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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"

19804 results found.

  1. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  2. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  3. Budget cuts in BeppoSAX operations: impact on GRB observations
  4. GRB 000408, optical observations
  5. GRB 991208, UBVRI field photometry
  6. GRB000301c results
  7. GRB000408, lotis optical observations
  8. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  9. GRB000301C - Addendum to GCN 623
  10. GRB 000326: Optical Observations
  11. GRB000326, Radio observations
  12. GRB000326 [IPN Position]
  13. GRB000313, Radio observations
  14. GRB 000313 - optical transient in the BATSE error box
  15. GRB000301C - R photometry
  16. GRB 000307, Optical Observations
  17. GRB 000307, BVRI Field Photometry
  18. GRB 000301C: Optical Spectrum and Redshift
  19. GRB 000301C: Optical Spectrum and Redshift
  20. GRB 000301C: A Precise Redshift Determination
  21. GRB 000301C, Optical Observation
  22. GRB 000301C: HST/STIS CCD Imaging of the field
  23. GRB000301C, optical R-band observations
  24. GRB 000301C Optical Observations
  25. GRB 000301C: K' Observations
  26. GRB000301C OT candidate optical observations
  27. GRB000301C - Host galaxy not detected in R (?)
  28. Optical observations of GRB000301c
  29. GRB000301C, Radio observations
  30. GRB000301C, Radio observations
  31. GRB 000301c near-IR observations
  32. GRB 000301C, UBVRI field photometry
  33. GRB000301C 250 GHz detection
  34. GRB 000301C R-band observation
  35. GRB000301C, near-infrared observations (JHK' photometry)
  36. GRB 000301C: OT confirmed
  37. GRB000301c optical observations
  38. GRB000301C, optical observations
  39. GRB000301c, near-infrared observations
  40. GRB000301C
  41. GRB 000301C : Optical Candidate
  42. GRB000226 [IPN Position]
  43. HST Observations of GRB 990712
  44. GRB 000214 near-IR observations
  45. GRB 000214, Radio Observations
  46. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  47. GRB000210, Radio Observations
  48. GRB 000115, BVRI field photometry
  49. GRB000214: BeppoSAX GRBM and WFC Detection
  50. BATSE GRB trigger criterion changed
  51. Optical observations of GRB000210
  52. GRB000210 X-ray afterglow
  53. GRB000214: X-ray afterglow candidate
  54. GRB000214 refined BeppoSAX-WFC position
  55. Optical observations of the Chandra X-ray source for GRB000210
  56. GRB000210, Radio Observations
  57. GRB000201, Radio Observations
  58. GRB000210: BeppoSAX GRBM and WFC Detection
  59. GRB000201 Optical Observations
  60. GRB 000131 Optical Observations
  61. GRB000126 Optical Observations
  62. BATSE GRB trigger criteria changed
  63. BATSE+IPN location of GRB000131
  64. IPN localization of GRB000131
  65. GRB 000126, optical observations
  66. GRB991216, UBVRIJHK field photometry
  67. GCN resumes full operations
  68. IPN error boxes for GRB991229
  69. GRB 991216: J band spectrophotometry
  70. GRB 991216: Detection of the Host and/or Absorber Galaxy
  71. GRB 991216 RXTE ASM Observations
  72. GRB 991216: Updated BATSE parameters
  73. GRB 991217 (SAX J2303.2+0015) Optical observations
  74. Chandra observation of the X-ray afterglow of GRB991216
  75. SAX J2303.2+0015 Optical observations
  76. IR observations of GRB991216
  77. GRB 991217 (SAX J2303.2+0015) Optical observations
  78. GRB 991216 Radio Observations
  79. GRB 991208 Keck Spectroscopy
  80. GRB 991208 Infrared Detection
  81. GRB991216
  82. GRB 991216--Summary of RXTE Observations
  83. GRB 991216 Optical Observations
  84. GRB 991216, optical observations
  85. GRB 991208 SAO-RAS Spectroscopy
  86. SAX J2303.2+0015: an x-ray/GRB?
  87. GRB 991216, Optical Transient
  88. GRB991216 ('Beethoven Burst') B, R, and K Observations
  89. GRB991216, infrared observations
  90. GRB 991208 optical observations
  91. GRB 991216 Optical Observation
  92. GRB 991208 Keck Spectroscopy
  93. GRB 991216: Extremely bright BATSE burst
  94. GRB991208, optical observations
  95. GRB 991208, Optical Observation
  96. GRB991208, optical observations
  97. GRB 991208 Optical Decay
  98. IPN localization of GRB991208
  99. Optical Observations of GRB991105
  100. GRB991106: BeppoSAX/BATSE results

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