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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"

15556 results found.

  1. GRB990123, Probability of gravitational lensing
  2. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  3. GRB 990123: Continued Radio Observations
  4. GRB990123, Preliminary Lens Search Results
  5. On the Lensing Interpretation of GRB 990123
  6. Search for Potential Images of GRB 990123
  7. Search for Potential Images of GRB 990123
  8. GRB990123, Optical BVRI Observations
  9. GRB 990123: near-infrared observations.
  10. GRB990123: NIR Observation
  11. "GRB 990123: New BV Observations"
  12. GRB 990123 Optical Follow-Up
  13. GRB 990123: BATSE Observations
  14. GRB990123 IPN annulus
  15. GRB990123 Optical Observations
  16. GRB 990123 Spectroscopic Redshifts
  17. GRB 990123: New Optical Observations, Decay Measure
  18. GRB 990123 Optical Follow-Up
  19. GRB 990123: Possible Gravitationally Lensed Burst?
  20. GRB990123, optical observation
  21. GRB 990123 optical observations
  22. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  23. GRB 990123 radio observations
  24. GRB 990123, new radio source
  25. GRB990123 optical observations
  26. GRB990123, Optical observation
  27. GRB 990123: Optical Decay Slope
  28. GRB 990123 r-band photometry
  29. GRB 990123 Optical Follow-up
  30. GRB990123, early optical counterpart detection
  31. GRB990123 Optical Observation
  32. GRB 990123: Bright New Source, Possible Optical Transient
  33. Optical Observations of GRB 981220
  34. GRB 981226: radio variable
  35. GRB981220, Correction to GCN 179
  36. GRB981220, Optical Observations
  37. GRB 981220 Optical observations
  38. GRB 981226 Optical Observations
  39. GRB 981220 and GRB 981226, optical observations
  40. GRB981226 Optical Observations
  41. GRB 981226 radio observations
  42. GRB 981226
  43. GRB 981226 optical observations
  44. radio observations of GRB 981226
  45. GRB981220 B, R and I band observations
  46. Optical Observations of GRB981226
  47. GRB 981220:Optical Observations
  48. GRB 981220 optical R and I observations
  49. GRB 981226 optical observations
  50. GRB 981220, radio observations
  51. GRB981226 Optical Observation
  52. GRB981220 Optical Observations
  53. GRB 981220 Optical Observations
  54. GRB 981220, optical observations
  55. GRB 980326/Host Galaxy
  56. GRB980329 R,I flux calibration and R,I,K upper limits
  57. GRB980425 Optical Follow-up
  58. GRB970508 optical observations
  59. GRB971214, association with a Galactic star?
  60. Optical Observations of the Host Galaxy of GRB 980519
  61. GRB980519, Optical Observations
  62. GRB980703, Host galaxy multicolor photometry
  63. GRB980703 optical photometry
  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. GRB980703 Transient Optical Follow-Up
  69. GRB980613 Optical Observations
  70. GRB980703 (I band observations)
  71. GRB 980703 H-band Observations
  72. GRB980703 (optical R observations)
  73. GRB980703: radio source/optical transient
  74. GRB980519 observation report
  75. GRB980703 optical followup
  76. SGR1900+14 field optical observations
  77. GRB 980613 Near-IR observations
  78. GRB980613, optical observations
  79. GRB 980613: Optical transient and its host galaxy
  80. GRB 980613: Detection of the probable host galaxy
  81. GRB 980613 Optical Observations
  82. GRB 980613 optical observations
  83. GRB980613 Optical Observations
  84. GRB980613 observations from Palomar
  85. GRB 980613 new optical/IR observations
  86. GRB 980613 optical/IR obs.
  87. GRB980613 Near Infra-Red Observations
  88. GRB971214 Secondary Standards
  89. GRB980519 Secondary Standards
  90. GRB 980519 Optical Observations
  91. GRB980519 optical observations
  92. GRB980519 I-band observations
  93. GRB 980519
  94. GRB980519 optical observations
  95. GRB 980519 Optical Observations
  96. GRB970519, optical follow-up at Schmidt Calern
  97. GRB980519 optical observations
  98. GRB980519 Optical Observations
  99. GRB980519 Optical Observations
  100. GRB980519 IPN POSITION

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