Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. See news and announcements

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"

22197 results found.

  1. GRB 050408: ARC 3.5-meter NIR Observations
  2. Swift UVOT observations of GRB 050701
  3. Swift trigger 143708 is really GRB 050701
  4. GRB 050607, radio observations
  5. GRB050525a: HST Observations
  6. XRF 050509c: Optical monitoring
  7. XRF050509c: Radio Detection
  8. GRB 050607 optical decay
  9. GRB050607: refined analysis of prompt REM observations
  10. Swift/UVOT observations of GRB050607
  11. GRB 050607: PROMPT VRcIc Observations
  12. GRB 050607: Optical decay and spectral slope
  13. GRB050607,optical observation
  14. GRB 050607 - XRT refined data analysis
  15. Optical Afterglow of GRB 050607
  16. GRB050607: Swift Detection of a long GRB
  17. GRB050607: prompt REM observations
  18. GRB 050603: prediction of t_break
  19. Limits on a SN in the field of GRB 050509b
  20. Konus-Wind observation of GRB 050603
  21. GRB050603: Fading Afterglow observed by Swift UVOT
  22. GRB050603, submillimetre observations
  23. GRB050603: Radio Detection
  24. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  25. GRB 050603: INTEGRAL shows it is not a short GRB
  26. Swift/BAT Detection of GRB050603
  27. GRB 050525a, infrared observations
  28. GRB050528, XRT observations
  29. GRB050528: updated Liverpool Telescope limits
  30. Swift-BAT GRB 050528: a soft burst
  31. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  32. Possible GRB050528: no candidate from Liverpool Telescope
  33. Swift-BAT detection of possible GRB 050528
  34. GRB050525a: Radio Observations
  35. GRB 050509b: refined XRT/Chandra afterglow position analysis
  36. GRB 050525: RTT150, Optical observations
  37. GRB 050525a: SARA Observations
  38. GRB 050525B: Swift-BAT observations
  39. GRB 050525: MITSuME Optical Observation in VRI
  40. GRB050525A,optical observation
  41. GRB050525: Super-LOTIS observations
  42. GRB050306: optical afterglow not confirmed
  43. GRB 050525: BART optical observation
  44. GRB 050525A: BOOTES simultaneous optical observations
  45. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  46. Konus-Wind observation of GRB 050525
  47. GRB 050525: TAROT observations of the early afterglow
  48. INTEGRAL detection of GRB 050525
  49. GRB 050525, infrared observations
  50. GRB 050525: observatons of the optical afterglow
  51. GRB050525: ROTSE-III Refined Analysis
  52. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  53. XRF050522: Radio Observations
  54. Swift/UVOT observation of XRF 050522
  55. GRB 050509A: Further I-band imaging
  56. GRB050522,optical observation
  57. GRB050520,optical observation
  58. XRF 050522: Continued NIR P200 Monitoring
  59. Recent GRB BVRcIc field photometry
  60. GRB050520: Radio Observations
  61. XRF 050522: Swift XRT observation
  62. XRF050522, BVRcIc field photometry
  63. XRF050522: Optical Observations
  64. XRF050522: Near-infrared Observations
  65. GRB 050520: VLT/ULTRACAM observations
  66. Swift UVOT Observations of GRB 050520
  67. GRB 050520: Swift XRT refined analysis
  68. XRF 050509c: Swift XRT Upper Limit
  69. XRF050509c: Radio Observations
  70. RBO Observations of GRB050520
  71. GRB 050520: P200 Observations
  72. GRB050520: Liverpool Telescope follow-up
  73. GRB 050520: TAROT optical limit
  74. GRB 050520: VLT/ULTRACAM observations
  75. GRB 050520: OSN optical observations
  76. No Swift-BAT Lightcurves in real-time for next 3 weeks
  77. XRF 050509C: REM NIR and Optical refined analysis
  78. GRB 050504: Swift XRT afterglow candidate has faded
  79. GRB 050509B and short GRB-SN association? (corrected)
  80. GRB 050509B and short GRB-SN association?
  81. GRB050502b: Early Observation
  82. GRB050509b, Bok telescope B-band imaging
  83. GRB050509b, SDSS pre-burst observations
  84. GRB 050509b: Keck/Chandra Cross-Correlation
  85. GRB 050509b: Keck/Chandra Cross-Correlation
  86. Chandra observation of GRB 050509b
  87. GRB 050509b: Swift/UVOT follow-up measurements
  88. GRB050509B: Optical observations at the Very Large Telescope
  89. GRB 050509b: No Optical Variability in XRT Error Circle
  90. GRB050416: Afterglow detection at 188 nm with Swift UVOT
  91. GRB 050509c: ROTSE-III Optical Limits
  92. GRB 050509B: WSRT Radio Observations
  93. GRB 050505, early TAROT observation
  94. GRB050509c: REM NIR and Optical observations
  95. GRB 050505: SARA Observations
  96. GRB 050509B: Swift/XRT refined analysis
  97. GRB 050509b: Optical observations
  98. GRB 050509b: Possible Optical Counterpart
  99. GRB 050509A: Optical observations
  100. GRB050509b: Radio Observations

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov