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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"

24660 results found.

  1. GRB990506 observation plan
  2. IPN localization for GRB990506
  3. GRB990323 PRECISE IPN POSITION
  4. GRB 990316 Optical Observations
  5. GRB 990316 optical observations
  6. GRB990316: simultaneous optical observation
  7. GRB990316 - Optical null results
  8. GRB990308 not a new SGR
  9. GRB 990308a and GRB 990308b
  10. GRB990308, Possible new SGR~0209+70
  11. GRB 990123, Field Photometry
  12. GRB 990217 Optical Observations
  13. BATSE Flight Anomaly
  14. GRB990217: BeppoSAX/GRBM data
  15. GRB990123 observations
  16. GRB990217 Optical observation
  17. GRB990123, Optical Observation
  18. GRB 990123: Discovery of the Probable Host Galaxy
  19. GRB 990123: Reduced HST Images
  20. GRB19990123 observations
  21. GRB 990123: BVRI standards in the field
  22. GRB981220, field photometry
  23. GRB990123, Optical observation
  24. GRB990123, 15-GHz limits
  25. GRB 990123: New Constraints on Possible Foreground Galaxies
  26. GRB990123 Optical Observations
  27. GRB990123, Probability of gravitational lensing
  28. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  29. GRB990123, Preliminary Lens Search Results
  30. On the Lensing Interpretation of GRB 990123
  31. Search for Potential Images of GRB 990123
  32. Search for Potential Images of GRB 990123
  33. GRB990123, Optical BVRI Observations
  34. GRB 990123: near-infrared observations.
  35. GRB990123, OSSE observations
  36. GRB990123: NIR Observation
  37. GRB990123, ASCA X-ray observation of afterglow
  38. "GRB 990123: New BV Observations"
  39. GRB 990123 Optical Follow-Up
  40. GRB 990123: BATSE Observations
  41. GRB990123 Optical Observations
  42. GRB 990123: New Optical Observations, Decay Measure
  43. GRB 990123 Optical Follow-Up
  44. GRB 990123: Possible Gravitationally Lensed Burst?
  45. GRB990123, optical observation
  46. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  47. GRB990123, Optical observation
  48. GRB 990123: Optical Decay Slope
  49. GRB 990123 r-band photometry
  50. GRB 990123 Optical Follow-up
  51. GRB990123, early optical counterpart detection
  52. GRB990123 Optical Observation
  53. Possible identification of SN1999E with GRB980910
  54. Optical Observations of GRB 981220
  55. GRB 981226: radio variable
  56. GRB981220
  57. GRB981220, Correction to GCN 179
  58. GRB 981220 Optical observations
  59. GRB 981226 Optical Observations
  60. GRB 981220 and GRB 981226, optical observations
  61. GRB981226 Optical Observations
  62. GRB981226 BeppoSAX follow up
  63. GRB 981226
  64. GRB 981226 optical observations
  65. GRB981220 B, R and I band observations
  66. Optical Observations of GRB981226
  67. GRB 981220:Optical Observations
  68. GRB 981226 optical observations
  69. GRB 981220
  70. GRB 981220, radio observations
  71. GRB981220 I-band Observations
  72. GRB 981220
  73. GRB 980326/Host Galaxy
  74. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  75. BeppoSAX NFI Observation of GRB980425
  76. GRB980329 R,I flux calibration and R,I,K upper limits
  77. GRB980425 Optical Follow-up
  78. GRB 980923 BATSE Observations
  79. SGR1900+14, BeppoSAX-GRBM observations
  80. GRB970508 optical observations
  81. GRB971214, association with a Galactic star?
  82. GRB980519, Optical Observations
  83. GRB980703 - BeppoSAX/GRBM detection
  84. GRB980703 optical photometry
  85. GRB 980703: BATSE Observations
  86. GRB980703 optical observations
  87. GRB980703: Radio transient
  88. GRB 980703: Spectrum of the proposed optical counterpart
  89. GRB980703 Transient Optical Follow-Up
  90. GRB980703: LOTIS observation at early times
  91. GRB980613 Optical Observations
  92. GRB980703 (I band observations)
  93. BeppoSAX NFI observations of GRB 980703
  94. GRB980519 observation report
  95. GRB980703 optical followup
  96. Radio observations of SGRs
  97. SGR1900+14 field optical observations
  98. GRB980613, optical observations
  99. GRB 980613: Optical transient and its host galaxy
  100. SGR1627-41, RXTE/ASM observations

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