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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"

45417 results found.

  1. GRB 990123 radio observations
  2. GRB 990123, new radio source
  3. GRB990123 optical observations
  4. GRB990123, Optical observation
  5. GRB 990123: Optical Decay Slope
  6. GRB 990123 r-band photometry
  7. GRB 990123 Optical Follow-up
  8. GRB990123, early optical counterpart detection
  9. GRB990123 Optical Observation
  10. GRB990123, BeppoSAX-NFI X-ray afterglow detection
  11. GRB990123, refined SAX-WFC position
  12. GRB 990123: Bright New Source, Possible Optical Transient
  13. GRB 990123, Radio observations
  14. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  15. SN 1999E & GRB 980919
  16. Possible identification of SN1999E with GRB980910
  17. Optical Observations of GRB 981220
  18. GRB 981226: radio variable
  19. GRB981220
  20. GRB981220, Correction to GCN 179
  21. GRB981220, Optical Observations
  22. GRB 981220 Optical observations
  23. GRB 981226 Optical Observations
  24. GRB 980613: Spectroscopy of the host galaxy
  25. GRB981226, sub-millimeter observations
  26. GRB981220, sub-millimeter observations
  27. GRB 981220 and GRB 981226, optical observations
  28. GRB981226 Optical Observations
  29. GRB981226 BeppoSAX follow up
  30. GRB 981226 radio observations
  31. GRB 981226
  32. GRB 981226 optical observations
  33. radio observations of GRB 981226
  34. GRB981220 B, R and I band observations
  35. GRB981226, BeppoSAX-NFI follow-up
  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. GRB 981220: BeppoSAX/GRBM results
  47. GRB981220 I-band Observations
  48. GRB981220 Optical Observations
  49. GRB 981220
  50. GRB 981220 Optical Observations
  51. GRB 981220, optical observations
  52. GRB 980326/Host Galaxy
  53. GRB981220 IPN error box
  54. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  55. BeppoSAX NFI Observation of GRB980425
  56. GRB980329 R,I flux calibration and R,I,K upper limits
  57. GRB980425 Optical Follow-up
  58. GRB980425: X-ray revised positions
  59. GRB 980923 BATSE Observations
  60. SGR1900+14, BeppoSAX-GRBM observations
  61. GRB980703 Very Long Baseline Interferometry
  62. GRB970508 optical observations
  63. GRB971214, association with a Galactic star?
  64. Optical Observations of the Host Galaxy of GRB 980519
  65. GRB980519, Optical Observations
  66. GRB980703, Host galaxy multicolor photometry
  67. GRB980703 - BeppoSAX/GRBM detection
  68. GRB 980703 (NFI observations)
  69. GRB980703 optical photometry
  70. GRB 980703: BATSE Observations
  71. GRB980703 optical observations
  72. GRB980703: Radio transient
  73. GRB980703 H-band Observations
  74. GRB 980703: Spectrum of the proposed optical counterpart
  75. RXTE Observation of GRB 980706
  76. GRB980703: Spectrum of the proposed optical counterpart
  77. GRB980703 Transient Optical Follow-Up
  78. GRB980703: LOTIS observation at early times
  79. GRB980613 Optical Observations
  80. GRB 980703
  81. GRB980703 (I band observations)
  82. GRB 980703 H-band Observations
  83. GRB980703 (optical R observations)
  84. GRB980706
  85. GRB980703: radio source/optical transient
  86. BeppoSAX NFI observations of GRB 980703
  87. GRB 980703: ASM Position & Intensity
  88. GRB980703
  89. GRB980519 observation report
  90. GRB980703 optical followup
  91. SGR1627-41
  92. Radio observations of SGRs
  93. SGR1900+14 field optical observations
  94. GRB 980613 Near-IR observations
  95. GRB980613, optical observations
  96. GRB 980613: Optical transient and its host galaxy
  97. SGR1627-41, RXTE/ASM observations
  98. SGR1627-41, Refined IPN annulus location
  99. GRB 980613: Detection of the probable host galaxy
  100. Reduced error box of SGR 1627-41

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