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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"

24943 results found.

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

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