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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"

21812 results found.

  1. GRB990308 (Trig. 7457), optical observations
  2. GRB990308, Possible new SGR~0209+70
  3. GRB 981220, radio observations
  4. GRB 990217 Optical Observations
  5. GRB 990217, radio observations
  6. Optical Observations of GRB990217
  7. GRB990123 observations
  8. GRB990123, Optical Observation
  9. GRB 990123: Discovery of the Probable Host Galaxy
  10. GRB 990123: Reduced HST Images
  11. For Immediate Posting to GCN - HST Data GRB 990123 Available
  12. GRB19990123 observations
  13. GRB 990123: Updated Keck Spectroscopy Results
  14. GRB981220, field photometry
  15. GRB 990123 NOT Spectrum Update
  16. GRB990123, Optical observation
  17. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  18. GRB 990123: Publicly available reduced HST images
  19. GRB990123, Upcoming HST Service Observations
  20. GRB990123, 15-GHz limits
  21. GRB 990123: New Constraints on Possible Foreground Galaxies
  22. GRB990123 Optical Observations
  23. GRB990123, Probability of gravitational lensing
  24. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  25. GRB 990123: Continued Radio Observations
  26. GRB990123, Preliminary Lens Search Results
  27. On the Lensing Interpretation of GRB 990123
  28. Search for Potential Images of GRB 990123
  29. GRB990123, Optical BVRI Observations
  30. GRB 990123: near-infrared observations.
  31. GRB990123, OSSE observations
  32. GRB990123: NIR Observation
  33. "GRB 990123: New BV Observations"
  34. GRB 990123 Optical Follow-Up
  35. GRB 990123; Addendum to GCN 223
  36. GRB 990123: BATSE Observations
  37. GRB 990123 Keck Spectrum update
  38. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  39. GRB990123 Optical Observations
  40. GRB 990123 Spectroscopic Redshifts
  41. GRB 990123: New Optical Observations, Decay Measure
  42. GRB 990123 Optical Follow-Up
  43. GRB 990123: Possible Gravitationally Lensed Burst?
  44. GRB990123, optical observation
  45. GRB 990123 optical observations
  46. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  47. GRB 990123 radio observations
  48. GRB 990123, new radio source
  49. GRB990123 optical observations
  50. GRB990123, Optical observation
  51. GRB 990123 Optical Follow-up
  52. GRB 990123: Bright New Source, Possible Optical Transient
  53. GRB 990123, Radio observations
  54. SN 1999E & GRB 980919
  55. Possible identification of SN1999E with GRB980910
  56. Optical Observations of GRB 981220
  57. GRB 981226: radio variable
  58. GRB981220
  59. GRB981220, Correction to GCN 179
  60. GRB981220, Optical Observations
  61. GRB 981220 Optical observations
  62. GRB 981226 Optical Observations
  63. GRB 980613: Spectroscopy of the host galaxy
  64. GRB981226, sub-millimeter observations
  65. GRB981220, sub-millimeter observations
  66. GRB 981220 and GRB 981226, optical observations
  67. GRB981226 Optical Observations
  68. GRB 981226 radio observations
  69. GRB 981226
  70. GRB 981226 optical observations
  71. radio observations of GRB 981226
  72. GRB981220 B, R and I band observations
  73. Optical Observations of GRB981226
  74. GRB 981220:Optical Observations
  75. GRB 981220 optical R and I observations
  76. GRB981226, BeppoSAX Christmas GRB
  77. GRB 981226 - Infrared Observations
  78. GRB 981226 optical observations
  79. GRB 981220
  80. GRB 981220, radio observations
  81. GRB 981220, radio observations
  82. GRB981220 I-band Observations
  83. GRB981220 Optical Observations
  84. GRB 981220
  85. GRB 981220 Optical Observations
  86. GRB 981220, optical observations
  87. GRB 980326/Host Galaxy
  88. GRB980329 R,I flux calibration and R,I,K upper limits
  89. GRB980425 Optical Follow-up
  90. GRB980425: X-ray revised positions
  91. GRB 980923 BATSE Observations
  92. SGR1900+14, BeppoSAX-GRBM observations
  93. GRB980703 Very Long Baseline Interferometry
  94. GRB970508 optical observations
  95. GRB971214, association with a Galactic star?
  96. Optical Observations of the Host Galaxy of GRB 980519
  97. GRB980519, Optical Observations
  98. GRB980703, Host galaxy multicolor photometry
  99. GRB 980703 (NFI observations)
  100. GRB980703 optical photometry

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