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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"

22076 results found.

  1. GRB990123: NIR Observation
  2. "GRB 990123: New BV Observations"
  3. GRB 990123 Optical Follow-Up
  4. GRB 990123; Addendum to GCN 223
  5. GRB 990123: BATSE Observations
  6. GRB990123 Optical Observations
  7. GRB 990123 Spectroscopic Redshifts
  8. GRB 990123: New Optical Observations, Decay Measure
  9. GRB 990123: Possible Gravitationally Lensed Burst?
  10. GRB 990123 optical observations
  11. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  12. GRB 990123 radio observations
  13. GRB 990123, new radio source
  14. GRB990123 optical observations
  15. GRB 990123 Optical Follow-up
  16. GRB990123, early optical counterpart detection
  17. GRB 990123, Radio observations
  18. SN 1999E & GRB 980919
  19. Possible identification of SN1999E with GRB980910
  20. Optical Observations of GRB 981220
  21. GRB981220
  22. GRB981220, Correction to GCN 179
  23. GRB981220, Optical Observations
  24. GRB 981220 Optical observations
  25. GRB 981226 Optical Observations
  26. GRB 980613: Spectroscopy of the host galaxy
  27. GRB981226, sub-millimeter observations
  28. GRB981220, sub-millimeter observations
  29. GRB 981220 and GRB 981226, optical observations
  30. GRB981226 Optical Observations
  31. GRB 981226 radio observations
  32. GRB 981226
  33. GRB 981226 optical observations
  34. radio observations of GRB 981226
  35. GRB981220 B, R and I band observations
  36. Optical Observations of GRB981226
  37. GRB 981220:Optical Observations
  38. GRB 981220 optical R and I observations
  39. GRB981226, BeppoSAX Christmas GRB
  40. GRB 981226 - Infrared Observations
  41. GRB 981226 optical observations
  42. GRB 981220
  43. GRB 981220, radio observations
  44. GRB981226 Optical Observation
  45. GRB 981220, radio observations
  46. GRB981220 I-band Observations
  47. GRB981220 Optical Observations
  48. GRB 981220
  49. GRB 981220 Optical Observations
  50. GRB 981220, optical observations
  51. GRB 980326/Host Galaxy
  52. GRB980329 R,I flux calibration and R,I,K upper limits
  53. GRB980425 Optical Follow-up
  54. GRB980425: X-ray revised positions
  55. GRB 980923 BATSE Observations
  56. SGR1900+14, BeppoSAX-GRBM observations
  57. GRB980703 Very Long Baseline Interferometry
  58. GRB970508 optical observations
  59. Optical Observations of the Host Galaxy of GRB 980519
  60. GRB980519, Optical Observations
  61. GRB 980703 (NFI observations)
  62. GRB980703 optical photometry
  63. GRB 980703: BATSE Observations
  64. GRB980703 optical observations
  65. GRB980703 H-band Observations
  66. GRB 980703: Spectrum of the proposed optical counterpart
  67. GRB980703: Spectrum of the proposed optical counterpart
  68. GRB980613 Optical Observations
  69. GRB980703 (I band observations)
  70. GRB 980703 H-band Observations
  71. GRB980703 (optical R observations)
  72. GRB980703: radio source/optical transient
  73. BeppoSAX NFI observations of GRB 980703
  74. GRB980703 optical followup
  75. Radio observations of SGRs
  76. SGR1900+14 field optical observations
  77. GRB 980613 Near-IR observations
  78. GRB980613, optical observations
  79. SGR1627-41, RXTE/ASM observations
  80. GRB 980613: Detection of the probable host galaxy
  81. Reduced error box of SGR 1627-41
  82. GRB 980613: BATSE Observations
  83. GRB 980613 Optical Observations
  84. GRB 980613 optical observations
  85. Discovery of a new SGR source, SGR1627-41
  86. GRB980613 Optical Observations
  87. GRB980613 observations from Palomar
  88. GRB 980613 new optical/IR observations
  89. GRB 980613 optical/IR obs.
  90. GRB980613 Near Infra-Red Observations
  91. GRB971214 Secondary Standards
  92. SGR 1900+14
  93. GRB980519 Secondary Standards
  94. SGR1900+14
  95. SGR1900+14
  96. GRB 980519 Optical Observations
  97. GRB980519 optical observations
  98. GRB980519 I-band observations
  99. GRB 980519
  100. GRB980519 optical observations

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