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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"

25045 results found.

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

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