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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"

17213 results found.

  1. GRB000630, optical observations
  2. GRB000630: Optical observations
  3. possible optical counterpart of GRB 000630
  4. IPN triangulation of GRB000630
  5. GRB 000620, optical observations
  6. GRB000418, HST/STIS Observations
  7. GRB990123: Late-time HST/STIS observations of the host
  8. GRB000620, optical observations
  9. GRB000620 - Optical observations
  10. GRB000620 Optical observations
  11. GRB000620: BeppoSAX WFC and GRBM detection
  12. GRB000607, optical observations
  13. GRB 000615: NIR further observations
  14. GRB000616 optical observations
  15. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  16. GRB000615, further R-band photometry
  17. GRB 000615: NIR observations
  18. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  19. GRB000615, R-band photometry
  20. GRB 000301C: Further Late-Time HST/STIS observations
  21. GRB000528: follow-up X-ray measurements and update of IPN annulus
  22. BeppoSAX X-ray transient/possible GRB000608
  23. GRB000604 - Optical observations
  24. GRB000607, A SHORT, HARD BURST
  25. GRB000604, optical observations
  26. GRB000528, optical observations at ESO
  27. GRB 000418: Detection of the Host Galaxy
  28. GRB000604, optical observations, comparison with DPOSS
  29. GRB000528, Radio Observations
  30. X-ray Afterglow of GRB 000529
  31. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  32. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  33. GRB 000528 - WFC measurements
  34. GRB000519, BVRI field photometry
  35. GRB000508B, optical photometry
  36. GRB000508B, BVR field photometry
  37. Possible GRB-related phenomenon
  38. RXTE/ASM and IPN localization of GRB 000508B
  39. GRB000424, UBVRI field photometry
  40. GRB000418, UBVRI field photometry update
  41. GRB000424, optical observations
  42. GRB 000429, optical observation
  43. GRB 000429, UBVRI field photometry
  44. GRB 000418, UBVRI field photometry
  45. GRB 000418, optical observation
  46. GRB 000418, Optical Observation
  47. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  48. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  49. Budget cuts in BeppoSAX operations: impact on GRB observations
  50. GRB 000408, optical observations
  51. Refined IPN error box for GRB000408
  52. GRB 991208, UBVRI field photometry
  53. GRB000408, lotis optical observations
  54. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  55. GRB000326 Optical Observations
  56. GRB000301C - Addendum to GCN 623
  57. GRB 000326: Optical Observations
  58. GRB000326, Radio observations
  59. GRB000326 [IPN Position]
  60. GRB000313, Radio observations
  61. GRB 000313 - optical transient in the BATSE error box
  62. GRB 000307, BVRI Field Photometry
  63. GRB 000301C: HST/STIS CCD Imaging of the field
  64. IPN error box for GRB000307
  65. GRB000301C, optical R-band observations
  66. GRB 000301C Optical Observations
  67. GRB 000301C: K' Observations
  68. GRB000301C - Host galaxy not detected in R (?)
  69. Optical observations of GRB000301c
  70. GRB000301C, Radio observations
  71. GRB000301C, Radio observations
  72. GRB 000301c near-IR observations
  73. GRB 000301C, UBVRI field photometry
  74. GRB000301C, near-infrared observations (JHK' photometry)
  75. GRB 000301C: OT confirmed
  76. GRB000301c optical observations
  77. GRB000301C
  78. GRB 000301C : Optical Candidate
  79. HST Observations of GRB 990712
  80. GRB 000214 near-IR observations
  81. GRB 000214, Radio Observations
  82. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  83. GRB000210, Radio Observations
  84. GRB 000115, BVRI field photometry
  85. GRB000214: BeppoSAX GRBM and WFC Detection
  86. Optical observations of GRB000210
  87. GRB000210 X-ray afterglow
  88. GRB000214: X-ray afterglow candidate
  89. GRB000214 refined BeppoSAX-WFC position
  90. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  91. Correction to Chandra Position of GRB000210 afterglow
  92. Optical observations of the Chandra X-ray source for GRB000210
  93. GRB000210, Radio Observations
  94. GRB000210: possible afterglow detection with BeppoSAX NFI
  95. GRB000201, Radio Observations
  96. GRB000210: BeppoSAX GRBM and WFC Detection
  97. GRB000201 Optical Observations
  98. GRB 000126, optical observations
  99. IPN localization of GRB000126
  100. IPN annulus for GRB000115

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