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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"

36681 results found.

  1. GRB 990123; Addendum to GCN 223
  2. GRB 990123: BATSE Observations
  3. GRB 990123 Keck Spectrum update
  4. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  5. GRB990123 Optical Observations
  6. GRB 990123 Spectroscopic Redshifts
  7. GRB 990123: New Optical Observations, Decay Measure
  8. GRB 990123 Optical Follow-Up
  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 observation
  15. GRB 990123: Optical Decay Slope
  16. GRB 990123 r-band photometry
  17. GRB 990123 Optical Follow-up
  18. GRB990123, early optical counterpart detection
  19. GRB990123 Optical Observation
  20. GRB 990123: Bright New Source, Possible Optical Transient
  21. GRB 990123, Radio observations
  22. SN 1999E & GRB 980919
  23. Possible identification of SN1999E with GRB980910
  24. Optical Observations of GRB 981220
  25. GRB 981226: radio variable
  26. GRB981220
  27. GRB981220, Optical Observations
  28. GRB 981220 Optical observations
  29. GRB 981226 Optical Observations
  30. GRB 980613: Spectroscopy of the host galaxy
  31. GRB981226, sub-millimeter observations
  32. GRB981220, sub-millimeter observations
  33. GRB 981220 and GRB 981226, optical observations
  34. GRB 981226 radio observations
  35. GRB 981226
  36. GRB 981226 optical observations
  37. radio observations of GRB 981226
  38. GRB981220 B, R and I band observations
  39. GRB 981220:Optical Observations
  40. GRB 981220 optical R and I observations
  41. GRB981226, BeppoSAX Christmas GRB
  42. GRB 981226 - Infrared Observations
  43. GRB 981226 optical observations
  44. GRB 981220
  45. GRB 981220, radio observations
  46. GRB981226 Optical Observation
  47. GRB 981220, radio observations
  48. GRB 981220: BeppoSAX/GRBM results
  49. GRB981220 I-band Observations
  50. GRB 981220
  51. GRB 981220 Optical Observations
  52. GRB 981220, optical observations
  53. GRB 980326/Host Galaxy
  54. GRB981220 IPN error box
  55. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  56. GRB980329 R,I flux calibration and R,I,K upper limits
  57. GRB980425: X-ray revised positions
  58. GRB 980923 BATSE Observations
  59. GRB980703 Very Long Baseline Interferometry
  60. GRB970508 optical observations
  61. GRB971214, association with a Galactic star?
  62. Optical Observations of the Host Galaxy of GRB 980519
  63. GRB980519, Optical Observations
  64. GRB980703, Host galaxy multicolor photometry
  65. GRB980703 - BeppoSAX/GRBM detection
  66. GRB 980703 (NFI observations)
  67. GRB980703 optical photometry
  68. GRB 980703: BATSE Observations
  69. GRB980703: Radio transient
  70. GRB980703 H-band Observations
  71. GRB 980703: Spectrum of the proposed optical counterpart
  72. RXTE Observation of GRB 980706
  73. GRB980703: Spectrum of the proposed optical counterpart
  74. GRB980703 Transient Optical Follow-Up
  75. GRB980703: LOTIS observation at early times
  76. GRB980613 Optical Observations
  77. GRB 980703
  78. GRB 980703 H-band Observations
  79. GRB980703 (optical R observations)
  80. GRB980706
  81. GRB980703: radio source/optical transient
  82. BeppoSAX NFI observations of GRB 980703
  83. GRB 980703: ASM Position & Intensity
  84. GRB980703
  85. GRB980703 optical followup
  86. GRB 980613 Near-IR observations
  87. GRB980613, optical observations
  88. GRB 980613: Optical transient and its host galaxy
  89. GRB 980613: Detection of the probable host galaxy
  90. GRB 980613: BATSE Observations
  91. GRB 980613 Optical Observations
  92. GRB 980613 optical observations
  93. GRB980613 Optical Observations
  94. GRB980613 observations from Palomar
  95. GRB980613 BeppoSAX-NFI follow up
  96. GRB 980613 new optical/IR observations
  97. GRB 980613 optical/IR obs.
  98. GRB980613 Near Infra-Red Observations
  99. GRB980611
  100. GRB980613, BeppoSAX WFC positions

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