Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

7396 results found.

  1. GRB 050502: Confirmed variability of the afterglow candidate +
  2. GRB050502 - Correction on the Optical Candidate from the Liverpool
  3. GRB050502 - Optical Candidate from the Liverpool Telescope
  4. GRB 050421: NIR observations
  5. GRB 050416b: Tentative Swift XRT Position
  6. GRB050416: P200 NIR Observations
  7. GRB 050416: Swift XRT Position
  8. GRB 050416: Radio observations
  9. GRB050416: P60 Afterglow Candidate
  10. GRB 050412 : XingLong optical observation
  11. GRB 050408: Subaru Observations
  12. GRB 050408 Optical Observations
  13. GRB 050408: Magellan astrometry and photometry
  14. GRB 050408: First Optical observations with TFOSC at the RTT150
  15. GRB 050408 optical candidate
  16. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  17. GRB 050401 Optical Observations
  18. GRB050402: XDSS counterpart
  19. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  20. GRB 050401: Optical afterglow confirmed
  21. GRB 050401: Optical afterglow candidate
  22. GRB 050319 R band observations
  23. GRB 050319: NIR afterglow candidate
  24. GRB 050319:Near IR afterglow
  25. GRB050319: BR optical photometry
  26. GRB 050319 : Confirmation of optical afterglow decay
  27. GRB 050315, SMARTS optical afterglow decay
  28. GRB050316: MASTER optical observations
  29. GRB 050315, SMARTS optical/IR afterglow observations
  30. GRB 050315: Absorption redshift
  31. GRB 050306: Radio Observations
  32. GRB 050306: Confirmation of X-ray afterglow
  33. GRB 050309, Early optical limits from RAPTOR
  34. GRB 050306: CORRECTION to date of observation
  35. GRB 050306: R-band observations
  36. GRB 050306: No Swift UVOT Optical Counterpart Detected
  37. GRB 050306: REM optical-infrared observations
  38. GRB 050306: Possible X-ray Afterglow Position from the Swift
  39. GRB 050126: Confirmation of the NIR afterglow candidate
  40. GRB 050219b: candidate NIR afterglow
  41. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  42. GRB 050215B: Radio Observations
  43. GRB 050215b: XRT confirmation of IR afterglow candidate
  44. GRB050215b: P60 Optical Observations
  45. GRB 050215b: Swift XRT Source Variability
  46. GRB 050215B: candidate afterglow
  47. GRB 050124: Radio Observations
  48. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  49. GRB 050126: Radio Observations
  50. GRB 050128: Swift XRT prompt afterglow position
  51. GRB 050123 : I-band follow-up observation
  52. GRB041223: decay of the afterglow
  53. GRB041223: optical and NIR observations with REM
  54. GRB 041219 : optical follow-up observations
  55. Deep RAPTOR observations during GRB 041219
  56. GRB041218: Continued P60 Optical Observations
  57. GRB 041219: Infrared Afterglow Candidate
  58. GRB 041219: Infrared Afterglow Candidate
  59. GRB 041217: PROMPT Observations
  60. GRB041218: optical observations
  61. GRB 041218; optical candidate
  62. GRB 041218: Optical observations
  63. GRB041211, Faulkes Telescope optical observation
  64. GRB041006: Fading X-ray Afterglow Observed with Chandra
  65. GRB 041006 : Optical follow-up observation at TAROT
  66. GRB041006: Fading of optical afterglow candidate
  67. GRB 041006 : Optical follow-up observation at KISO
  68. GRB 041006: Finding chart
  69. GRB 041006: Optical afterglow candidate
  70. radio observations, GRB 040924
  71. GRB040924,optical observation
  72. GRB 040924: detection of possible host galaxy by Subaru
  73. GRB040924, RTT150 optical observation
  74. GRB040924: Afterglow magnitude at t=17.5hr
  75. GRB040924 : Optical candidate observations at Lulin observatory
  76. GRB040924 : Optical candidate observations at Lulin observatory
  77. GRB 040924: Subaru NIR observation
  78. GRB040924: Optical afterglow properties
  79. IPN triangulation of GRB040924 (H3564)
  80. GRB040924 (H3564): Optical afterglow candidate
  81. XRF 040912: Radio Observations
  82. XRF 040916: Radio Observations
  83. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  84. XRF040916: continuing decay of OT
  85. TAROT Observations of GRB 040916 (HETE #3558)
  86. GRB040912(=H3557): Candidate Optical Afterglow
  87. XRF040916, optical observations
  88. XRF040916: Optical Transient Candidate by Subaru
  89. XRF040916, Ic observations
  90. XRF040916: optical follow-up observations
  91. GRB040916: Archival optical observations
  92. GRB040916: Optical observations
  93. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  94. GRB 040912, BVRI observations
  95. HETE 3557: Optical observations
  96. GRB 040827 - Radio Observations
  97. GRB040825A: Optical observations
  98. GRB040825A: Optical observations
  99. GRB 040825: Optical observations
  100. XRF040812: possible afterglow second Chandra observation

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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