
  12. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  13. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  14. GRB 000528 - WFC measurements
  15. GRB000519, BVRI field photometry
  16. IPN triangulation of GRB000519
  17. GRB000508B, optical photometry
  18. GRB000508B, BVR field photometry
  19. Possible GRB-related phenomenon
  20. RXTE/ASM and IPN localization of GRB 000508B
  21. GRB000424, UBVRI field photometry
  22. GRB000418, UBVRI field photometry update
  23. GRB000424, optical observations
  24. GRB 000429, optical observation
  25. GRB 000429, UBVRI field photometry
  26. GRB 000418, UBVRI field photometry
  27. GRB 000418, optical observation
  28. GRB 000418, Optical Observation
  29. GRB000418, near-infrared observations
  30. Correction to IPN error box for GRB000419
  31. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  32. GRB000416 BRJK observations
  33. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  34. GRB 000408, optical observations
  35. GRB 991208, UBVRI field photometry
  36. GRB000408, lotis optical observations
  37. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  38. GRB000301C - Addendum to GCN 623
  39. GRB 000323, optical observations
  40. GRB 000326: Optical Observations
  41. GRB000326, Radio observations
  42. GRB000313, Radio observations
  43. GRB 000313 - optical transient in the BATSE error box
  44. GRB 000307, Optical Observations
  45. GRB 000307, BVRI Field Photometry
  46. GRB 000301C: A Precise Redshift Determination
  47. GRB 000301C, Optical Observation
  48. GRB 000301C: HST/STIS CCD Imaging of the field
  49. IPN error box for GRB000307
  50. GRB000301C, optical R-band observations
  51. GRB 000301C Optical Observations
  52. GRB 000301C: K' Observations
  53. GRB000301C OT candidate optical observations
  54. GRB000301C - Host galaxy not detected in R (?)
  55. Optical observations of GRB000301c
  56. GRB000301C, Radio observations
  57. GRB000301C, Radio observations
  58. GRB000301C, near-infrared observations (JHK' imaging)
  59. GRB 000301c near-IR observations
  60. GRB 000301C, UBVRI field photometry
  61. GRB 000301C: OT confirmed
  62. GRB000301c optical observations
  63. GRB000301C, optical 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 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  71. GRB000210, Radio Observations
  72. GRB 000115, BVRI field photometry
  73. GRB000214: BeppoSAX GRBM and WFC Detection
  74. Optical observations of GRB000210
  75. GRB000210 X-ray afterglow
  76. GRB000214: X-ray afterglow candidate
  77. GRB000214 refined BeppoSAX-WFC position
  78. GRB 000210: BATSE Observations
  79. Optical observations of the Chandra X-ray source for GRB000210
  80. GRB000210, Radio Observations
  81. IPN triangulation of GRB000210
  82. GRB000210: possible afterglow detection with BeppoSAX NFI
  83. GRB000201, Radio Observations
  84. GRB000210: BeppoSAX GRBM and WFC Detection
  85. SAX_WFC_GRB_NOTICE
  86. SAX_WFC_GRB_NOTICE
  87. GRB000201 Optical Observations
  88. GRB 000201: TAROT optical observations
  89. GRB 991208, radio observations
  90. BATSE+IPN location of GRB000131
  91. IPN localization of GRB000131
  92. GRB 000126, optical observations
  93. BATSE Observations of GRB000115
  94. Second RXTE Observation of GRB 000115
  95. GRB991216, UBVRIJHK field photometry
  96. GCN resumes full operations
  97. GRB 991216 VLBA Observations
  98. GRB 991216: J band spectrophotometry
  99. GRB 991216: Detection of the Host and/or Absorber Galaxy
  100. IPN localization of GRB991226

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