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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"

24658 results found.

  1. GRB990323 PRECISE IPN POSITION
  2. GRB 990316 Optical Observations
  3. GRB 990316 optical observations
  4. GRB990316: simultaneous optical observation
  5. GRB990316 - Optical null results
  6. GRB990308 not a new SGR
  7. GRB 990308a and GRB 990308b
  8. GRB990308, Possible new SGR~0209+70
  9. GRB 990123, Field Photometry
  10. GRB 990217 Optical Observations
  11. BATSE Flight Anomaly
  12. GRB990217: BeppoSAX/GRBM data
  13. GRB990123 observations
  14. GRB990217 Optical observation
  15. GRB990123, Optical Observation
  16. GRB 990123: Discovery of the Probable Host Galaxy
  17. GRB 990123: Reduced HST Images
  18. GRB19990123 observations
  19. GRB 990123: BVRI standards in the field
  20. GRB981220, field photometry
  21. GRB990123, Optical observation
  22. GRB990123, 15-GHz limits
  23. GRB 990123: New Constraints on Possible Foreground Galaxies
  24. GRB990123 Optical Observations
  25. GRB990123, Probability of gravitational lensing
  26. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  27. GRB990123, Preliminary Lens Search Results
  28. On the Lensing Interpretation of GRB 990123
  29. Search for Potential Images of GRB 990123
  30. Search for Potential Images of GRB 990123
  31. GRB990123, Optical BVRI Observations
  32. GRB 990123: near-infrared observations.
  33. GRB990123, OSSE observations
  34. GRB990123: NIR Observation
  35. GRB990123, ASCA X-ray observation of afterglow
  36. "GRB 990123: New BV Observations"
  37. GRB 990123 Optical Follow-Up
  38. GRB 990123: BATSE Observations
  39. GRB990123 Optical Observations
  40. GRB 990123: New Optical Observations, Decay Measure
  41. GRB 990123 Optical Follow-Up
  42. GRB 990123: Possible Gravitationally Lensed Burst?
  43. GRB990123, optical observation
  44. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  45. GRB990123, Optical observation
  46. GRB 990123: Optical Decay Slope
  47. GRB 990123 r-band photometry
  48. GRB 990123 Optical Follow-up
  49. GRB990123, early optical counterpart detection
  50. GRB990123 Optical Observation
  51. Possible identification of SN1999E with GRB980910
  52. Optical Observations of GRB 981220
  53. GRB 981226: radio variable
  54. GRB981220
  55. GRB981220, Correction to GCN 179
  56. GRB 981220 Optical observations
  57. GRB 981226 Optical Observations
  58. GRB 981220 and GRB 981226, optical observations
  59. GRB981226 Optical Observations
  60. GRB981226 BeppoSAX follow up
  61. GRB 981226
  62. GRB 981226 optical observations
  63. GRB981220 B, R and I band observations
  64. Optical Observations of GRB981226
  65. GRB 981220:Optical Observations
  66. GRB 981226 optical observations
  67. GRB 981220
  68. GRB 981220, radio observations
  69. GRB981220 I-band Observations
  70. GRB 981220
  71. GRB 980326/Host Galaxy
  72. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  73. BeppoSAX NFI Observation of GRB980425
  74. GRB980329 R,I flux calibration and R,I,K upper limits
  75. GRB980425 Optical Follow-up
  76. GRB 980923 BATSE Observations
  77. SGR1900+14, BeppoSAX-GRBM observations
  78. GRB970508 optical observations
  79. GRB971214, association with a Galactic star?
  80. GRB980519, Optical Observations
  81. GRB980703 - BeppoSAX/GRBM detection
  82. GRB980703 optical photometry
  83. GRB 980703: BATSE Observations
  84. GRB980703 optical observations
  85. GRB980703: Radio transient
  86. GRB 980703: Spectrum of the proposed optical counterpart
  87. GRB980703 Transient Optical Follow-Up
  88. GRB980703: LOTIS observation at early times
  89. GRB980613 Optical Observations
  90. GRB980703 (I band observations)
  91. BeppoSAX NFI observations of GRB 980703
  92. GRB980519 observation report
  93. GRB980703 optical followup
  94. Radio observations of SGRs
  95. SGR1900+14 field optical observations
  96. GRB980613, optical observations
  97. GRB 980613: Optical transient and its host galaxy
  98. SGR1627-41, RXTE/ASM observations
  99. GRB 980613: Detection of the probable host galaxy
  100. Reduced error box of SGR 1627-41

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