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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"

30654 results found.

  1. GRB 990123 Optical Follow-Up
  2. GRB 990123; Addendum to GCN 223
  3. GRB 990123: BATSE Observations
  4. GRB 990123 Keck Spectrum update
  5. GRB990123 IPN annulus
  6. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  7. GRB990123 Optical Observations
  8. GRB 990123 Spectroscopic Redshifts
  9. GRB 990123: New Optical Observations, Decay Measure
  10. GRB 990123 Optical Follow-Up
  11. GRB 990123: Possible Gravitationally Lensed Burst?
  12. GRB990123, optical observation
  13. GRB 990123 optical observations
  14. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  15. GRB 990123 radio observations
  16. GRB 990123, new radio source
  17. GRB990123, Optical observation
  18. GRB 990123: Optical Decay Slope
  19. GRB 990123 r-band photometry
  20. GRB 990123 Optical Follow-up
  21. GRB990123, early optical counterpart detection
  22. GRB990123 Optical Observation
  23. GRB 990123: Bright New Source, Possible Optical Transient
  24. GRB 990123, Radio observations
  25. SN 1999E & GRB 980919
  26. Optical Observations of GRB 981220
  27. GRB 981226: radio variable
  28. GRB981220
  29. GRB981220, Correction to GCN 179
  30. GRB981220, Optical Observations
  31. GRB 981220 Optical observations
  32. GRB 981226 Optical Observations
  33. GRB 980613: Spectroscopy of the host galaxy
  34. GRB981226, sub-millimeter observations
  35. GRB981220, sub-millimeter observations
  36. GRB 981220 and GRB 981226, optical observations
  37. GRB981226 Optical Observations
  38. GRB 981226 radio observations
  39. GRB 981226
  40. radio observations of GRB 981226
  41. GRB981220 B, R and I band observations
  42. Optical Observations of GRB981226
  43. GRB 981220:Optical Observations
  44. GRB 981220 optical R and I observations
  45. GRB981226, BeppoSAX Christmas GRB
  46. GRB 981226 - Infrared Observations
  47. GRB 981220
  48. GRB 981220, radio observations
  49. GRB 981220, radio observations
  50. GRB 981220: BeppoSAX/GRBM results
  51. GRB981220 I-band Observations
  52. GRB 981220
  53. GRB 981220 Optical Observations
  54. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  55. BeppoSAX NFI Observation of GRB980425
  56. GRB980425 Optical Follow-up
  57. GRB980425: X-ray revised positions
  58. GRB980703 Very Long Baseline Interferometry
  59. GRB970508 optical observations
  60. Optical Observations of the Host Galaxy of GRB 980519
  61. GRB980519, Optical Observations
  62. GRB980703, Host galaxy multicolor photometry
  63. GRB 980703 (NFI observations)
  64. GRB980703 optical photometry
  65. GRB 980703: BATSE Observations
  66. GRB980703 optical observations
  67. GRB980703: Radio transient
  68. GRB980703 H-band Observations
  69. GRB 980703: Spectrum of the proposed optical counterpart
  70. RXTE Observation of GRB 980706
  71. GRB980703: Spectrum of the proposed optical counterpart
  72. GRB980703 Transient Optical Follow-Up
  73. GRB980703: LOTIS observation at early times
  74. GRB980613 Optical Observations
  75. GRB 980703
  76. GRB980703 (I band observations)
  77. GRB 980703 H-band Observations
  78. GRB980703: radio source/optical transient
  79. BeppoSAX NFI observations of GRB 980703
  80. GRB980519 observation report
  81. Radio observations of SGRs
  82. GRB 980613 Near-IR observations
  83. GRB980613, optical observations
  84. GRB 980613: Optical transient and its host galaxy
  85. SGR1627-41, RXTE/ASM observations
  86. SGR1627-41, Refined IPN annulus location
  87. GRB 980613: Detection of the probable host galaxy
  88. Reduced error box of SGR 1627-41
  89. SGR1627-41, BeppoSAX-GRBM detections
  90. GRB 980613 Optical Observations
  91. GRB 980613 optical observations
  92. GRB980613 Optical Observations
  93. GRB980613 observations from Palomar
  94. GRB 980613 new optical/IR observations
  95. GRB971214 Secondary Standards
  96. GRB980519 Secondary Standards
  97. SGR1900+14
  98. GRB 980519 Optical Observations
  99. GRB980519 optical observations
  100. GRB980519 I-band observations

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