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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"

37205 results found.

  1. GRB 990123: BVRI standards in the field
  2. GRB 990123: Updated Keck Spectroscopy Results
  3. GRB981220, field photometry
  4. GRB 990123 NOT Spectrum Update
  5. GRB990123, Optical observation
  6. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  7. GRB 990123: Publicly available reduced HST images
  8. GRB990123, Upcoming HST Service Observations
  9. GRB 990123: New Constraints on Possible Foreground Galaxies
  10. GRB990123 Optical Observations
  11. GRB990123, Probability of gravitational lensing
  12. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  13. GRB 990123: Continued Radio Observations
  14. GRB990123, Preliminary Lens Search Results
  15. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  16. On the Lensing Interpretation of GRB 990123
  17. Search for Potential Images of GRB 990123
  18. Search for Potential Images of GRB 990123
  19. GRB990123, Optical BVRI Observations
  20. GRB 990123: near-infrared observations.
  21. GRB990123, OSSE observations
  22. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  23. "GRB 990123: New BV Observations"
  24. GRB 990123 Optical Follow-Up
  25. GRB 990123; Addendum to GCN 223
  26. GRB 990123: BATSE Observations
  27. GRB 990123 Keck Spectrum update
  28. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  29. GRB990123 Optical Observations
  30. GRB 990123 Spectroscopic Redshifts
  31. GRB 990123: New Optical Observations, Decay Measure
  32. GRB 990123 Optical Follow-Up
  33. GRB 990123: Possible Gravitationally Lensed Burst?
  34. GRB 990123 optical observations
  35. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  36. GRB 990123 radio observations
  37. GRB 990123, new radio source
  38. GRB990123, Optical observation
  39. GRB 990123: Optical Decay Slope
  40. GRB 990123 r-band photometry
  41. GRB 990123 Optical Follow-up
  42. GRB990123, early optical counterpart detection
  43. GRB990123 Optical Observation
  44. GRB 990123: Bright New Source, Possible Optical Transient
  45. GRB 990123, Radio observations
  46. SN 1999E & GRB 980919
  47. Possible identification of SN1999E with GRB980910
  48. Optical Observations of GRB 981220
  49. GRB 981226: radio variable
  50. GRB981220
  51. GRB981220, Optical Observations
  52. GRB 981220 Optical observations
  53. GRB 981226 Optical Observations
  54. GRB 980613: Spectroscopy of the host galaxy
  55. GRB981226, sub-millimeter observations
  56. GRB981220, sub-millimeter observations
  57. GRB 981220 and GRB 981226, optical observations
  58. GRB 981226 radio observations
  59. GRB 981226
  60. GRB 981226 optical observations
  61. radio observations of GRB 981226
  62. GRB981220 B, R and I band observations
  63. GRB 981220:Optical Observations
  64. GRB 981220 optical R and I observations
  65. GRB981226, BeppoSAX Christmas GRB
  66. GRB 981226 - Infrared Observations
  67. GRB 981226 optical observations
  68. GRB 981220
  69. GRB 981220, radio observations
  70. GRB981226 Optical Observation
  71. GRB 981220, radio observations
  72. GRB 981220: BeppoSAX/GRBM results
  73. GRB981220 I-band Observations
  74. GRB 981220
  75. GRB 981220 Optical Observations
  76. GRB 981220, optical observations
  77. GRB 980326/Host Galaxy
  78. GRB981220 IPN error box
  79. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  80. GRB980329 R,I flux calibration and R,I,K upper limits
  81. GRB980425: X-ray revised positions
  82. GRB 980923 BATSE Observations
  83. GRB980703 Very Long Baseline Interferometry
  84. GRB970508 optical observations
  85. GRB971214, association with a Galactic star?
  86. Optical Observations of the Host Galaxy of GRB 980519
  87. GRB980519, Optical Observations
  88. GRB980703, Host galaxy multicolor photometry
  89. GRB980703 - BeppoSAX/GRBM detection
  90. GRB 980703 (NFI observations)
  91. GRB980703 optical photometry
  92. GRB 980703: BATSE Observations
  93. GRB980703: Radio transient
  94. GRB980703 H-band Observations
  95. GRB 980703: Spectrum of the proposed optical counterpart
  96. RXTE Observation of GRB 980706
  97. GRB980703: Spectrum of the proposed optical counterpart
  98. GRB980703 Transient Optical Follow-Up
  99. GRB980703: LOTIS observation at early times
  100. GRB980613 Optical Observations

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