Edit: checked the actual paper, 250 is relative to galactic center, just like my sun number [0] [0] https://watermark.silverchair.com/staa1761.pdf?token=AQECAH

Edit: checked the actual paper, 250 is relative to galactic center, just like my sun number [0] [0] https://watermark.silverchair.com/staa1761.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAApkwggKVBgkqhkiG9w0BBwagggKGMIICggIBADCCAnsGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQMQjn01zD6JL4iHVhBAgEQgIICTC5U1KkQ8V28pu0e5ywTUXk7yyPjV0xKga4ckJCYCESMESq4xQ2v4juLQfGL8U7pvZG9Qr8TTQh6lTLLYoW8hZeeG25CCDdedZq-ORuIjRmGY7OdjeVuTXcwYOE-BJt5adB9QRjLw9mOtzLB3hrQuqrqfQf_Ddi5w0YKboESJTM2q9z3K8Gws7vmov4La4FJ6pg8Y0qBMzG-khSXhyr1Qaili203WHJUZo1iaFa_LZqN0AqjMJAs6dPduY6CRAarUXrCvpVWIpPYecwOX_YkLXWXVPZ9htz7W_UBHhXtjIYduJ8svRn6YscdOZyKEQktZ7NG_ufbPTLtZY1T_wO5sQdSLPHIyJSlDZBCk_mhSlcuekAmKEViDrxzRxYb7oWuLy5JUVX7qiLZXWRovQB_MEusQc8uOjg-76-pkTM3ouibG2yzmic_HR4S9jQYpyLzMr5cy3VdE-ROdOOadS6z9wBHQ8ZK2phteGYEGVOgoJephcc5Zy-4jueg4TVXInenn74kySZJv1rwEY6bojhe3uqirPre6UwQhdm8yfSyU8-uk3HlZZkUOS439zZDZ-HhXS4CEwQKzHlT_6azPBBgGYF1-y0bax34nF5JbNT577DqFSGYAvlW21sX7ip8fSLHKGdhctBHfpvbllCf1-FGGeTQt9qSpZ1NeTq6naPGGFLv1D158MKTpkj0ZgrHcBC69hkhLP9GChdigiH5NUwnInQxM3ux4Z8t3ufaR9q2GqVttathEL13c40t0Ou_cu2Eg0SJgep6j5DYb8xdLQ https://watermark.silverchair.com/staa1761.pdf?token=AQECAHi... We are in a milky way, it is reasonable to look at the speed relative to the galactic nucleus, which is what I did. Kind of how we talk about speed of earth/comets/etc around the sun.