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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"

16217 results found.

  1. GRB 241115A: Swift detection of a burst
  2. EP 241113a: LBT possible optical counterpart
  3. LIGO/Virgo/KAGRA S241114bi: Identification of a GW compact binary merger candidate
  4. GRB 241113A: PRIME near-infrared upper limits
  5. GRB 241113B: J-band upper limit from WINTER
  6. GRB 241113A: J-band observations with WINTER
  7. EP241113a : J-band observations with WINTER
  8. GRB 241030A: LCO optical observation
  9. GRB 241113B: Swift-XRT observations
  10. GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
  11. EP241113b/GRB 241113B: EP detection of GRB 241113B
  12. EP241113a: EP on-board trigger and autonomous follow-up observation
  13. GRB 241113A: Swift/UVOT Detection
  14. GRB 241113A: REM detection of the optical/NIR afterglow
  15. GRB 241113A: LCO optical observations
  16. GRB 241112B: GMG Optical Upper Limit
  17. GRB 241113A: Enhanced Swift-XRT position
  18. GRB241113A: LCOGT (40-cm) optical counterpart detection
  19. GRB 241113A: Swift detection of a burst with an optical counterpart
  20. SVOM/GRM detection of a short burst from SGR 1E1841-045
  21. GRB 241105A: ATCA Radio Upper Limits
  22. GRB 241112B: AbAO optical upper limit
  23. GRB 241107A: GROWTH-India telescope optical upper limit
  24. GRB 241112B: Optical afterglow detection confirmation in revisiting the Mephisto data
  25. GRB 241112B: Swift-XRT afterglow detection
  26. GRB 241112B: LCO optical detection of the SVOM/VT candidate
  27. GRB 241112B: Mephisto optical upper limits
  28. GRB 241112B: GOTO optical upper limits
  29. GRB 241107A: INTEGRAL IBIS localization
  30. EP241107a: EP-FXT follow-up observations
  31. LIGO/Virgo/KAGRA S241109bn: ATLAS observations and discovery of the potential counterpart AT2024aawt
  32. IPN triangulation of GRB 241107A (short/hard)
  33. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  34. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  35. INTEGRAL detection of a burst from 1E 1841-045
  36. EP241107a: AbAO optical upper limit
  37. GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
  38. EP241109a: confirmation of a stellar flare by BOOTES-7
  39. EP241109a: EP on-board trigger and autonomous follow-up observation
  40. EP241107A: MASTER optical observations of xray transient
  41. EP241107a: KAIT optical observations
  42. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  43. EP241107a: Kinder optical follow-up observations
  44. GRB 241025A: radio detection with the VLA
  45. EP241107a: AKO Optical Afterglow Follow-Up Observations
  46. GRB 241105A: EP-FXT follow-up observations
  47. GRB 241105A: SVOM/GRM observation
  48. EP241107a: OHP/T193 photometric and spectroscopic observations
  49. GRB 241105a: PRIME near-infrared upper limits
  50. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  51. EP241107a: GIT optical observations
  52. EP241107a: SVOM/C-GFT optical observations
  53. EP241107a: AKO Optical Afterglow Detection
  54. GRB 241025A: LBT optical observations
  55. EP241107a: EP on-board trigger and autonomous follow-up observation
  56. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  57. GRB 241105A: Swift/UVOT Detection
  58. GRB 241105A: Swift-XRT afterglow detection
  59. GRB 241104A: Swift-XRT observations
  60. GRB 240511A: LCO upper limits
  61. GRB 241104A: SVOM/VT optical candidate
  62. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  63. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  64. EP241104a: EP detection of GRB 241104A X-ray emission
  65. GRB 241010A: host galaxy redshift z = 0.977
  66. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  67. GRB 240821A: further radio observations with the VLA
  68. EP241101a: EP-FXT observations update
  69. EP241103a: GIT optical upper limit
  70. EP241021a: OHP/T193 further optical observations
  71. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  72. EP241103a: Swift XRT detection and improved X-ray position
  73. EP241021a: continued SOAR observations
  74. EP241101a: Optical upper limits with Kinder observations
  75. EP241101a: OHP/T193 optical observations
  76. EP241103a: EP observation update
  77. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  78. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  79. EP241103A: LCO optical observations
  80. EP241103a: an X-ray transient detected by Einstein Probe
  81. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  82. GRB241030A: OHP/T193 optical observations
  83. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  84. EP241101a: EP-WXT detection of a fast X-ray transient
  85. GRB 241101A: FRAM-ORM optical limit
  86. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  87. GRB 241101A: Swift-BAT refined analysis
  88. GRB 241030A: further SAO RAS optical observations
  89. GRB 241030A: Optical Observations via Virtual Telescope Project
  90. EP241021a: Liverpool Telescope optical follow-up observations
  91. GRB 241026A: SAO RAS optical observations
  92. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  93. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  94. EP241021a: OHP/T193 optical observations
  95. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  96. GRB 241030B: Montarrenti Observatory optical upper limit
  97. EP241026b: Liverpool Telescope optical follow-up
  98. GRB 241030A: SAO RAS optical observations
  99. EP241021a: AMI-LA radio detection
  100. GRB 241030B : GIT optical upper limits

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