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"

914 results found.

  1. GRB 210919A: MITSuME Akeno optical upper limits
  2. GRB 210824A: MITSuME Akeno optical upper limits
  3. GRB 210802A: MITSuME Okayama optical upper limits
  4. GRB 210725A: MITSuME Akeno optical upper limits
  5. GRB 210619B: CAHA 2.2m photometric monitoring
  6. GRB 210610B: MITSuME Akeno optical observation
  7. GRB 210610B: optical afterglow observations
  8. GRB 210610A: MITSuME Ishigaki optical observation
  9. GRB 210610A: MITSuME Akeno optical observation
  10. GRB 210528B: MITSuME Akeno optical upper limits
  11. GRB 210527A: MITSuME Akeno optical upper limits
  12. AMON IC_HAWC NuEm-210515A / NuEm-210515B : No neutrino counterpart detected with ANTARES
  13. GRB 210504A: MITSuME Akeno optical upper limits
  14. GRB 210424B: MITSuME Akeno optical upper limits
  15. GRB 210421A: MITSuME Akeno optical upper limits
  16. GRB 210413B: MITSuME Okayama optical upper limits
  17. GRB 210419C: MITSuME Akeno optical upper limits
  18. GRB 210410A: MITSuME Akeno optical upper limits
  19. GRB 210312B: OSN Afterglow Observations
  20. GRB 210318B: MITSuME Okayama optical upper limits
  21. GRB 210308A: MITSuME Okayama optical upper limits
  22. GRB 210306A: MITSuME Akeno optical observation
  23. GRB 210222B: MITSuME Akeno optical upper limits
  24. GRB 210218A: MITSuME Akeno optical upper limits
  25. GRB 210212A: MITSuME Akeno optical upper limits
  26. GRB 210210A: CAHA detection and likely jet break
  27. GRB 210112A: LBT host detection and correction to GCN 29319 (CAHA observations)
  28. GRB 210209A: MITSuME Akeno optical upper limits
  29. GRB 210205A: MITSuME Ishigaki optical observation
  30. GRB 210112A: Deep CAHA 2.2m detection
  31. GRB 201015A: evidence of supernova in LBT spectra
  32. GRB 210112A: OSN second epoch, decay
  33. GRB 210112A: OSN Reddened Afterglow Detection
  34. NuEm-210111A : No neutrino counterpart in ANTARES
  35. GRB 210104A: MITSuME Ishigaki optical observation
  36. GRB 210104A: MITSuME Akeno optical observation
  37. GRB 201223A: MITSuME Akeno optical observation
  38. GRB 201214B: MITSuME Akeno optical upper limits
  39. GRB 201203A: MITSuME Okayama optical upper limits
  40. AMON IC_HAWC NuEm-201124A: No Neutrino Counterpart detected with ANTARES
  41. GRB 201104B: MITSuME Akeno optical observation
  42. GRB 201027A: MITSuME Akeno optical upper limits
  43. GRB 201024A: MITSuME Akeno optical upper limits
  44. GRB 201020A: MITSuME Akeno optical observation
  45. GRB 201017A: MITSuME Akeno optical upper limits
  46. IceCube-201007A: No candidate counterparts from the Zwicky Transient Facility
  47. GRB 201006A: MITSuME Akeno optical upper limits
  48. GRB 201001A: MITSuME Akeno optical upper limits
  49. GRB 200925B: OSN Afterglow Candidate Discovery
  50. GRB 200907B: MITSuME Okayama optical upper limits
  51. GRB 200906A: OSN 1.5m Upper Limit
  52. GRB 200829A: further SAO RAS optical observations
  53. GRB 200829A: SAO RAS optical observations
  54. GRB 200819A: MITSuME Ishigaki optical upper limits
  55. GRB 200819A: MITSuME Akeno optical upper limits
  56. GRB 200806A: MITSuME Akeno optical upper limits
  57. AMON IC_HAWC 170720: No Neutrino Counterpart detected with ANTARES
  58. IceCube-200530A - SN2020lls likely unrelated
  59. GRB 200613A: MITSuME Akeno optical upper limits
  60. GRB 200529A: MITSuME Akeno optical upper limits
  61. GRB 200528A: CAHA Upper Limit
  62. GRB 200528A: MITSuME Akeno optical upper limits
  63. GRB 200524A: optical upper limits from further MITSuME Akeno observation
  64. GRB 200524A: MITSuME Akeno optical observation
  65. GRB 200524A: CAHA multicolor afterglow detection
  66. GRB 200514A: MITSuME Akeno optical upper limits
  67. Gagarin-day GRB 200412B: observations with the 3.6m Devasthal Optical Telescope
  68. GRB 200412B: MITSuME Akeno optical observation
  69. GRB 200324A:MITSuME Akeno optical upper limits
  70. GRB 200227A: MITSuME Akeno optical upper limit
  71. GRB 200224A: Calar Alto 2.2m optical afterglow detection
  72. LIGO/Virgo S200213t: CLU/NED Galaxies in the 4-Update Localization Volume
  73. LIGO/Virgo S200213t: No candidates found in J-GEM follow-up observations
  74. LIGO/Virgo S200213t: NED Galaxies in the 90% Localization Volume
  75. GRB 200122A: MITSuME Akeno optical upper limits
  76. LIGO/Virgo S200114f: SOAR spectroscopy of AT2020zf, AT2020ace and AT2020ach
  77. GRB 200115A: MITSuME Okayama optical upper limits
  78. GRB 191227A: MITSuME Akeno optical upper limits
  79. LIGO/Virgo S191213g: YAHPT Observations of AT2019wxt(PS19hgw)
  80. LIGO/Virgo S191216ap: No candidates found in J-GEM follow-up observations of HAWC error region
  81. LIGO/Virgo S191213g: No candidates found in J-GEM follow-up observations
  82. LIGO/Virgo S191205ah: MITSuME Observation of MASTER OT J123123.61-043847.2
  83. GRB 191031D: MITSuME Akeno optical upper limits
  84. GRB191016A: MITSuME Okayama optical observation
  85. LIGO/Virgo S190930t: J-GEM follow-up observations for AT2019rpj
  86. GRB 191001B: MITSuME Akeno optical upper limits
  87. GRB 190926A: Upper Limit from OSN T150 Observation
  88. GRB 190926A: MITSuME Akeno optical upper limits
  89. GRB 190829A: GTC confirmation of an associated Type Ic-BL Supernova
  90. LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidate AT2019ntp
  91. LIGO/Virgo S190822c: CLU/NED Galaxies in the 50% Localization Volume
  92. LIGO/Virgo S190814bv: No candidates found in J-GEM follow-up observations
  93. LIGO/Virgo S190814bv: CLU/NED Galaxies in the 50% Localization Volume
  94. LIGO/Virgo S190808ae: CLU/NED Galaxies in the 50% Localization Volume
  95. IceCube-190730A: MASTER optical observation
  96. LIGO/Virgo S190728q: MITSuME Okayama and Bisei Follow-Up of ZTF19abjethn (AT2019lvs)
  97. Fermi-LAT Gamma-ray Observations of IceCube-190629A
  98. LIGO/Virgo S190510g: J-GEM optical/NIR follow-up observations
  99. LIGO/Virgo S190425z: CAHA-GRANDMA Observation of the Swift UVOT Source
  100. LIGO/Virgo S190425z: Keck/MOSFIRE NIR spectroscopy of PS19qp (= AT 2019ebq)

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov