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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"

22854 results found.

  1. GRB 990506 optical observations
  2. GRB 990506, optical observations
  3. GRB 990506, optical observations from +1 to +3 hours
  4. GRB 990506, optical observations
  5. GRB990506 observation plan
  6. IPN localization for GRB990506
  7. GRB 970228: Redshift and properties of the host galaxy
  8. GRB 990316 Optical Observations
  9. GRB 990316, Radio observations
  10. GRB 990316 optical observations
  11. GRB990316: simultaneous optical observation
  12. ASM/IPN error box for GRB 990308 (BATSE #7457)
  13. GRB990308 (Trig. 7457), optical observations
  14. GRB981220, IPN localization
  15. GRB 990123, Field Photometry
  16. GRB 990217 Optical Observations
  17. GRB 990217, radio observations
  18. BATSE Flight Anomaly
  19. GRB990123 observations
  20. GRB990217, WFC position
  21. GRB990123, Optical Observation
  22. GRB 990123: Discovery of the Probable Host Galaxy
  23. GRB19990123 observations
  24. GRB 990123: BVRI standards in the field
  25. GRB981220, field photometry
  26. GRB990123, Optical observation
  27. GRB990123, Upcoming HST Service Observations
  28. GRB990123, 15-GHz limits
  29. GRB 990123: New Constraints on Possible Foreground Galaxies
  30. GRB990123 Optical Observations
  31. GRB990123, Probability of gravitational lensing
  32. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  33. GRB990123, Preliminary Lens Search Results
  34. On the Lensing Interpretation of GRB 990123
  35. Search for Potential Images of GRB 990123
  36. GRB990123, Optical BVRI Observations
  37. GRB 990123: near-infrared observations.
  38. GRB990123, OSSE observations
  39. GRB990123: NIR Observation
  40. "GRB 990123: New BV Observations"
  41. GRB990123 IPN annulus
  42. GRB 990123 Spectroscopic Redshifts
  43. GRB 990123: New Optical Observations, Decay Measure
  44. GRB 990123 Optical Follow-Up
  45. GRB 990123: Possible Gravitationally Lensed Burst?
  46. GRB990123, optical observation
  47. GRB 990123 optical observations
  48. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  49. GRB 990123 radio observations
  50. GRB 990123: Optical Decay Slope
  51. GRB 990123 r-band photometry
  52. GRB 990123 Optical Follow-up
  53. GRB990123, early optical counterpart detection
  54. GRB990123 Optical Observation
  55. Possible identification of SN1999E with GRB980910
  56. Optical Observations of GRB 981220
  57. GRB 981226: radio variable
  58. GRB981220, Optical Observations
  59. GRB 981226 Optical Observations
  60. GRB981226 Optical Observations
  61. GRB981226 BeppoSAX follow up
  62. GRB 981226
  63. GRB 981226 optical observations
  64. GRB981220 B, R and I band observations
  65. Optical Observations of GRB981226
  66. GRB 981220:Optical Observations
  67. GRB 981226 - Infrared Observations
  68. GRB 981226 optical observations
  69. GRB 981220, radio observations
  70. GRB 981220
  71. GRB 980326/Host Galaxy
  72. GRB981220 IPN error box
  73. BeppoSAX NFI Observation of GRB980425
  74. GRB980329 R,I flux calibration and R,I,K upper limits
  75. GRB980425 Optical Follow-up
  76. GRB980425: X-ray revised positions
  77. GRB 980923 BATSE Observations
  78. GRB970508 optical observations
  79. GRB971214, association with a Galactic star?
  80. GRB980519, Optical Observations
  81. GRB980703 - BeppoSAX/GRBM detection
  82. GRB 980703 (NFI observations)
  83. GRB980703 optical photometry
  84. GRB980703 optical observations
  85. GRB980703: Radio transient
  86. RXTE Observation of GRB 980706
  87. GRB980703 Transient Optical Follow-Up
  88. GRB980703: LOTIS observation at early times
  89. GRB980613 Optical Observations
  90. GRB 980703
  91. BeppoSAX NFI observations of GRB 980703
  92. GRB980703 optical followup
  93. Radio observations of SGRs
  94. SGR1900+14 field optical observations
  95. GRB 980613 Near-IR observations
  96. GRB 980613: Optical transient and its host galaxy
  97. SGR1627-41, RXTE/ASM observations
  98. GRB 980613: Detection of the probable host galaxy
  99. GRB 980613 Optical Observations
  100. GRB 980613 optical observations

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