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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"

2797 results found.

  1. BeppoSAX X-ray transient/possible GRB000608
  2. GRB 000418: Detection of the Host Galaxy
  3. IPN localization and time history of GRB000528
  4. New IPN localization of GRB000529
  5. GRB000508B, optical photometry
  6. Possible GRB-related phenomenon
  7. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  8. Refined IPN error box for GRB000408
  9. GRB000408 [IPN Position]
  10. GRB000315 [IPN Positions]
  11. GRB 000301C: Optical Spectrum and Redshift
  12. GRB 000301C: Optical Spectrum and Redshift
  13. GRB 000301C: A Precise Redshift Determination
  14. IPN error box for GRB000307
  15. GRB000301C - Host galaxy not detected in R (?)
  16. GRB000301C, near-infrared observations (JHK' imaging)
  17. GRB000301C, optical observations
  18. GRB000301C, near-infrared observations (JHK' photometry)
  19. GRB 000301A, Radio Observations
  20. GRB000226 [IPN Position]
  21. IPN annulus for GRB000214
  22. Correction to Chandra Position of GRB000210 afterglow
  23. GRB000210: possible afterglow detection with BeppoSAX NFI
  24. BATSE+IPN location of GRB000131
  25. BATSE location of GRB000126
  26. IPN localization of GRB000126
  27. GRB991216 late optical observation
  28. BEPPOSAX GRBM Localization of GRB991226
  29. IPN error boxes for GRB991229
  30. IPN localization of GRB991226
  31. IPN error boxes for GRB991221
  32. IPN error box for GRB991216
  33. GRB991216 Optical and IR observations
  34. GRB 991216 Optical Observations
  35. GRB 991216, optical observations
  36. GRB991208, optical observations
  37. GRB 991106 Optical Observations
  38. GRB 991014, Optical Observations
  39. GRB990907 and 990908
  40. GRB 990806, Optical Observations
  41. GRB990806: possible X-ray afterglow, BeppoSAX
  42. GRB990705: No Evidence for Neutrino Signal
  43. BeppoSAX GRB990705: possible X-ray afterglow
  44. GRB 990704, optical observations
  45. GRB990704
  46. GRB990704
  47. GRB990704: possible X-ray afterglow
  48. Identification of a possible optical counterpart for GRB990704
  49. GRB 990510 optical observations
  50. GRB990510: NFI X-ray source
  51. GRB 990510 optical observations
  52. Refined IPN error box for GRB990506
  53. GRB 990506: Limits on the possible optical transient
  54. GRB 990506, armchair astronomy
  55. GRB 970228: Redshift and properties of the host galaxy
  56. GRB981220 VLBA observations
  57. GRB990321 REFINED IPN ANNULUS
  58. GRB990321 IPN TRIANGULATION
  59. GRB 990316 Optical Observations
  60. GRB990316: simultaneous optical observation
  61. ASM/IPN error box for GRB 990308 (BATSE #7457)
  62. GRB990308, Possible new SGR~0209+70
  63. GRB981220, IPN localization
  64. GRB 981220, radio observations
  65. GRB 990123: Updated Keck Spectroscopy Results
  66. GRB990123, Optical observation
  67. GRB 990123: New Constraints on Possible Foreground Galaxies
  68. Search for Potential Images of GRB 990123
  69. Search for Potential Images of GRB 990123
  70. GRB990123 IPN annulus
  71. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  72. GRB 990123 Spectroscopic Redshifts
  73. GRB 990123: Possible Gravitationally Lensed Burst?
  74. GRB 990123 optical observations
  75. GRB 990123: Bright New Source, Possible Optical Transient
  76. Possible identification of SN1999E with GRB980910
  77. GRB981220
  78. GRB 981226 optical observations
  79. GRB 981220
  80. GRB980703: Radio transient
  81. SGR1627-41, Refined IPN annulus location
  82. Reduced error box of SGR 1627-41
  83. SGR 1627-41
  84. SGR1900+14
  85. SGR1900+14
  86. GRB980519 optical observations
  87. GRB980519 Optical Observations
  88. GRB 980425 Brightness Temperature
  89. GRB980329 infrared observations
  90. Optical Observations of the GRB 971227 field
  91. GRB971227: Plaskett R-band observations
  92. GRB 971227: Optical clarifications
  93. GRB 971214: Redshift from Keck Optical Observations
  94. GRB 971214: USNOFS Observations Summary
  95. IRAS 18119-1342 and the possible new SGR
  96. Possible new SGR from US Naval Observatory
  97. GRB 970828: Palomar Observations

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