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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"

32801 results found.

  1. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  2. GRB 990123: Publicly available reduced HST images
  3. GRB990123, Upcoming HST Service Observations
  4. GRB 990123: New Constraints on Possible Foreground Galaxies
  5. GRB990123 Optical Observations
  6. GRB990123, Probability of gravitational lensing
  7. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  8. GRB 990123: Continued Radio Observations
  9. GRB990123, Preliminary Lens Search Results
  10. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  11. On the Lensing Interpretation of GRB 990123
  12. Search for Potential Images of GRB 990123
  13. Search for Potential Images of GRB 990123
  14. GRB990123, Optical BVRI Observations
  15. GRB 990123: near-infrared observations.
  16. GRB990123, OSSE observations
  17. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  18. "GRB 990123: New BV Observations"
  19. GRB 990123 Optical Follow-Up
  20. GRB 990123; Addendum to GCN 223
  21. GRB 990123: BATSE Observations
  22. GRB 990123 Keck Spectrum update
  23. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  24. GRB990123 Optical Observations
  25. GRB 990123 Spectroscopic Redshifts
  26. GRB 990123: New Optical Observations, Decay Measure
  27. GRB 990123 Optical Follow-Up
  28. GRB 990123: Possible Gravitationally Lensed Burst?
  29. GRB 990123 optical observations
  30. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  31. GRB 990123 radio observations
  32. GRB 990123, new radio source
  33. GRB990123, Optical observation
  34. GRB 990123: Optical Decay Slope
  35. GRB 990123 r-band photometry
  36. GRB 990123 Optical Follow-up
  37. GRB990123, early optical counterpart detection
  38. GRB990123 Optical Observation
  39. GRB 990123: Bright New Source, Possible Optical Transient
  40. GRB 990123, Radio observations
  41. SN 1999E & GRB 980919
  42. Possible identification of SN1999E with GRB980910
  43. Optical Observations of GRB 981220
  44. GRB 981226: radio variable
  45. GRB981220
  46. GRB981220, Optical Observations
  47. GRB 981220 Optical observations
  48. GRB 981226 Optical Observations
  49. GRB 980613: Spectroscopy of the host galaxy
  50. GRB981226, sub-millimeter observations
  51. GRB981220, sub-millimeter observations
  52. GRB 981220 and GRB 981226, optical observations
  53. GRB 981226 radio observations
  54. GRB 981226
  55. GRB 981226 optical observations
  56. radio observations of GRB 981226
  57. GRB981220 B, R and I band observations
  58. GRB 981220:Optical Observations
  59. GRB 981220 optical R and I observations
  60. GRB981226, BeppoSAX Christmas GRB
  61. GRB 981226 - Infrared Observations
  62. GRB 981226 optical observations
  63. GRB 981220
  64. GRB 981220, radio observations
  65. GRB981226 Optical Observation
  66. GRB 981220, radio observations
  67. GRB 981220: BeppoSAX/GRBM results
  68. GRB981220 I-band Observations
  69. GRB 981220
  70. GRB 981220 Optical Observations
  71. GRB 981220, optical observations
  72. GRB 980326/Host Galaxy
  73. GRB981220 IPN error box
  74. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  75. GRB980329 R,I flux calibration and R,I,K upper limits
  76. GRB980425: X-ray revised positions
  77. GRB 980923 BATSE Observations
  78. GRB980703 Very Long Baseline Interferometry
  79. GRB970508 optical observations
  80. GRB971214, association with a Galactic star?
  81. Optical Observations of the Host Galaxy of GRB 980519
  82. GRB980519, Optical Observations
  83. GRB980703, Host galaxy multicolor photometry
  84. GRB980703 - BeppoSAX/GRBM detection
  85. GRB 980703 (NFI observations)
  86. GRB980703 optical photometry
  87. GRB 980703: BATSE Observations
  88. GRB980703: Radio transient
  89. GRB980703 H-band Observations
  90. GRB 980703: Spectrum of the proposed optical counterpart
  91. RXTE Observation of GRB 980706
  92. GRB980703: Spectrum of the proposed optical counterpart
  93. GRB980703 Transient Optical Follow-Up
  94. GRB980703: LOTIS observation at early times
  95. GRB980613 Optical Observations
  96. GRB 980703
  97. GRB 980703 H-band Observations
  98. GRB980703 (optical R observations)
  99. GRB980706
  100. GRB980703: radio source/optical transient

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