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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"

15985 results found.

  1. GRB 990506 optical observations
  2. GRB 990506 optical observations
  3. GRB 990506, optical observations
  4. GRB 990506: Limits on the possible optical transient
  5. GRB 990506, armchair astronomy
  6. GRB 990506, optical observations from +1 to +3 hours
  7. GRB 990506, optical observations
  8. GRB990506 Optical observations
  9. GRB980425 Optical observations of exponential decline at late time
  10. GRB 990316 Optical Observations
  11. GRB 990316, Radio observations
  12. GRB 990316, Optical observations
  13. GRB990316, Optical observations
  14. GRB 990316 optical observations
  15. GRB990316: simultaneous optical observation
  16. GRB990316 - Optical null results
  17. GRB990308 (Trig. 7457), optical observations
  18. GRB 990217 Optical Observations
  19. Optical Observations of GRB990217
  20. GRB990123 observations
  21. GRB990217 Optical observation
  22. GRB990123, Optical Observation
  23. GRB 990123: Discovery of the Probable Host Galaxy
  24. GRB 990123: Reduced HST Images
  25. GRB19990123 observations
  26. GRB 990123: Updated Keck Spectroscopy Results
  27. GRB990123, Optical observation
  28. GRB 990123: New Constraints on Possible Foreground Galaxies
  29. GRB990123 Optical Observations
  30. GRB990123, Probability of gravitational lensing
  31. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  32. GRB 990123: Continued Radio Observations
  33. GRB990123, Preliminary Lens Search Results
  34. On the Lensing Interpretation of GRB 990123
  35. Search for Potential Images of GRB 990123
  36. Search for Potential Images of GRB 990123
  37. GRB990123, Optical BVRI Observations
  38. GRB 990123: near-infrared observations.
  39. GRB990123: NIR Observation
  40. "GRB 990123: New BV Observations"
  41. GRB 990123 Optical Follow-Up
  42. GRB 990123: BATSE Observations
  43. GRB990123 IPN annulus
  44. GRB990123 Optical Observations
  45. GRB 990123 Spectroscopic Redshifts
  46. GRB 990123: New Optical Observations, Decay Measure
  47. GRB 990123 Optical Follow-Up
  48. GRB 990123: Possible Gravitationally Lensed Burst?
  49. GRB990123, optical observation
  50. GRB 990123 optical observations
  51. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  52. GRB 990123 radio observations
  53. GRB 990123, new radio source
  54. GRB990123 optical observations
  55. GRB990123, Optical observation
  56. GRB 990123: Optical Decay Slope
  57. GRB 990123 r-band photometry
  58. GRB 990123 Optical Follow-up
  59. GRB990123, early optical counterpart detection
  60. GRB990123 Optical Observation
  61. GRB 990123: Bright New Source, Possible Optical Transient
  62. Optical Observations of GRB 981220
  63. GRB 981226: radio variable
  64. GRB981220, Correction to GCN 179
  65. GRB981220, Optical Observations
  66. GRB 981220 Optical observations
  67. GRB 981226 Optical Observations
  68. GRB 981220 and GRB 981226, optical observations
  69. GRB981226 Optical Observations
  70. GRB 981226 radio observations
  71. GRB 981226
  72. GRB 981226 optical observations
  73. radio observations of GRB 981226
  74. GRB981220 B, R and I band observations
  75. Optical Observations of GRB981226
  76. GRB 981220:Optical Observations
  77. GRB 981220 optical R and I observations
  78. GRB 981226 optical observations
  79. GRB 981220, radio observations
  80. GRB981226 Optical Observation
  81. GRB981220 Optical Observations
  82. GRB 981220 Optical Observations
  83. GRB 981220, optical observations
  84. GRB 980326/Host Galaxy
  85. GRB980329 R,I flux calibration and R,I,K upper limits
  86. GRB980425 Optical Follow-up
  87. GRB970508 optical observations
  88. GRB971214, association with a Galactic star?
  89. Optical Observations of the Host Galaxy of GRB 980519
  90. GRB980519, Optical Observations
  91. GRB980703, Host galaxy multicolor photometry
  92. GRB980703 optical photometry
  93. GRB980703 optical observations
  94. GRB980703 H-band Observations
  95. GRB 980703: Spectrum of the proposed optical counterpart
  96. GRB980703: Spectrum of the proposed optical counterpart
  97. GRB980703 Transient Optical Follow-Up
  98. GRB980613 Optical Observations
  99. GRB980703 (I band observations)
  100. GRB 980703 H-band Observations

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