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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"

21650 results found.

  1. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  2. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  3. GRB000529: Optical Observations
  4. IPN localization and time history of GRB000528
  5. IPN localization of GRB000529
  6. GRB 000528 - WFC measurements
  7. GRB000519, BVRI field photometry
  8. IPN triangulation of GRB000519
  9. IPN triangulation of GRB000516
  10. Re: GRB000508B : Optical observations
  11. GRB000508B, optical photometry
  12. GRB000508B, BVR field photometry
  13. Possible GRB-related phenomenon
  14. RXTE/ASM and IPN localization of GRB 000508B
  15. GRB000424, UBVRI field photometry
  16. GRB 000424 Optical Observations
  17. GRB000418, UBVRI field photometry update
  18. GRB000424, optical observations
  19. GRB 000429, optical observation
  20. GRB 000429, UBVRI field photometry
  21. IPN localization of GRB000429
  22. GRB 000418, UBVRI field photometry
  23. GRB 000418, optical observation
  24. GRB000424, optical observations
  25. GRB 000418, Optical Observation
  26. IPN error box for GRB000418
  27. GRB000419 [IPN Position]
  28. GRB000416 Optical Observations
  29. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  30. Budget cuts in BeppoSAX operations: impact on GRB observations
  31. GRB 000408, optical observations
  32. GRB 991208, UBVRI field photometry
  33. GRB000408, lotis optical observations
  34. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  35. GRB000301C - Addendum to GCN 623
  36. GRB 000326: Optical Observations
  37. GRB000326, Radio observations
  38. GRB 000307 optical observations
  39. Single error box for GRB000315
  40. GRB000315 [IPN Positions]
  41. GRB000313, Radio observations
  42. GRB 000313 - optical transient in the BATSE error box
  43. GRB 000307, BVRI Field Photometry
  44. GRB 000301C: HST/STIS CCD Imaging of the field
  45. IPN error box for GRB000307
  46. GRB000301C, optical R-band observations
  47. GRB 000301C Optical Observations
  48. GRB 000301C: K' Observations
  49. GRB000301C OT candidate optical observations
  50. GRB000301C - Host galaxy not detected in R (?)
  51. Optical observations of GRB000301c
  52. GRB000301C, Radio observations
  53. GRB000301C, Radio observations
  54. GRB 000301c near-IR observations
  55. GRB 000301C, Optical Color
  56. GRB 000301C, UBVRI field photometry
  57. GRB000301C, near-infrared observations (JHK' photometry)
  58. GRB 000301C: OT confirmed
  59. GRB000301c optical observations
  60. GRB000301c, near-infrared observations
  61. GRB000301C
  62. GRB 000301C : Optical Candidate
  63. GRB000301C: RXTE/ASM and IPN localizations
  64. GRB000301A [IPN Position]
  65. GRB000226 [IPN Position]
  66. HST Observations of GRB 990712
  67. GRB 000214 near-IR observations
  68. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  69. GRB000210, Radio Observations
  70. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  71. GRB 000115, BVRI field photometry
  72. GRB000214: BeppoSAX GRBM and WFC Detection
  73. IPN annulus for GRB000214
  74. BATSE GRB trigger criterion changed
  75. Optical observations of GRB000210
  76. GRB000210 X-ray afterglow
  77. GRB000214: X-ray afterglow candidate
  78. GRB000214 refined BeppoSAX-WFC position
  79. GRB 000210: BATSE Observations
  80. Optical observations of the Chandra X-ray source for GRB000210
  81. GRB000210, Radio Observations
  82. GRB000201, Radio Observations
  83. GRB000210: BeppoSAX GRBM and WFC Detection
  84. GRB000201 Optical Observations
  85. BATSE+IPN location of GRB000131
  86. IPN localization of GRB000131
  87. GRB 000126, optical observations
  88. IPN annulus for GRB000115
  89. GRB991216, UBVRIJHK field photometry
  90. GCN resumes full operations
  91. GRB 991216: Detection of the Host and/or Absorber Galaxy
  92. IPN error box for GRB991216
  93. GRB 991216: Updated BATSE parameters
  94. GRB 991217 (SAX J2303.2+0015) Optical observations
  95. Chandra observation of the X-ray afterglow of GRB991216
  96. SAX J2303.2+0015 Optical observations
  97. IR observations of GRB991216
  98. GRB 991217 (SAX J2303.2+0015) Optical observations
  99. Refined IPN localization of GRB991216
  100. GRB 991216 Radio Observations

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