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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"

2798 results found.

  1. GRB000615, further R-band photometry
  2. BeppoSAX X-ray transient/possible GRB000608
  3. GRB 000418: Detection of the Host Galaxy
  4. IPN localization and time history of GRB000528
  5. New IPN localization of GRB000529
  6. GRB000508B, optical photometry
  7. Possible GRB-related phenomenon
  8. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  9. Refined IPN error box for GRB000408
  10. GRB000408 [IPN Position]
  11. GRB000315 [IPN Positions]
  12. GRB 000301C: Optical Spectrum and Redshift
  13. GRB 000301C: Optical Spectrum and Redshift
  14. GRB 000301C: A Precise Redshift Determination
  15. IPN error box for GRB000307
  16. GRB000301C - Host galaxy not detected in R (?)
  17. GRB000301C, near-infrared observations (JHK' imaging)
  18. GRB000301C, optical observations
  19. GRB000301C, near-infrared observations (JHK' photometry)
  20. GRB 000301A, Radio Observations
  21. GRB000226 [IPN Position]
  22. IPN annulus for GRB000214
  23. Correction to Chandra Position of GRB000210 afterglow
  24. GRB000210: possible afterglow detection with BeppoSAX NFI
  25. BATSE+IPN location of GRB000131
  26. BATSE location of GRB000126
  27. IPN localization of GRB000126
  28. GRB991216 late optical observation
  29. BEPPOSAX GRBM Localization of GRB991226
  30. IPN error boxes for GRB991229
  31. IPN localization of GRB991226
  32. IPN error boxes for GRB991221
  33. IPN error box for GRB991216
  34. GRB991216 Optical and IR observations
  35. GRB 991216 Optical Observations
  36. GRB 991216, optical observations
  37. GRB991208, optical observations
  38. GRB 991106 Optical Observations
  39. GRB 991014, Optical Observations
  40. GRB990907 and 990908
  41. GRB 990806, Optical Observations
  42. GRB990806: possible X-ray afterglow, BeppoSAX
  43. GRB990705: No Evidence for Neutrino Signal
  44. BeppoSAX GRB990705: possible X-ray afterglow
  45. GRB 990704, optical observations
  46. GRB990704
  47. GRB990704
  48. GRB990704: possible X-ray afterglow
  49. Identification of a possible optical counterpart for GRB990704
  50. GRB 990510 optical observations
  51. GRB990510: NFI X-ray source
  52. GRB 990510 optical observations
  53. Refined IPN error box for GRB990506
  54. GRB 990506: Limits on the possible optical transient
  55. GRB 990506, armchair astronomy
  56. GRB 970228: Redshift and properties of the host galaxy
  57. GRB981220 VLBA observations
  58. GRB990321 REFINED IPN ANNULUS
  59. GRB990321 IPN TRIANGULATION
  60. GRB 990316 Optical Observations
  61. GRB990316: simultaneous optical observation
  62. ASM/IPN error box for GRB 990308 (BATSE #7457)
  63. GRB990308, Possible new SGR~0209+70
  64. GRB981220, IPN localization
  65. GRB 981220, radio observations
  66. GRB 990123: Updated Keck Spectroscopy Results
  67. GRB990123, Optical observation
  68. GRB 990123: New Constraints on Possible Foreground Galaxies
  69. Search for Potential Images of GRB 990123
  70. Search for Potential Images of GRB 990123
  71. GRB990123 IPN annulus
  72. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  73. GRB 990123 Spectroscopic Redshifts
  74. GRB 990123: Possible Gravitationally Lensed Burst?
  75. GRB 990123 optical observations
  76. GRB 990123: Bright New Source, Possible Optical Transient
  77. Possible identification of SN1999E with GRB980910
  78. GRB981220
  79. GRB 981226 optical observations
  80. GRB 981220
  81. GRB980703: Radio transient
  82. SGR1627-41, Refined IPN annulus location
  83. Reduced error box of SGR 1627-41
  84. SGR 1627-41
  85. SGR1900+14
  86. SGR1900+14
  87. GRB980519 optical observations
  88. GRB980519 Optical Observations
  89. GRB 980425 Brightness Temperature
  90. GRB980329 infrared observations
  91. Optical Observations of the GRB 971227 field
  92. GRB971227: Plaskett R-band observations
  93. GRB 971227: Optical clarifications
  94. GRB 971214: Redshift from Keck Optical Observations
  95. GRB 971214: USNOFS Observations Summary
  96. IRAS 18119-1342 and the possible new SGR
  97. Possible new SGR from US Naval Observatory
  98. GRB 970828: Palomar Observations

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