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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"

21206 results found.

  1. Possible GRB-related phenomenon
  2. RXTE/ASM and IPN localization of GRB 000508B
  3. GRB000424, UBVRI field photometry
  4. GRB000418, UBVRI field photometry update
  5. The redshift of GRB 000418
  6. GRB000424, optical observations
  7. GRB 000429, optical observation
  8. GRB 000429, UBVRI field photometry
  9. GRB 000418, UBVRI field photometry
  10. GRB 000418, optical observation
  11. GRB000424 Optical Observations
  12. GRB 000418, Optical Observation
  13. Correction to IPN error box for GRB000419
  14. IPN error box for GRB000418
  15. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  16. GRB 000408, optical observations
  17. GRB 991208, UBVRI field photometry
  18. GRB000408, lotis optical observations
  19. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  20. GRB000408 [IPN Position]
  21. GRB000301C - Addendum to GCN 623
  22. GRB 000326: Optical Observations
  23. GRB000326, Radio observations
  24. GRB000315 [IPN Positions]
  25. GRB000313, Radio observations
  26. GRB 000313 - optical transient in the BATSE error box
  27. GRB 000307, BVRI Field Photometry
  28. GRB 000301C: HST/STIS CCD Imaging of the field
  29. IPN error box for GRB000307
  30. GRB000301C, optical R-band observations
  31. GRB000301c - R photometry and nearby faint source confirmation
  32. GRB 000301C Optical Observations
  33. GRB 000301C: K' Observations
  34. GRB000301C - Host galaxy not detected in R (?)
  35. Optical observations of GRB000301c
  36. GRB000301C, Radio observations
  37. GRB000301C, Radio observations
  38. GRB 000301c near-IR observations
  39. GRB 000301C, UBVRI field photometry
  40. GRB000301C, near-infrared observations (JHK' photometry)
  41. GRB 000301C: OT confirmed
  42. GRB000301c optical observations
  43. GRB000301c, near-infrared observations
  44. GRB000301C
  45. GRB 000301C : Optical Candidate
  46. GRB000301C: RXTE/ASM and IPN localizations
  47. GRB000226 [IPN Position]
  48. HST Observations of GRB 990712
  49. GRB 000214 near-IR observations
  50. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  51. GRB000210, Radio Observations
  52. GRB 000115, BVRI field photometry
  53. GRB000214: BeppoSAX GRBM and WFC Detection
  54. Optical observations of GRB000210
  55. GRB000210 X-ray afterglow
  56. GRB000214: X-ray afterglow candidate
  57. GRB000214 refined BeppoSAX-WFC position
  58. GRB 000210: BATSE Observations
  59. Optical observations of the Chandra X-ray source for GRB000210
  60. GRB000210, Radio Observations
  61. GRB000201, Radio Observations
  62. GRB000210: BeppoSAX GRBM and WFC Detection
  63. Optical observations of GRB000131
  64. GRB000201 Optical Observations
  65. GRB 000201: TAROT optical observations
  66. IPN localization of GRB000131
  67. GRB 000126, optical observations
  68. IPN localization of GRB000126
  69. BATSE Observations of GRB000115
  70. GRB991216, UBVRIJHK field photometry
  71. GCN resumes full operations
  72. IPN error boxes for GRB991229
  73. GRB 991216: Detection of the Host and/or Absorber Galaxy
  74. IPN error boxes for GRB991221
  75. IPN error box for GRB991216
  76. GRB 991217 (SAX J2303.2+0015) Optical observations
  77. Chandra observation of the X-ray afterglow of GRB991216
  78. GRB 991216, optical observations
  79. GRB 991216 Optical spectroscopy/imaging
  80. GRB991216 Optical and IR observations
  81. SAX J2303.2+0015 Optical observations
  82. IR observations of GRB991216
  83. GRB 991217 (SAX J2303.2+0015) Optical observations
  84. GRB991216 Optical and infrared observations of Beethoven Burst
  85. GRB 991216 Radio Observations
  86. GRB 991208 Infrared Detection
  87. GRB991216
  88. GRB 991216--Summary of RXTE Observations
  89. GRB 991216 Optical Observations
  90. GRB 991216, optical observations
  91. GRB 991208 SAO-RAS Spectroscopy
  92. SAX J2303.2+0015: an x-ray/GRB?
  93. GRB 991216, Optical Transient
  94. GRB991216 ('Beethoven Burst') B, R, and K Observations
  95. GRB991216, infrared observations
  96. GRB 991208 optical observations
  97. Lowell/Perkins observation of GRB 991216
  98. GRB 991216 Optical Observation
  99. GRB 991216: Extremely bright BATSE burst
  100. R-band Observations of GRB991208 at TNG

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