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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"

25571 results found.

  1. GRB 990123: Continued Radio Observations
  2. GRB990123, Preliminary Lens Search Results
  3. On the Lensing Interpretation of GRB 990123
  4. Search for Potential Images of GRB 990123
  5. Search for Potential Images of GRB 990123
  6. GRB 990123: near-infrared observations.
  7. GRB990123, OSSE observations
  8. GRB990123: NIR Observation
  9. "GRB 990123: New BV Observations"
  10. GRB 990123 Optical Follow-Up
  11. GRB 990123; Addendum to GCN 223
  12. GRB 990123: BATSE Observations
  13. GRB 990123 Keck Spectrum update
  14. GRB990123 IPN annulus
  15. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  16. GRB990123 Optical Observations
  17. GRB 990123 Spectroscopic Redshifts
  18. GRB 990123: New Optical Observations, Decay Measure
  19. GRB 990123: Possible Gravitationally Lensed Burst?
  20. GRB990123, optical observation
  21. GRB 990123 radio observations
  22. GRB990123, Optical observation
  23. GRB 990123: Optical Decay Slope
  24. GRB 990123 r-band photometry
  25. GRB 990123 Optical Follow-up
  26. GRB990123, early optical counterpart detection
  27. GRB990123 Optical Observation
  28. GRB 990123: Bright New Source, Possible Optical Transient
  29. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  30. SN 1999E & GRB 980919
  31. Possible identification of SN1999E with GRB980910
  32. Optical Observations of GRB 981220
  33. GRB981220
  34. GRB981220, Correction to GCN 179
  35. GRB 981220 Optical observations
  36. GRB 981226 Optical Observations
  37. GRB 980613: Spectroscopy of the host galaxy
  38. GRB981226, sub-millimeter observations
  39. GRB 981220 and GRB 981226, optical observations
  40. GRB981226 Optical Observations
  41. GRB981226 BeppoSAX follow up
  42. GRB 981226 radio observations
  43. GRB 981226
  44. GRB 981226 optical observations
  45. radio observations of GRB 981226
  46. GRB981220 B, R and I band observations
  47. Optical Observations of GRB981226
  48. GRB981226, BeppoSAX Christmas GRB
  49. GRB 981226 - Infrared Observations
  50. GRB 981220
  51. GRB 981220, radio observations
  52. GRB981226 Optical Observation
  53. GRB981220 I-band Observations
  54. GRB981220 Optical Observations
  55. GRB 981220
  56. GRB 981220, optical observations
  57. GRB 980326/Host Galaxy
  58. GRB981220 IPN error box
  59. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  60. BeppoSAX NFI Observation of GRB980425
  61. GRB980329 R,I flux calibration and R,I,K upper limits
  62. GRB980425: X-ray revised positions
  63. GRB 980923 BATSE Observations
  64. SGR1900+14, BeppoSAX-GRBM observations
  65. GRB980703 Very Long Baseline Interferometry
  66. GRB970508 optical observations
  67. GRB971214, association with a Galactic star?
  68. Optical Observations of the Host Galaxy of GRB 980519
  69. GRB980519, Optical Observations
  70. GRB 980703 (NFI observations)
  71. GRB980703 optical photometry
  72. GRB 980703: BATSE Observations
  73. GRB980703 optical observations
  74. GRB980703: Radio transient
  75. GRB980703 H-band Observations
  76. GRB 980703: Spectrum of the proposed optical counterpart
  77. GRB980703: Spectrum of the proposed optical counterpart
  78. GRB980703 Transient Optical Follow-Up
  79. GRB980703: LOTIS observation at early times
  80. GRB980613 Optical Observations
  81. GRB980703 (I band observations)
  82. GRB 980703 H-band Observations
  83. GRB980703 (optical R observations)
  84. GRB980703: radio source/optical transient
  85. Radio observations of SGRs
  86. SGR1900+14 field optical observations
  87. GRB 980613 Near-IR observations
  88. GRB980613, optical observations
  89. GRB 980613: Optical transient and its host galaxy
  90. GRB 980613: Detection of the probable host galaxy
  91. GRB 980613: BATSE Observations
  92. SGR1627-41, BeppoSAX-GRBM detections
  93. SGR 1627-41
  94. GRB 980613 optical observations
  95. GRB980613 Optical Observations
  96. GRB980613 observations from Palomar
  97. GRB980613 BeppoSAX-NFI follow up
  98. GRB 980613 new optical/IR observations
  99. GRB 980613 optical/IR obs.
  100. GRB980611

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